Document Vj0YZZvLJbxp7yB3mejE5O90j

22132 RULES AND. REGULATIONS gras, shall be Of substantial, .rettflble 'dwifinttwm, -fTrrteh,-: or Other which the holding effect is obtained by construction and shall:be built or in- rigns. r;. .. the snubbing action of a flexible band ' . -stalled in a workmanlike manner- ; :<5) A sign-reading- "Exit",, or stmilar wrapped about a. cylindrical wheel or (2) Means of egress shall be continu designation, with , an arrow indicating drum affixedto the rotating member tote ously maintained free of all obstructions the direction, shall be placed in every held, the connections and linkages being or impediments to. full instant use in the location where the . direction. of travel so arranged that the motion of the brake of fire:orotfcer -emergency: to reach the nearest exitzis not immes wheel or drum will act to increase 'the v/;<3> Any device or. alarm installed to diateiy apparent. . 1. :; '-' : : " . tension or holding force of the band...... restrict the improper use of as exit shall - (6) Every exit sign shad be suitably : (6) Brake--shoe type. A brake in be so designed and installed that it can* illuminated by a reliable light source which the holding effect is obtained by not,, even in cases of failure. Impede or giving a value of not less titan 5-foot applying the direct pressure of two or prevent emergency use of such exit. candles on the illuminated surface.Arti more segmental friction elements held to (1) Furnishings and decorations. Cl) ficial lights giving illumination to exit a stationary member against a cylindrical No furnishings, decorations, or other ob signs otter than the internally .illumi wheeL or drum affixed to the rotating jects shall be so placed as to obstruct nated types shall have screens,. discs, member to be held. exits, access thereto, egress therefrom, or lenses of not less than 25 square (7) Building face rollers. A specialized or visibility thereof. - - : inches area made of translucent mate form of guide roller designed to contact (2) No furnishings or decorations of rial to show red or other specified desig b portion of the outer face or wall struc an explosive or highly flammable charac nating color on the side of the approach. ture of the building, and to assist in ter shall be used in any occupancy. (7) Each internally illuminated exit stabilizing- the operators' platform dur (m> Automatic sprinkler systemsi All sign shall be provided in all occupancies ing vertical travel. automaticsprinklersystems shall be-con Where reduction Of normal IWnmtnatiwr* " (81 Continuous pressure. Operation tinuously maintained in reliable oper ispermitted. i-: by means of buttons or switches, any one ating condition at all., times, and such (8) Every exit sign shaJi have tiie of which may be used, to control the periodic.-inspections and tests shall be word "Exit" in plainly legible tetters not movement of the working platform or made:as are-necessary to assure proper less than 6 inches bigh^ with the .prin roof car, "only as;long.;as the button or maintenance. vc vih'i? cipal strokes of letters - not. less than switch is manually maintained in the . (n) -Alarm and fire protection systems. three-fourths-inch wide. ' S'l?.r. actuating position: (1) Systems shall be under the super vision of a responsible person who shall cause proper tests to be made at weekly intervals and have general eharge of all alterations and additions. 1910.38 Specific means of egress requiretnents by occupancy. [Re served] 1910.39 Sources of standards. ` (9) Control. A system governing starting, stopping, direction, accelera tion, speed, and retardation of moving members. (10) Controller. A device or group of (2) Fire alarm signaling equipment The entire subpart is promulgated devices, usually contained in a single shall be restored , to service as promptly from NFTA 101-1970, Life Safety Code: enclosure, which serves to control in as possible after each test or alarm, and shall be kept in normal condition for operation. Equipment requiring rewind 1910.40 Standards organizations. - Specific standards, of . the following some predetermined 1 maimer the ap paratus to which it is- connected. (Ill Electrical ground. A conducting ing or replenishing -shall be rewound or organization have been referenced in connection between an electrical circuit replenished as promptly as possible after this subpart. Copies of the-standardsmay or equipment and the earth, or some eachtest or alarm. . be obtained from the issuing organi conducting body which serves in place ; (o) Fire retardant paints. Fire retard zation: of the earth. ant paints or solutions shall be renewed National Fire Protection Association, 60 (12> Guide rotter. A rotating, bear at such intervals as necessary to main Batterymarch Street, Boston, MA 03110. - . ing-mounted, generally cylindrical tain.the necessary flame retardant prop- erties. ::r(p>-'[Reserved! : ............. .. member-operating separately or as part Subport F--Powered Platforms, Maiw of a guide shoe assembly, attached to Clifts* and Vehicle-Mounted Worth the platform, and providing rolling con iq)Exit marking, (l) Exits shall be -Platforms tact with building guideways, or other marked by a readily visible sign. Access to exits shall be marked by readily visible signs in all cases where the exit or way.to reach it is not immediately visible to the .occupants. V<2) Any- door, passage, or stairway, 1910.66 Power platforms for exterior, building maintenance. -. - . (al DeAarfiorts applicable to this sec* tkm--a) Ansrulated raping. A system of platform suspension in which tide upper building contact members. (131 Guide shoe. An assembly of roll ers, slide members, or the equivalent, attached as a unit to the operators* plat form,. and designed to engage with the building members provided for the ver which'is neither an exit nor a way of exit wire rope sheaves or suspension potato tical guidance of the operators* access, and which is so located or ar axe closer to the plane of the building platform. ranged as to be likely.to be'mistaken face tiian the corresponding attachment .. . (14) .Interlocks. A device actuated by- fof-an exit, shall be identified by a sign points on the platform, thus causingthe the operation of .some, other device with - reading '`Not an Exit" or similar desig-: platform to press against the face of the which it to directly associated, to govern nation, or shad be Identified by assign building during its vertical travel. - > r-J succeeding operations*'of the same or indicating its actual character, such as (2) ANSI. American National Stand-: allied devices. "To Basement," "Storeroom," 'Tdnen ards Institute.. `-'I c (151- Operating device. A pushbutton, CloseV or the like. (3) Babbitted fastenings. The method lever,- or other manual device used to (3) Every required sign designatingan- of providing wire roper attachments: in actuate a control. exitf or way of exit access shall be so lo- which the ends of the' Wire strands are - (181 Powered platform. Equipment to . - csted and of such size, color, and design bent back and are held in' a .tapered: provide access to the exterior of a budd as to -be readily visible. No decorations,' socket by means of pouredmolten babbitt ing for maintenance, consisting of a sus furnishings, or equipment which impair metal. - '. 'ir pended power-operated working plat visibility of an exit sign shall be per- . : <4> Brake--disc type. A brake In which form,; a-yoofcsur,orr other suspension v^mitted, nor shall there be any- brightly' Ore bolding effect ia stained by frfe-t meate, and 4he reepiteite operating and .^Illuminated sign (for other than exit tional resistance between ohe or mote control devices; := -v _ .-r?Nj purpose):, display, or object in or near faces ofdiscs keyed to therotating mem-. U7)Kofed toad. The combined weight > therhne'tdL'vision to the reqmred exife ber to be hefciandfixBd discs.'keyed. to.` of employees, toolsr equipment, and other * 1`jsign'ofsuch.a character as to so detract: thftstationary or housing member (pres materislwfaicbthe working platform is v jvnattentiomfrom the exit sign that it may: sure between . the; discs being applied designed And installed to lift. t y^^jotberKrficed. - -- ( -j> liWl^Jlelay; direetion. An- electrically ^ -,a.44> Every exit sign, shall be .distinctive? (5X Brute--seii-energtsing.bandSvpe^ fmergized rcontactor responsive to an - ^`^htcdtorand shall provide contrastwith. An essentially unidirectional brake da: initiating .control circuit, which In tun* , co SDEKAl REGISTER,LV6L. 37, NO. 202--WEDNESDAY, OCTOBER ir,v19?Z' f. f- .........' ' . . v^V . ,, - -* WEDNESDAY, OCTOBER 18, 1972 WASHINGTON. D.CSg Volume 37 * Number 202:*- PART II DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND. HEALTH ADMINISTRATION OCCUPATIONAL SAFETY AND HEALTH STANDARDS BFG30372 22102 / RULES AND REGULATIONS Title 29--LABOR Chapter XVII--Occupational Safety and Health Administration, Depart ment of Labor:.- PART 1910--OCCUPATIONAL SAFETY AND HEALTH STANDARDS Pursuant to authority in sections 6 and 8(g) of the Williams-Steiger Occupa tional Safety and Health Act of 1970 (84 Stat. 1593, 1600; 29 UB.C. 655, 657) and iiv Secretary of Labor's Order No. 12-71 (36 F.R. 87.54), Part 1910 of Title 29 of the Code of Federal Regulations is hereby revised to read as set forth be low. This revision includes amendments through Sept. 22, 1972. The purpose of the revision is (1) to publish fully in one place the present occupational safety and health standards contained therein in order, to reflect many changes made during the current year and thereby to improve their usefulness and facilitate their enforcement; (2) to correct a num ber of typographical and clerical errors in the text of the standards; and (3) to publish indexes with the standards, which are intended to permit quicker access to pertinent standards. Since this revision does not make any substantive changes in the standards, it is not necessary to provide notice of pro posed rulemaking, opportunity for pub lic participation therein, nor any delay in effective date. For the same reason, good cause Is found for not following the regular procedure for rulemaking pro vided in 5 U.S.C. 553 and for making this revision effective immediately. Signed at Washington, D.C. this 4 day of October 1972. G. C. Guenther, Assistant Secretary of Labor. Sec. 1910.1 1910.2 1910.3 1910.4 1910.5 1910.6 Subpart A--General purpose and scope. Definitions. Petitions for the issuance, amend ment, or repeal of a standard. Amendments to this part. Applicability of standards. Incorporation by reference. Subport B--Adoption and Extension of Established Federal Standards 1910.11 1910.12 1910.13 1910.14 1910.15 1910.16 1910.17 1910.18 1910.19 Scope and purpose. Construction work. Ship repairing. Shipbuilding. Shipbreaking. Longshoring. Effective dates. Changes in established .standards. Asbestos dust. Federal Subpart C-- {Reserved) Subpart D--Walking--Working Surfaces 1910.21 191022 1910.23 1920.24 1910.25 1910.26 Definitions. General requirements. Guarding.floor and wall openings and holes. Fixed industrial stairs, Portable wood ladders. Portable metal ladders. 1910.27 1910.28 1910.29 1910.30 1910.31 Fixed ladders. Safety requirements for scaffold ing. Manually propelled mobile ladder stands and scaffolds (towers). Other working surfaces. Sources of standards. Sec.' 1920:248 Standards organizations. 1910.149 Effective dates. Subpart K--Medical and First Aid 1910.151 Medical services and first aid. 1910.152 [Reserved] 1910.153 Sources of standards. 191022 Standards organizations. 5ubport l----Fire Prelection 1910.35 1910.36 1910.37 191028 191039 1910.40 Subpart E--Means of Egress Definitions. General requirements. Means of egress, general. Specific means of egress require ments by occupancy. [Reserved] Sources of standards. Standards organizations. Subpart F Powered Platforms, ManlifJs and Vehicle-Mounted Work Platforms 1910.66 1910.67 Power platforms for exterior build ing maintenance. Vehicle-mounted elevating and ro tating work platforms. 1910.156 Definitions applicable to this subpart. Portable Pies Suppression equipment 1910.157 Portable fire extinguishers. 1910.158 Standpipe and hose systems. Fixed Fire Suppression Equipment 1910.159 1910.160 1910.161 1910.162 Automatic sprinkler systems. Fixed dry chemical extinguishing systems. Carbon, dioxide extinguishing systems. Other special fixed extinguishing systems. [Reserved] 1910.68 1910.69 1910.70 Manlllts. Sources of standards. Standards organizations. Other fire Protection Systems 1910.163 Local fire alarm signaling systems. 1910.164 Fire brigades. [Reserved] Subport G--Occupational Health and Environmental Control 1910.93 1910.93a 1910.94 1910.95 191096 1910.97 191098 191099 1910.100 Air contaminants. Asbestos. Ventilation. Occupational noise exposure. Ionizing radiation. Nonionizing radiation. Effective dates. Sources of standards. Standards organizations. 1910.165 Effective dates. 1910.165a Sources of standards. 1910.165b Standards organizations. Subpart M--Compressed Gas and Compressed Air Equipment 1910.166 1910.167 1910.168 Inspection of compressed gas cyl inders. Safety relief devices for com pressed gas cylinders. Safety relief devices for cargo and portable tanks storing com Subport H- Hazardous Materials 1910.101 Compressed gases (general require ments) . 1910.102 Acetylene. 1910.103 Hydrogen. 1910.104 Oxygen. 1910.105 Nitrous oxide. 1910.106 Flammable and combustible liquids. 1910.107 Spray finishing using flammable and combustible materials. 1910.108 Dip tanks containing flammable or combustible liquids. 1910.109 Explosives and blasting agents. 1910.110 Storage and handling of liquified petroleum gases. 1910.169 1910.170 1910.171 pressed gases. Air receivers. Sources of standards. Standards organizations. Subpart N--Materials Handling and Storage 1910.176 1910.177 1910.178 1910.179 1910.180 I 1910.181 1910.182 1910.188 1910.184 Handling materials--general. Indoor general storage. Powered industrial trucks. Overhead and gantry cranes. Crawler, locomotive, and truck . cranes. Derricks. Effective dates. Sources of standards. Standards organizations. 1910. ill 1910.112 1910.113 1910.114 1910.115 1910.116 Storage and handling of drous ammonia. [Resemdl [Reserved] Effective dates. Sources of standards. Standards organizations. anhy Subpart I--Personal Protective Equipment 1910.132 1910.133 1910.134 1910.135 1910.136 1910.137 1910.138 1910.139 1910.140 General requirements. Eye and face protection. Respiratory protection. Occupational head protection. Occupational foot protection. Electrical protective devices. Effective dates. Sources of standards. Standards organizations. Subpart --Machinery and Machine Guarding 1910.211 Definitions. 1910-213 General requirements for all ma chines. 1910.218 Woodworking machinery require ments. 1910.214 Cooperage machinery. 1910.215 Abrasive wheel machinery. 1910216 Mills and calenders in the rubber and plastics Industries. 1910-117 Mechanical power presses. 1910.218 Forging machines, 1910.219 Mechanical power-transmission ap paratus. 1910.220 Effective dates. 1910.221 Sources of standards. 1910.222 Standards organizations. Subpart J--General Environmental Controls Subpart h--Hand and Portable Powered Tools and Other Hand-Held Equipment 1910.141 Sanitation. 1910.142 Temporary labor camps. 2010.241 Definitions. 1910.143 Nonwater carriage disposal 1610.243 Hand and portable powered tools systems. 1910.144 Safety color code for marking physical hazards. a-nrt equipment, general. 1910.243 Guarding of portable powered tools. 1910.244 Other portable tools and equlp- 1910.145 Specifications for accident preven ment. tion signs and tags. ' 1910.245 Effective dates. 1910.146 [Reserved] 1910.246 Sources of standards. 1910.147 Sources of standards. 2910.247 Standards organizations. BFG30373 FEDERAL REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER 18,1972 RULES. AND. REGULATIONS 22131 1910.37 Means of egress, general. any floor, balcony, tier, or other occupied : (2> Exterior ways of exit -access shall fa) Permissible exit components. An space shall be sufficient for the occupant shall consist only of .the approved ponents. Exit components shall be Cuostructed as an integral part of the load thereof. The occupant load shall be - the TUftTimiTm may be in the number: of persons that space at any time. - . (2) Where exits serve more than one building or shall be permanently affixed floor; only the occupant- load of each thereto. tb) Protective enclosure of exits. When an exit is protected by separation from other parts of the building the floor considered individually need be used in computing the capacity of the exits at that floor, provided that exit capacity shall not be decreased in the separating construction shall meet the direction of exit travel. following requirements. (e) Arrangement of exits. When more (1) The separation shall have at least than one exit is required from a story, at a 1-hour Are resistance rating when the least two of the exits shall be remote exit connects three stories or less. This applies whether the stories connected are from each other and so arranged as to minimize any possibility that both may above or below the story at which exit discharge begins. be blocked by any one fire or other emer gency condition. (2) The separation Khali have at least (f) Access to exits. (1) Exits shall be a 2-hour fire resistance rating when the so located and exit accesss shall be so exit connects four or more stories, arranged that exits axe readily accessi whether above or below the floor of dis ble at all times. Where exits are not im charge. It shall be constructed of non mediately accessible from an open floor combustible materials, and shall be area, safe and continuous passageways, supported by construction having at aisles, or corridors leading directly to have amootivsolid Soars, substantially level, and shall have guards on the un enclosed sides. . .. . 1 (3>-Where accumulation of snow or ice is likely because of the climate, the exterior way of exit access shall be pro tected by-a roof, unless it serves .as the sole normal means of access to the rooms or spaces served, in which case it may be assumed that snow and ice will be regularly removed in the course of nor mal occupancy. (4> A permanent, reasonably straight path of travel shall be maintained over the required exterior way of exit access. There shall be no obstruction by rail ings, barriers, or gates that divide the open space into sections appurtenant to individual rooms, apartments, or other uses. Where the Assistant Secretary of Labor or his duly authorized representa tive finds the required path of travel to be obstructed by furniture or other mov able objects, he may require that they be fastened out of the way or he may re least a 2-hour fire resistance rating, (3) Any opening therein shall be pro tected by an approved self-closing fire every exit and so arranged as to provide convenient access for each occupant to at least two exits by separate ways of quire that railings or other permanent barriers be installed to protect the path of travel against encroachment. door, (4) Openings in exit enclosures shall be confined to those necessary for access to the enclosure from normally occupied spaces and for egress from the enclosure. ic) Width and capacity of means of egress. (1) The capacity in number of persons per unit of exit width for ap proved components of means of egress -'"nil be as follows: l) Level Egress Components (includ^ Class A Ramps) 100 persons. >.ii) Inclined Egress Components (in cluding Class B Ramps) 60 persons. iiii) A ramp shall be designated as Class A or Class B in accordance with the following Table E-l: Table E-l Class A Class B With.................... 44 indies unit 30 to 44 inches. Blcjn*.................... XMe to 2 Inches Hiiimnm height No limit.. _____ . 12 feet. t^tween landiigrs- travel, except as a single exit or limited. (5> An exterior way of exit access dead ends are permitted by other pro shall be so arranged that there are no visions of this subpart, shall be main dead ends in excess of 20 feet. Any un tained. enclosed exit served by an exterior way (2) A door from a room to an exit or of exit access shall be so located that no to a way of exit access shall be of the part of the exit extends past a vertical side-hinged, swinging type. It shall swing plane 20 feet and one-half the required with exit travel when the room is occu width of the exit from the end of and at pied by more than 50 persons or used for right angles to the way of exit access. a high hazard occupancy. (3) In no case shall access to an exit be through a bathroom, or other room (6> Any gallery, balcony, bridge, porch or other exterior exit access that projects beyond the outside wall of the building subject to locking, except where the exit is required to serve only the room sub ject to locking. (4) Ways of exit access and the doors to exits to which they lead shall be so designed and arranged as to be clearly recognizable as such. Hangings or drap eries shall not be placed over exit doors or otherwise so located as to conceal or obscure any exit. Mirrors shall not be placed on exit doors. Mirrors shall not be placed in or adjacent to any exit in such a manner as to confuse the direction of exit. (5) Exit access shall be so arranged shall comply with the requirements of this section as to width and arrange ment. (h> Discharge from exits. (1) All exits shall discharge directly to the street, or to a yard, court, or other open space that gives safe access to a public way. The streets to which the exits discharge shall be of width adequate to accommodate all persons leaving the building. Yards, courts, or other open spaces to which exits discharge shall also be of adequate width and size to provide all persons leaving th*4>uflding with ready access to that it will not be necessary to travel tiie street. toward any area of high hazard occu (2) Stairs and other exits shall be so (2) Means of egress shall be measured pancy in order to reach the nearest exit, arranged as to make clear the direction in units of exit width of 22 inches. Frac unless the path of travel is effectively of egress to the street. Exit stairs that tions of a unit shall not be counted, ex cept that 12 inches added to one or more full units shall be counted as one-half a unit of exit width. (3) Units of exit width shall be meas shielded from the high hazard location by suitable partitions or other physical barriers. (6) The minimum width of any way of exit access shall in no case be less than continue beyond the floor of discharge shall be interrupted at the floor of dis charge by partitions, doors, or other ef fective means. (i> Headroom. Means of egress shall ured in the clear at the narrowest point 28 inches. Where a single way of exit be so designed and maintained as to pro of the means of egress except that a access leads to an exit, its capacity In vide adequate headroom, but in no case handrail may project inside the meas terms of width shall be at least equal to shall the ceiling height be less than 7 ured width on each side not more than 5 the required capacity of the exit to which feet 6 inches nor any projection from the Inches and a stringer may project inside it leads. Where more than one way of ceiling be less than 6 feet 8 inches from the measured width not more than 1^ exit access leads to an exit, each hil the floor. inches. An exit or exit access door swing have a width adequate for the number (j) Changes in elevation. Where a ing into an aisle or passageway shall not. of persons it must accommodate. means of egress is not substantially restrict the effective width thereof - at any point during its swing to less than the minimum widths hereafter specified. (g) Exterior wails of exit access. (1) level, such differences in elevation shall Access to an exit may be by means of any be negotiated by stairs or ramps. exterior balcony, porch, gallery, or roof (k) Maintenance and workmanship r.d) Egress capacity and occupant load.- that conforms to the requirements of this (1) Doors,'stairs, ramps, passages, signs, > The capacity of means of egress for- section. and an.other components of means of FEDERAL REGISTER, VOL 37, NO. 202. WEDNESDAY, OCTOBE 13, 1972. 24358016 22130 RULES AND REGULATIONS Standard ri: ........... Source- :. -- winch neither poisonous fumes nor ex S 191026_______--- ANSI A142-1956, Factable Metal Ladders. ANSI AI4.S-1956, Safety Code for Fixed lad ders..............S 193028 ....____ - ANSI A10.8-I969,Safety plosions are to be feared in case of fire. : (h) Approved.Forthepurposes of this subpart approved shall mean listed or approved equipment by a nationally rec ognized testing laboratory. - . 11910.29 _ . ..Req-alrementalax Scaffolding. ------- ANSI A92.1-1971, Standard _or Manually pro 2910.36 General requirements. (a) Application. This subpart contains general fundamental requirements es pelled Mobile Ladder Stands and Scaffolds. I 1910.30(6) ANSI B56.1--1969, Safety Standard for Powered Industrial Trades. S 1910.30(b)____ANSI B24.I-1963, Safety Standard for Forging. sential to providing a safe means of egress from fire and like emergencies. Nothing in t.hia subpart shall be con strued to prohibit a better type of build ing construction,more exits, or otherwise safer conditions.than the minimum re quirements specified in this subpart. I 1910.30(c)_______ ANSI 01.1-1954, Safety Code for Woodwork-, lng Machinery. Exits from vehicles, vessels, or other mo bile structures are not covered by this subpart.' : . 1910.32 Standards organizations. . The following organizations have been referenced in this SubpartD: American National Standards Institute. 1430 Broadway. New York, NY 10018. Underwriters' Laboratories, Inc., 207 Bast (b) Fundamental requirements. (1) Every building or structure, new or Old, designed for human occupancy shall be provided with exits sufficient to permit the prompt escape of occupants in case of fire or other emergency. The.design of ' Ohio Street, Chicago, XL 6061L Factory Mutual Engineering Corp., Post Office Box 688, Norwood, MA 02062. exits and other safeguards shall be such that reliance for safety to life in case of fire or other emergency will not depend Subpart E--Means of Egress 1910.35 Definitions. solely on any single safeguard; addi tional safeguards shall be provided for life safety in case any single safeguard As used in this subpart is ineffective due to some human or me (a) Means of egress.A means of egress chanical failure. is a continuous and unobstructed way of (2) Every building or structure shall exit travel from any point in a building be so constructed, arranged, equipped, or structure to a public way and consists maintained, and operated as to avoid of three separate and distinct parts; the undue danger to the lives and safety of way of exit access, the exit, and the way its occupants from fire, RrnQkp, fumes, or of exit discharge. A means of egresscom resulting panic during the period of time prises the vertical and horizontal ways of reasonably necessary for escapefrom the travel and shallinclude intervening room building or structure in. case of fire or spaces, doorways, hallways, corridors, other emergency. , ; passageways, balconies, ramps, stairs, (3) Every building or structure shall enclosures, lobbies, escalators, horizontal be provided with exits of kinds, numbers, exits, courts, and yards. location, and capacity appropriate to the (b) Exit access. "Exit access is that individual building or structure, with due portion of a means of egress which leads regard to the character of the occupancy, to an entrance to an exit the number of persons exposed, the fire <c> Exit. Exit is that portion of a protection available, and the height and means of egress which is separated from type of constructicai erf the building or all other spaces of the building or struc structure, to afford all occupants con ture by construction or equipment as venient facilities for escape. required in thi subpsrt to provide a pro tected way of travel to the exit discharge. (d) Exit discharge. Exit discharge is that portion of a means of egress be tween the termination of an exit and a public way. (e) Low hazard contents. Law hazard (4) hi every building ex structure exits shall be so arranged and maintained as to provide free and unobstructed egress from all parts of the building or struc ture at all times when it is occupied. No lock or fastening to prevent free escape from the inside of any building shall be contents shall be classified as those of installed except in mental, penal, or cor such low combustibility that no self- rective institutions where supervisory propagating fire therein can occur and personnel is continually on duty and ef that consequently the only probable dan fective provisions are made to remove ger requiring the use of emergency exits occupants in case of fire or other will be from panic, fumes, or smoke, or emergency. fire from some external source. : : (f) High-hazard contents. High-haz ard contents shall be classified as those .which are liable to bum with extreme rapidity or from which poisonous fumes ' orexplosions are to be feared in the event Of fire. (5> Every exit shall be (dearly visible or the route to reachit *hil be conspicu ously indicated In such a manner that every occupant of every building or structure, who is physically and mentally capable will readily know the direction of escape from any point, and each path (g) Ordmarv hazard contents. .Ordi of escape, in its entirety; shall be so nary hazard 'contents shad be classified arranged or marked that the way^to a as-thase which are liable to bum with place of safety outside is unmfstakable. .moderate rapidity and to give off a con Any doorway or passageway not consti siderable volume of smoke but from tuting an exit or way to reach an iexit; but of sigh a character as to be subject to being mistaken for an exit, shall be so arranged or marked as to minimize its possible confusion with an exit and the resultant danger of persons endeavoring to escape from, fire finding themselves trapped in a dead-end space, such as a cellar or storeroom, from which there is no other way out. (6) ha every building or structure equipped for artificial illumination, ade quate and reliable illumination shall be provided for all exit facilities. (7) In every building or structure of such size, arrangement, or occupancy that a fire may not Itself provide ade quate warning to occupants, fire alarm facilities shall be provided where neces sary to warn occupants of the existence of fire so that they may escape, or to facilitate the orderly conduct of fire exit drills. (8) Every building or structure, sec tion, or area thereof of such size, occu pancy, and arrangement that the reason able safety iff numbers of occupants may be endangered by the blocking of any single means of egress due to fire or smoke, shall have at least two means of egress remote from each other, so ar ranged as to minimize any possibility that both may be blocked by any one fire or other emergency conditions. (9) Compliance with this subpart shall not be construed as eliminating or reducing the necessity for other provi sions for safety of persons using a struc ture under normal occupancy conditions, nor shall any provision of the subpart be construed as requiring or permitting any condition that may be hazardous under normal occupancy conditions. Cc> Protection of employees exposed by construction and repair operations. (D No building or structure under con struction shall be occupied In whole or in part until an exit facilities required for the part occupied are completed and ready for use. (2) No existing building shall be occu pied during repairs or alterations unless all existing exits and any existing fire protection are continuously maintained, or in lieu thereof other measures are taken which provide equivalent safety. (3> No flammable or explosive sub stances or equipmentfor repairs or alter ations ha be introduced in a building of normally low or ordinary hazard clas sification while the building is occupied, unless-the condition of use and safe guards provided are snch as not to create any additional danger or handicap to egress beyond the normally permissible conditions in the building. (d) Maintenance. (1> Every required exit, way of approach thereto, and way of travel from the exit into the street or open space, shall be continuously main tained free of all obstructions or impedi ments to fun use hi the case of fire or other emergency. - <2> Every automatic sprinkler system, fire detection and a-iarm system, exit KghtingV fire door, and other Item of equipment, where provided, shall be con tinuously in proper operating condition. FEDERAL REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER' T 3, 1972 RULES AND- REGULATIONS 22103 Swbpetl Q--Welding, Culling end Brazing who has employees, but does not lnclnde satisfy the requirements of the definition 1910.251 Definitions. 1910.252 Welding, catting and brazing. the United States or any State or poli of "national consensus standard" in tical subdivision of a State;,; ;. . secthxn3(9) of the Act..:. 1910.253 Sources of standards (d) ``Employee'*means an employee of Within a reasonable time after the 1910.254 Standards organizations. an employer who is employed in a busi receipt of a submission pursuant to sub- Subport R--Special Industries 1910.261 1910.262 1910.263 1910.264 Pulp, paper, and paperboard mills. Textiles. Bakery equipment. Laundry machinery and opera tions. ness of his employer which affects com merce; ", - . -'-f.r (e) "Commerce" means trade, traffic, commerce,- transportation, or communi cation among the several States, or be tween a State and any place outside paragraph U) of this paragraph, the .As sistant Secretary of Labor shall publish or canse to be published in the Federal Bbbzstbr a notice of such submission, and shall afford interested persons a reason able opportunity to present written data, 1910.265 Sawmills. thereof, or within the District of Colum views, or arguments with regard to the 1910.266 1910.267 1910268 1910.269 Pulpwood logging. Agricultural operations. Sources of standards. Standards organizations. Subpart S--Electrical bia, or a possession of the United States (other than the Trust Territory of the Pacific Islands), or between points in the same State but through a point outside thereof; - question whether any standards of the organization making the submission are naf-rrvnal wmspngtls standards. 1910.4 Amendments to this part. ' 1910.308 Application. 1910.309 National Electrical Code. Subject Index for 29 CFR 1910--Occupa (f) "Standard" means a standard which requires conditions, or the adop tion or use of one or more practices, (a) The Assistant Secretary of Labor shall have all of the authority of the Secretary of Labor under 3(9) and tional Safety and Health Standards. AuthorITT: The provisions of this Part 1910 issued under secs. 6(a), 8(g), 84 Stat. 1593. 1598; 29 U.S.C. 655, $57. Subpart A--General 1910.1 Purpose and scope. (a) Section 6(a) of the WilliamsSteiger Occupational Safety and Health Act of 1970 (84 Stat. 1593) provides that "without regard to chapter 5 of title 5, United States Code, or to the other sub sections of this section, the Secretary shall, as soon as practicable during the period beginning with the effective date of this Act and ending 2 years after such date, by rule promulgate as an occupa tional safety or health standard any na- ionaT consensus standard, and any esabllshed Federal standard, nmess he determines that the promulgation of such a standard would not result in im proved safety or health for specifically designated employees." The legislative purpose of this provision is to establish, as rapidly as possible and without regard to the rule-making provisions of the Ad ministrative Procedure Act, standards with which industries are generally fa miliar, and on whose adoption interested and affected persons have already had an opportunity to express their views. Such standards are either (1> national con census standards on whose adoption af fected persons have reached substantial agreement, or (2) Federal standards al ready established by Federal statutes or regulations. .. (b) This part carries out the directive means, methods, operations, or processes, 6(a) of the Act. reasonably necessary or appropriate to (b) The Assistant Secretary of Labor provide safe or healthful employment may at any time before April 28, 1973, and places of employment; on his own motion or upon the written (g) "National consensus standard" petition of any person, by rule promul means any standard or .modification, gate as & standard any national con- thereof which (1) has been adopted and sawns standard and any established promulgated by- a nationally recognized Federal standard, pursuant to and in standards-produeing organization under accordance with section 6(a) of the Act, procedures whereby it can be determined and, in addition, may modify or revoke by the Secretary of Labor or by the As any standard in this Part 1910. In the sistant Secretary of Labor that persons event of conflict.among any such stand interested and affected by the scope or ards; the Assistant Secretary of Labor provisions of the standard have reached shall take the action necessary to elimi substantial agreement on its. adoption, nate the conflict, including the revoca (2) was formulated in a manner which tion or modification of a standard in this afforded an opportunity for diverse views part, so as to assure the greatest protec to be considered, and (3) been des tion of the safety or health of the af ignated as such a standard by the Sec fected employees. . retary or the Assistant Secretary, after 1910.5 Applicability of standards. consultation with other . appropriate Federal agencies; and (h) "Established Federal standard" means any operative standard estab lished by any agamy of the United States and in effect on April 28, 1971, or contained in any Act of Congress in force on the date of enactment at the Williams-Steiger Occupational Safety and Health Act. 1910.3 Petitions for the issuance, amendment, or repeal of a standard, ' (a) Except as provided in paragraph (b) of *hig section, the standards con tained in this part shall apply with re spect to employments performed in a workplace in a State, the District of Columbia, the Commonwealth of Puerto Rico, the Virgin Islands, American Raman, Guam, Trust Territory of the Pacific Islands, Wake Island, Outer Con tinental Hhif lands defined in the Outer Continental Shelf Lands Act, Johnston TdanA, and the Canal Zone. (a) Any interested person may peti (b> None of the standards in this part tion in writing the Assistant Secretary shall apply to working conditions of em of Labor to promulgate, modify, or re ployees with respect to which Federal voke a standard. The petition should net agencies other than the Department of forth tite terms or the substance of the Labor, or State agencies acting under rule desired, the effects thereof if pro section 274 of the Atomic Energy Act of mulgated, and the reasons therefor. 1954, as amended (42 UJ3.C. 2021), exer to the Secretary of Labor under section <b) (1) The relevant legislative his cise statutory authority to prescribe or 6(a) of the Act. It contains occupational tory of the Act indicates congressional enforce standards or regulations affect safety and health standards which have recognition of tiie American National ing occupational safety or health.' been found to be national consensus Standards Institute and the National ;; <C> (1) If a particular standard is standards or established Federal stand Fire Protection Association as the major specifically applicable to a condition, ards. sources of national consensus standards. practice, means, method, operation, or 1910.2 Definitions. National consensus standards adopted on process, it shall prevail over any different May 29, 1971, pursuant to section 6(a) general standard which might otherwise As used in this part, unless the con of the Act are from those two sources. be applicable to the same condition, prac text clearly requires otherwise: However, any organization which deems tice, means, method, operation, or ' (a) "Act" means the Williams-Steiger itself a producer of national consensus process. For example, 150123(c) (3) of Occupational Safety and Health Act of standards, within the meaning of sec this title prescribes personal protective 1970 (84 Stat. 1590). tion 3(9) of the Act, is invited to submit equipment for certain ship repairmen (b) "Assistant Secretary of Labor" in writing to the Assistant Secretary of working In specified areas. Such a stand means the Assistant Secretary of Labor Labor at any time prior to February' 1, ard shall apply, and shall not be deemed 'or Occupational Safety and Health; - ' 1973, all relevant irfonnation -which modified nor supersededby any different 'c> "Employer" means a person en- may enable the-Assistant-Secretary to general standard'whose provisions'might -ged in a business affecting commerce determine whether any of its standards otherwise be applicable, to the ship re- i FEDERAL REGISTER, VOL E3r, NO. 20T--WEDNESDAY, OCTOHER 13, 1972 BFG30374 22104 RULES AND REGULATIONS pairmen working in the areas specified in 1915.23(c) (3>. '(2) On the other hand, any standard shall apply according to its terms to any employment and place of employment in any industry, even though particular standards are also prescribed for the in dustry, as in Subpart B or Subpart R of this part, to the extent that none of such particular standards applies. To illus trate, the general standard regarding noise exposure in 1910.95 applies to employments and places of employment in pulp, paper, and paperboard mills cov ered by 1910.261. (d> In the event a standard protects on its face a class of persons larger than employees, the standard shall be ap plicable under this part only to employees and their employment and places of employment. <e) [Reserved] (f) An employer who is in compliance with any standard in this part shall be deemed to be in compliance with the re quirement of section 5(a)(1) of the Act, but only to the extent of the condition, practice, means, method, operation, or process covered by the standard. 1910.6 Incorporation by reference. (a) The standards of agencies of the U.S. Government and organizations which are not agencies of the UJ3. Gov ernment which are legally incorporated by reference in this part, have the same force and effect as other standards in this part, (b) Copies of the standards which are incorporated by reference may be ex amined at the national office of the Oc cupational Safety and Health Adminis tration, U.S. Department of Labor, Wash ington, D.C. 20210, or at any of its regional offices. Copies of such private standards may be obtained from the is suing organizations. Their names and addresses are listed in the pertlnmt sub parts of this part. (c) Any changes in the standards in corporated by reference in this part and an official historic file of such changes are available for inspection at the na tional office of the Occupational Safety and Health Administration, U.S. Depart ment of Labor, Washington, D.C. 20210. Subpart B--Adoption and Extension of Established Federal Standards 1910.11 Scope and purpose. The provisions of this Subpart B adopt, and extend the applicability of, estab lished Federal standards in effect on April 28, 1971, with respect to every em ployer, employee, and employment cov ered by the Act. 1910.12 Construction work, . (a) Standards. The standards pre scribed in Part 1926 of this chapter are adopted as occupational safety and health standards under section 6 of the Act and shall apply, according to the pro visions thereof, to every employment and place of employment of every employee engaged in construction work. Each em ployer shall protect the employment and places of employment of each of his em ployees engaged in construction work by complying with the appropriate stand ards prescribed in this paragraph. (b) Definition. For purposes of this section, "construction work" means work for construction, alteration, and/or re pair, including painting and decorating. See discussion of these terms in 1 1926.13 of this title. (c) Construction Safety Act distin guished. This section adopts as occupa tional safety and health standards under section 6 of the Act the standards which are prescribed in Part 1926 of this chap ter. Thus, the standards (substantive rules) published in Subpart C and the following subparts of Part 1926 of this chapter are applied. This section does not incorporate Subparts A and B of Part 1926 of this chapter. Subparts A and B have pertinence only to the ap plication of section 107 of the Contract Work Hours and Safety Standards Act (the Construction Safety Act). For ex ample, the interpretation of the term "subcontractor" in paragraph (c) of 1926.13 of this chapter is significant in discerning the coverage of the Construc tion Safety Act and duties thereunder. However, the term "subcontractor" has no significance in the application of the Act, which was enacted under the Com merce Clause and which establishes duties for "employers" which are not de pendent for their application upon any contractual relationship with the Federal Government or upon any form of Federal financial assistance. 1910.13 Ship repairing. (a) Adoption and extension of estab lished safety and health standards for ship repairing. The standards prescribed by Part 1501 of this title and in effect on April 28, 1971, are adopted as occupa tional safety or health standards under section 6(a) of the Act and shall apply, according to the provisions thereof, to every employment and place of employ ment of every employee engaged in ship repair or a related employment. Each em ployer shall protect the employment and places of employment of each of his em ployees engaged in ship repair or a re lated employment, by complying with the appropriate standards prescribed by this paragraph. (b) Definitions. For purposes of this section: (1) "Ship repair means any repair of a vessel, including, but not restricted to, alterations, conversions, installations, cleaning, painting, and maintenance work; (2) "Related employment" means any employment performed as an incident to, or in conjunction with, ship repair work, including, but not restricted to, inspec tion, testing, and employment as a watch man; and (3) "Vessel" includes every descrip tion of watercraft or other artificial con trivance used, or capable of being used, as a means of transportation on water, including special purpose floating struc tures not primarily designed for, or used as a means of, transportation on water. 1910.14 Shipbuilding. (a) Adoption and extension of estab lished safety and health standards for shipbuilding. The standards prescribed by Part 1502 of this title and in effect on April 28, 1971, are adopted as occu pational safety or health standards under section 6(a) of the Act and shall apply, according to the provisions thereof, to every employment and place of employment of every employee en gaged in shipbuilding or a related em ployment. Each employer shall protect the employment and places of employ ment of each of his employees engaged in shipbuilding or a related employ ment, by complying with the appropriate standards prescribed by this paragraph. (b) Definitions. For purposes of this section: (1) "Shipbuilding" means the con struction of a vessel, including the in stallation of machinery and equipment; (2) "Related employment" means any employment performed as an incident to, or in conjunction with, shipbuilding work, including, but not restricted to, inspection, testing trials, and employ ment as a watchman: and (3) "Vessel" includes every description of watercraft or other artificial con trivance used, or capable of being used, as a means of transportation on water, including special purpose floating structures not primarily designed for, or used as a means of, transportation on water. 1910.15 Shipbreaking. (a) Adoption and extension of estab lished safety and health standards for shipbreaking. The standards prescribed by Part 1503 of this title and in effect on April 28, 1971, are adopted as occu pational safety or health standards under section 6(a) of the Act and shall apply, according to the provisions thereof, to every employment and place of employment of every employee en gaged in shipbreaking or a related em ployment. Each employer shall protect the employment and places of employ ment of each of his employees engaged in shipbreaking or a related employment, by complying with the appropriate stand ards prescribed by this paragraph. (b) Definitions. For purposes of this section: (1) "Shipbreaking" means any breaking down of a vessel's structure for the purpose of scrapping the vessel, in cluding the removal of gear, equipment, or any component part of a vessel; (2) "Related employment" means any employment performed as an inci dent to, or in conjunction with, shipbreaking work, including, but not re stricted to, inspection, survey, and em ployment as a watchman; and (3) "Vessel" includes every description of watercraft or other artificial contriv ance used, or capable of being used, as BFG30375 FB>ERAL REGISTER, VOL. 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 RULES AND REGULATIONS 22129 together laterally. The cross braces shall be of a length that will automatically uare and align vertical members so e erected scaffold is always plumb, square, and rigid. (3) Spacing. Spacing of panels or frames shall be consistent with the loads imposed. The frames shall be placed one on top of the other with coupling or stacking pins to provide proper vertical alignment of the legs. (4) Locking. Where uplift may occur, panels shall be locked together vertically by pins or other equivalent means. (5) Erection. Only the manufacturer of a scaffold or his qualified designated agent shall be permitted to erect or su pervise the erection of scaffolds exceed ing 50 feet in height above the base, un less such structure is approved in writing by a registered professional engineer, or erected in accordance with instructions furnished by the manufacturer. (c) Mobile tubular welded sectional folding scaffolds--(1) General. Units in cluding sectional stairway and sectional ladder scaffolds shall be designed to com ply with the requirements of paragraph (a) of this section. (2) Stairway. An integral stairway and work platform shall be incorporated into the structure of each sectional fold ing stairway scaffold. (3) Bracing. An integral set of pivot ing and hinged folding diagonal and hor izontal braces and a detachable work platform shall be incorporated into the structure of each sectional folding lad der scaffold. (4) Sectional folding stairway seafAds. Sectional folding stairway scaf folds shall be designed as medium duty scaffolds except for high clearance. These special base sections shall be designed as light duty scaffolds. When upper sec tional folding stairway scaffolds are used with a special high clearance base, the load capacity of the entire scaffold shall be reduced accordingly. The width of a sectional folding stairway scaffold shall not exceed feet. The maximum length of a sectional folding stairway scaffold shall not exceed 6 feet. (5) Sectional folding ladder scaffolds. Sectional folding ladder scaffolds shall be designed as light duty scaffolds in cluding special base (open end) sections which are designed for high clearance. For certain special applications the sixfoot (6') folding ladder scaffolds, except for special high clearance base sections, shall be designed for use as medium duty scaffolds. The width of a sectional folding ladder scaffold shall not exceed 4% feet. The maximum length of a sectional fold- ing ladder scaffold shall not exceed' 6 feet 6 inches for a six-foot (6') long unit, 8 feet 6 inches for an eight-foot (8') unit or 10 feet 6 inches for a ten-foot (10') long unit. (6) End frames. The end frames of sectional ladder and stairway scaffolds shall be designed so that the horizontal bearers provide supports for multiple planking levels. (7) Erection. Only the manufacturer jf the scaffold or his qualified designated agent shall be permitted to erect or supervise the erection of scaffolds ex ceeding 50 feet in height above the base, unless such structure is approved in writing by . a - licensed professional engineer, or erected in - accord ance with instructions furnished by the manufacturer. ... ' (d) Mobile tube, and coupler -scaf folds--(1) Design. Units shall be de signed to comply with the applicable requirements of paragraph (a) of this section. (2) Material. The material used for the couplers shall be of a structural type, such as a drop-forged steel, malleable iron or structural grade aluminum. The use of gray cast iron is prohibited. (3) Erection. Only the manufacturer of the scaffold or his qualified designated agent shall be permitted to erect or supervise the erection of scaffolds ex ceeding 50 feet in height above the base, unless such structure is approved in writing by a licensed professional engineer, or erected in accord ance with instructions furnished by the manufacturer. (e) Mobile work platforms--(1) De sign. Units shall be designed for the use intended and shall comply with the requirements of paragraph (a) of this section. (2) Base width. The minimum width of the base of mobile work platforms shall not be less than 20 inches. (3) Bracing. Adequate rigid diagonal bracing to vertical members shall be provided. (f) Mobile ladder stands. (1) Design. Units shall comply with applicable requirements of paragraph (a) of this section. (2) Base width. The minimum base width shall conform to paragraph (a) (3) (1) of this section. The maximum length of the base section shall be the total length of combined steps and top assembly, measured horizontally, plus five-eighths inch per step of rise. (3) Steps. Steps shall be uniformly spaced, and sloped, with a rise of not less than nine (9) inches, nor more than ten (10) inches, and a depth of not less seven (7) inches. The slope of the steps section shall be a minimum of fifty-five (55). degrees and a maximum of sixty (60) degrees measured from the horizontal. (4) Handrails, (i) Units having more than five (5) steps or 60 inches vertical height to the top step shall be equipped with handrails. (ii) Handrails shall be a minimum of 29 Inches high. Measurements shall be taken vertically from the center of the step. (5) Loading. The load (see paragraph (a)(2) (il) (a) of this section) shall be applied uniformly to a 3& inches wide area front to back at the center of the width span with a safety factor of four (4). 1910.30 Other working surfaces. (a) Dockboards (bridge plates'). (1) Portable and powered dockboards shall be strong enough, to carry, the load im posed on them. (2) Portable. dockboards shall be secured in position, either by being anchored or equipped with devices which wiff prevent their slipping. . (3) Powered dockboards be designed and constructed in accordance with Commercial Standard CS202-56 (1961> "industrial lifts and Hinged 'Loading Ramps published by the Uf>. Department of Commerce. (4) Handholds, or' other effective means, shall be provided on portable dockboards to permit safe handling. (5) Positive protection shall be pro vided to prevent railroad cars from being moved while dockboards or bridge plates are in position. - (b) Forging .machine area. (1) Ma chines shall be so located as to give (i) enough clearance between machines so that the movement of one operator will not interfere with the work of another, (ii) ample room for cleaning machine*; and handling the work, including mate rial and scrap. The arrangement of ma chines shall be such that operators wfll not stand in aisles. (2) Aisles shall be provided of suffi cient width to permit the free movement of employees bringing and removing material. This aisle space is to be in dependent of working and storage space and should be defined by marking. (3) Wood platforms used on the floor in front of machines shall be substan tially constructed. Cc) Fencer machinery. (1) of steam vats shall extend to a height of not less than 36 inches above the floor, working platform, or ground. (2> Large steam vats divided into sec tions shall be provided with substantial walkways between sections. Each walk way shall be provided with a standard handrail on each exposed side. These handrails may be removable, if neces- (3) Covers shall be removed only from that portion of steaming vats on which men are working and a portable railing shall be placed at this point to protect the operators. (4) workmen shall not ride or step on logs in steam vats. 1911X31 Sources of standards* The standards in this Subpart D are devised from the following sources: Standard S 1910.22(a)_______ 1910.22 (b) and <c>. 51910.33(d)_____ $ 1910.23 5 1910.24 5 1910.25 Source ANSI Z4.1-1968, Re quirements for Sani tation in Places of Employment. 41 era 50-204J). ANSI A58.1--1955, Mint- mum Design Loads In -Building and Other Structures. a ANSI A12.1-1967, SafetjAV Requirements fo&^ Floor and Wall Openj.s ings, Railings, ufiT Toeboards. ' ANSI A64.1-1968, Re-TH qulrements for PlndS Industrial Stairs." ^2 ANSI A14.1--1968, SafetyWA CodeWood LafodrdersP. ortabeletn^- FEDERAL REG1STER.VOL .37, NO-202--WEDNESDAY, OCTOBER ,18,-1972 . 22128 BUIES AND REGULATIONS Mnetal projections; The -nails shall: be the other end-of the bearer. where It is strength of the unit.-Nails shall be driven driven full length into the roof. When hitched again, leaving sufficient rope at full length. (All nails should be immedi rope . supports , are .used, -they *hftii : each end for. the supporting ties: ately withdrawn from dismantled consist of first-grade m&nila of .at <(S) Each workman-shall be protected -lumber.):- : v least three-quarter-inch diameter, or by a safety lifebelt attached to a lifeline. (v) All exposed surfaces shall be free equivalent^;:-r' The lifeline shall be securely attached to from sharp edges, burrs or other safety : (3) A substantial catch platform gbnii substantial members of the structure (not '.hazards. ;* - be installed below the working area of scaffold), onto securely: rigged lines, <3) Work levels, (i) The maximum roofs more than 20 feet from the ground which will safely suspend the workman work level height shall not exceed four to eaves with a slope greater than 3 in case of a fall. (4) times the miniTniim or least base inches in 12 inches without a. parapet. <v> Scope. This section establishes dimension of any mobile ladder stand or In width the platform *hi1 extend 2 safety requirements for the construction, scaffold. Where the basic mobile unit does feet beyond the projection of the eaves operation; maintenance, and use of scaf not meet this requirement, suitable out and shall be provided with a safety rail, folds used in the construction, alteration, rigger frames : shall- be employed to mid-rail, and toeboard. This provision demolition, and maintenance of build achieve this least base dimension, or pro shall not apply where employees en ings and structures. visions shall be made to guy or brace the gaged in work upon such roofs are pro tected by a safety belt attached to a lifeline. (t) Crawling boards or chicken lad ders. (1) Crawling boards shall be not 1910.29 Manually propelled " mobile ladder stands and scaffolds (lowers). <a) General requirements--(1) Appli cation. This section is Intended to pre unit against tipping. (ii) The minimum platform width for any work level shall not be less than 20 inches for mobile scaffolds (towers). Lad der stands shall have a minimum step less than 10 inches wide and 1 inch scribe rules and requirements for the width of 16 inches. thick, having cleats 1x1% inches. The design, construction, and use of mobile (hi) The supporting structure for the cleats shall be equal in length to-the work platforms (including ladder stands work level shall be rigidly braced, using width of the board and spaced at equal but notincluding aerial ladders) and rol adequate cross bracing or diagonal brac intervals not to exceed 24 inches. Nails ling (mobile) scaffolds (towers). This ing with rigid platforms at each work shall be driven through and clinched on standard is promulgated to aid in pro level. the underside. The crawling board shall viding for the safety of life, limb, and (Iv) The steps of ladder stands shall extend from the ridge pole to the eaves property, by establishing minimum be fabricated from slip resistant treads. when used in connection with roof con standards for structural design require (v) The work level platform of struction, repair, or maintenance. ments and for the use of mobile work scaffolds (towers) shall be of wood, (2) A firmly fastened lifeline of at platforms and towers. aluminum, or plywood planking, steel least three-quarter-inch rope 1 be (2) Working loads, (i) Work platforms or expanded metal, for the full width strung beside each crawling board for a and scaffolds shall be capable of carrying of the scaffold, except for necessary open handhold. - - ............ the design load under varying circum ings. Work platforms shall be secured (3) Crawling boards shall be secured stances depending upon the conditions of In place. All planking shall be 2-inch to the roof by means of adequate ridge use. Therefore, all parts and appurtances (nominal) scaffold grade minimum 1,500 hooks or equivalent effective means. necessary for their safe, and efficient f. (stress grade) construction grade lum <u) Float or ship scaffolds. (1) Float utilisation must be integral parts of the ber or equivalent. or ship scaffolds shall support not more deagn. (vl) All scaffold work levels 10 feet than three men and a few light tools, such fti) Specific design and construction or higher above the ground or floor shall as those needed for riveting, bolting, and requirements are not a part of this sec have a standard (4-inch nominal) welding. They shall be constructed in tion because of the wide variety of mate toeboard. accordance with subparagraphs (2) rials and design possibilities.' However, (vii) All work levels 10 feet or higher through (6) of this paragraph, unless the design shall be such as to produce a . above the ground or floor shall have a substitute designs and materials provide mobile ladder stand or- scaffold that will guardrail of 2- by 4-inch nominal or equivalent strength, stability, and safety. safety sustain the specified loads. The the equivalent - installed no less than (2) The platform shall be not less than material selected shall be of sufficient 36 inches or more than 42 inches high, 3 feet wide and 6 feet long, made of strength to meet the test requirements with a mid-rail, when required, of 1- by three-quarter-inch plywood, equivalent and shall be protected against corrosion 4-inch nominal lumber or equivalent. to American Plywood Association Grade or deterioration. - (viil) A climbing ladder or stairway B-B, Group I, Exterior. (a) The design working load of ladder shall be provided for proper access and (3) Under the platform, there shallbe stands shall be calculated on the basis of egress, and shall be affixed or built into two supporting bearers made from 2- x one or more 200-pound persons together the scaffold and so located that Its use 4-inch, or 1- x 10-inch rough, selected with 50 pounds of equipment each. will not have a tendency to tip the scaf lumber, or better. They shall be free of (b) The design load of .all scaffolds fold. A lauding platform shall be pro knots or other flaws and project 6 inches shall be calculated on the basis of: vided at intervals not to exceed 30 feet. beyond the platform on both sides. The Light--Designed and constructed to ouTy (4) Wheels or casters, (i) Wheels or ends of the platform shall extend about a working load ol 25 pounds per square foot. casters shall be properly designed for 6 inches beyond the outer edges of the MaHv-m--Designed and . constructed to . strength and dimensions to support four bearers. Each bearer shall be securely . fastened to the platform. (4) An edging of wood not less than % x 1% inches, or equivalent, shall be carry a working load at SO pounds per square foot. Heavy--Designed and constructed to carry a working load of 75 pounds per square foot. (4) times the design working load. (li> All scaffold casters shall be pro vided with a positive wheel and/or swivel lock to prevent movement. Ladder stands placed around all sides of the platform All ladder stands and scaffolds shall be shall have at least two (2) of the four (4) to prevent tools from rosing off. capable of supporting at least four times casters and shall be of the swivel type. (5) Supporting ropes Shall be 1-inch the design working load. (iii) ' Where leveling of the elevated diameter manila rope or equivalent, free . Oh) The materials used in mobile lad work platform is required, screw jacks . from deterioration, riiemWi damage, der stands and scaffolds shall be of stand or other suitable means for adjusting the .flaws/or other imperfections. Rope con ard manufacture and conform to stand-, height shall be provided in the base sec nections shall-be such that the platform ard specifications, of strength, dimen tion of each mobile unit, c&nnotshiftar slip* If two ropes are used sions, and weights, and shall be selected (b) Mobile tubular welded frame scaf with each float, they should be arranged to safely support the design working load. folds--tl ) General. Units shall be de - so as: to provide fbur ends which are to . (iv> Nails, bolts, or . other fasteners signed to comply with the requirements be securely^astenedto an overhead sup used in the construriion of ladders; scaf of paragraph (a) of this section. . port. Each of the tivo'supporting'ropes folds, and towers shall be of: adequate .*: - (2) Bracing. Scaffolds shall be prop- shall <be hitchetf?around one end of a size and in sufficient numbers at each erly braced by cross braces and/or diag- bearer and pass under the platforms to - connectionto. develop, the: designed : onal braces for securing vertical members : FEDERAL REGISTB, VOL 37,- NO.- 202--WEDNESDAY; .OCTOBER 18, 1972 -RULES AND REGULATIONS '22105 a means of transportation cm water, in 1910;18:iiChanges in established Fed- or other guards that meets the require cluding-special purpose-floating struc - era! standards; ments of 5 1910.23. tures not primarily designed for, or used as a means of, transportation on water. 1910.16 Longshoring. <a) Adoption and extension of estab lished safety and health standards for longshoring. The standards prescribed by Part 1504 of this title and in effect on April 28, 1971, are . adopted as occupa tional safety or health standards under section 6(a) of the Act and shall apply, according to. the provisions thereof, to every employment and place of employ ment of every employee engaged in longshoring operations or a related employ ment. Each employer shall protect the Whenever an occupational safety and health standard' adopted and incorpo rated by reference in this Subpart B is changed pursuant..to sectiori;6(b) of the ' Act and the statute under which the standard was originally promulgated, and In accordance with Part 1911 of this chapter, the standard shall be deemed changed forpurposes of that statute and this Subpart B, and shall apply under this Subpart B. For the purposes of this section,; a change in a standard includes any amendment, addition, or repeal, in whole or in part, of any standard. 1910.19 Asbestos dust. , . ; :(8) Stair railing. A vertical barrier erected along exposed sides of a stairway . to prevent falls of persons.:'.-;:.','-,. (9) Toeboard.: A vertical .barrier . at floor level erected along .exposed edges aTa floar opening, wall opening, plat form. runway, or ramp to prevent falls of materials. (10> Wall hole. An opening less than 30 inches but more than l.inch high, of unrestricted width, in any wall or parti-. . tion; such as a ventilation hole or drain age scupper. (ID WaU opening. An opening at least 30 tnches high and 18 inches wide, in any wan or partition, through which persons employment- and places of employment of each of his employees engaged in a longshoring operation or a related em ployment, by complying with the appro priate standards prescribed by this paragraph. (b) Definitions. For purposes of this section: (1) "Longshoring operation" means the loading, unloading, moving, or han dling of, cargo, ship's stores, gear, etc., into, in, on, or out of any vessel; (2) "Related employment" means any employment performed as an incident to Section 1910.93a shall apply to the ex posure of every employee to asbestos dust in every employment and place of employment covered by 51910.12, 1910.13,11910.14, S 1910.15, or 1910.16, in lieu of any different standard on ex posure to asbestos dust which would otherwise be applicable by virtue of any of those sections. Subpari C--[Reserved] . Subport D---Walking-Working Surfaces may fall; such as a yard-arm doorway or chute opening. (b> As used in 1910.24, unless the context requires otherwise, fixed indus trial stair terms shall have the meaning ascribed in this paragraph. (1) Handrail. A single bar or pipe sup ported on brackets from a wall or parti tion to provide a continuous handhold for persons using a stair. (2) Nose, nosing. That portion of a tread projecting beyond the face of the riser immediately below. (3) Open riser. The air space between or in conjunction with, longshoring oper ations including, but not restricted to, securing cargo, rigging, and employment as a porter, checker, or watchman; and (3) "Vessel" includes every descrip- tion of watercraft or other artificial con trivance used, or capable of being used, as a means of transportation on water, in cluding, special purpose floating struc tures not primarily designed for, or used as a means of, transportation on water, 1910.17 Effective dates. . (a) Except as provided in paragraphs (b) and (c) of this section, the stand ards prescribed in this Subpart B shall .be effective on August 27, 1971. (b) (1) To the extent that the stand ards prescribed in 51910.12 apply to light residential construction or to other construction work, as defined in S 1910.12(b), which is not subject to the construction safety standards published in Part 1926 of this title, their applica tion is delayed until September 27,1971. (2) For the purpose of subparagraph (1) of this paragraph, "light residential construction" is limited to the construc tion of homes and apartments which do not exceed three stories in height, and which have no elevator. -. (c) Except as provided in paragraph (b) of this section, whenever any em ployment or place of employment Is, or becomes, subject to any safety and health standard prescribed in Fart 1915, 1910.21 Definitions. () As used in 11910.23, unless the ' context requires otherwise, floor and wall opening, railing and toe board terms the treads of stairways without upright members (risers). - (4) Platform. An extended step or landing breaking a continuous run of shall have the meanings ascribed in this paragraph.-''. (1) Floor hole. An opening measuring less than 12 inches but more than 1 inch In Its least dimension, in any floor, plat - : (5) Bailing. A vertical barrier erected along exposed sides of stairways and platforms to prevent falls of persons. ; The top member of railing usually serves fig a. BunHrail : form, pavement, or yard, through which materials but not persons may fall; such as a belt' hole, pipe opening, or slot opening. ; (2) Floor opening. An opening meas uring 12 inches or more in its least di mension, in any floor, platform, pave ment, or yard, through which persons may- fall; such as a hatchway, stair or ladder opening, pit, or large manhole. Floor openings occupied' by elevators, dumb waiters, conveyors, machinery, or containers are excluded from this sub part. . (3) Handrail. A single bar or pipe sup ported, on brackets from a wall or par tition, as on a stairway or ramp, to furnish persons with a handhold in case of tripping.; (4) Platform. A working space for per sons,' elevated above the surrounding (6) Rise. The vertical distance from the top of a tread to the top of the next higher tread. ; ........ : . Cl) Riser. The upright member of a step situated at the back of a lower tread and. near the leading edge, of the next higher bread.................... (8) Stairs, stairway, A series of steps leading &om one level or floor to an other, or. leading to platforms, pits, boiler rooms, crossovers, or around ma chinery, tanks, and other equipment that are used more or less continuously or routinely by employees, or only occasion ally by specific individuals. A series of steps and landing* having three or more risers constitutes stairs or' stairway. <9)TreacL The horizontal member of asteP. . : (10> Tread run. The horizontal dis- floor or ground; such as a balcony or -tance from the leading edge of a tread platform for the operation of machinery to the leading edge of an adjacent tread. and equipment. : U1) Tread width. The horizontal dis- (5) Runway. A passageway for per . tance from front to back of tread in sons, elevated above the surrounding cluding nosing when used. ... 1916,1917, 1918, or 1926 of this title on floor or ground level,' such as a footwalk Cc) As used in 1910.25, unless the a date before August 27, 1971, by virtue along shafting or a walkway between > context requires otherwise, > portable of the Construction Safety Act or the buildings. ; ` : wood ladders terms shall have the mean Longshoremen's and Harbor Workers* () Standard failing. 'A vertical bar ings ascribed in this paragraph. Compensation Act, that occupational rier erected along exposed edges of a (1)-Ladders. A ladder is an appliance safety and health standard as incorpo floor opening; wall opening, ramp, plat '-'usually' consisting of--two side rails rated by reference in this - subpart form, or runway to prevent falls" of J(fined at regular intervals by crosspieces 'hall also become - effective under, the persons. \/:- , called, stepe^rungsmpr cleats, on, which TUliams-Steiger Occiqjational Safety (7) Standard strength and construc i ar;person,imayr step,r ta: ascending or and Health Act of 1970 on that date; " ? - tion. Any construction Of railings, covers. descending^-hdiffii: M.r-v-'. ,v v.*; z-4 . .. eoo&sefrz FEDERAL REGISTER, VOC"37, N<).v202--WEDNESDAY, OCTOBER T^1972 BFG30376 J 22106 RULES AND REGULATIONS (2) Stepladder. A stepladder is a selfsupporting portable ladder* nonadjustable in length, having flat steps and a lunged back. Its size is designated by the overall length of the ladder measured along the front edge of the side rails. (3) Single ladder. A single ladder is a non-self-supporting portable ladder, nonadjustable in length, consisting of but one section. Its size is designated by the overall length of the side rail. (4) Extension ladder. An extension ladder is a non-self-supporting portable ladder adjustable in length. It consists of two or more sections traveling in guides or brackets so arranged as to per mit length adjustment. Its size is desig nated by the sum of the lengths of the sections measured along the side rails. (5) Sectional ladder. A sectional ladder is a non-self-supporting portable ladder, nonadjustable in length, consisting of two or more sections of ladder so constructed that the sections may be combined to function as a single ladder. Its size is designated by the overall length of the assembled sections. <6> Trestle ladder. A trestle ladder is a self-supporting portable ladder, nonad justable in length, consisting of two sec tions hinged at the top to form equal angles with the base. The size is desig nated by the length of the side rails measured along the front edge. (7) .Extension trestle ladder. An exten sion trestle ladder is a self-supporting portable ladder, adjustable in length, consisting of a trestle ladder base and a vertically adjustable single ladder, with suitable means for locking the ladders to gether. The size is designated by the length of the trestle ladder base. (8) Special-purpose ladder. A specialpurpose ladder is a portable ladder which represents either a modification or a combination of design or construction features in one of the general-purpose types of ladders previously define^ in or der to adapt the ladder to special or specific uses. (9) Trolley ladder. A trolley ladder is a semifixed ladder, nonadjustable in length, supported by attachments to an overhead track, the plane of the ladder being at right angles to the plane of motion. (10) Side-roHfnp ladder. A side-roll ing ladder Is a semifixed ladder, nonad justable in length, supported by attach ments to a guide rail, which is generally fastened to shelving, the plane of the ladder being also its plane of motion. (11) Wood characteristics. Wood char acteristics are distinguishing features which by their extent and number deter mine the quality of a piece of wood. (12) Wood irregularities. Wood irregu larities are natural characteristics in or on wood that may lower its durability, strength, or utility. (13) Cross grain. Cross grain (slope of grain) is a deviation of the fiber direc tion from a line parallel to the sides of the piece. (14) Knot. A knot is a branch or limb, imbedded in the tree and cut through in the process of lumber manufacture, clas sified according to size, quality* and oc currence. The size of the knot is determined as the average diameter on the surface of the piece. (15) Pitch and bark Pockets. A pitch pocket is an opening extending parallel to the annual growth rings containing, or that has contained, pitch, either solid or liquid. A bark pocket is an opening between annual growth rings that con tains bark. (16) Shake. A shake is a separation along the grain, most of which occurs between the rings of annual growth. (17) Check. A check is a lengthwise separation of the wood, most of which occurs across the rings of annual growth. (18) Wane. Wane is bark, or the lack of wood from any cause, on the comer of a piece. (19) Decay. Decay is disintegration of wood substance due to action of wooddestroying fungi. It is also known as dote and rot. (20) Compression failure. A compres sion failure is a deformation (buckling) of the fibers due to excessive compres sion along the grain. (21) Compression wood. Compression wood is an aberrant (abnormal) and highly variable type of wood structure occurring in softwood species. The wood commonly has density somewhat higher than does normal wood, but somewhat lower stiffness and tensile strength for its weight in addition to high longitudi nal shrinkage. (22) Low density. Low-density wood is that which is exceptionally light in weight and usually deficient in strength properties for the species. (d) As used in 9 1910.26, unless the context requires otherwise, portable metal ladder terms shall have the mean ings ascribed in this paragraph. (1) Ladder. A ladder is an appliance usually consisting of two side rails joined at regular intervals by crosspieces called steps, rungs, or cleats, on which a per son may step in ascending or descending. (2) Step ladder. A step ladder is a selfsupporting portable ladder, nonadjusta ble in length, having fiat steps and a hinged back. Its size is designated by the overall length of the ladder measured along the front edge of the side rails. (3) Single ladder,. A single ladder is a non-self-supporting portable ladder, nonadjustable in length, consisting of but one section. Its size is designated by the overall length of the side rail. (4) Extension ladder. An extension ladder is a non-self-supportmg portable ladder adjustable in length. It consists of two or more sections traveling in guides or brackets so arranged as to permit length adjustment. Its size is des ignated by the sum of the lengths of the sections measured along the side rails. (5> Platform ladder. A self-supporting ladder of fixed size with a platform pro vided at the working level. The size is determined by the distance along the front rail from the platform to the base of the ladder. (6) Sectional ladder. A sectional lad der is a nun-self-supporting portable ladder, non-adjustable in length, con sisting of two or more sections so con structed that the sections may be com bined to-function as. a single ladder. Its size is designated by the overall length of the assembled sections. (7) Trestle ladder. A trestle ladder is a self-supporting portable ladder, nonadjustable in length, consisting of two sections, hinged at the top to form equal angles with the base. The size is des ignated by the length of the side rails measured along the front edge. (8) Extension trestle ladder. An ex tension trestle ladder is a self-supporting portable ladder, adjustable in length, consisting of a trestle ladder base and a vertically adjustable single ladder, with suitable means for locking the ladders together. The size is designated by the length of the trestle ladder base. (9) Special-purpose ladder. A specialpurpose ladder is a portable ladder which represents either a modification or a combination of design or construction features in one of the general-purpose types of ladders previously defined, in order to adapt the ladder to special or specific uses. (e) As used in 9 1910.27, unless the context requires otherwise, fixed ladder terms shall have the meanings ascribed in this paragraph. (1) Ladder. A ladder is an appliance usually consisting of two side rails joined at regular intervals by crosspieces called steps, rungs, or cleats, on which a person may step in ascending or descending. <2) Fixed ladder. A fixed ladder is a ladder permanently attached to a struc ture, building, or equipment. (3) Individual-rung ladder. An indi vidual-rung ladder is a fixed ladder each rung of which is individually attached to a structure, building, or equipment. (4) Rail ladder. A rail ladder is a fixed ladder consisting of side rails joined at regular intervals by rungs or cleats and fastened in full length or in sections to a building, structure, or equipment. (5) Bailings. A railing is any one or a combination of those railings constructed in accordance with 1910.23. A standard railing is a vertical barrier erected along exposed edges of floor openings, wall openings, ramps, platforms, and runways to prevent fails of persons. (6) Pitch. Pitch is the included angle between the horizontal and the ladder, measured cm the opposite side of the ladder from the climbing side. (7) Fastenings. A fastening is a device to attach a ladder to a structure, build ing, or equipment. (8) Rungs. Rungs are ladder cross pieces of circular or oval cross-section on which a person may step in ascend ing or descending. (9) Cleats. Cleats are ladder cross pieces of rectangular cross-section placed on edge on which a person may step in ascending or descending. (10) Steps. Steps are the flat cross pieces of a ladder on which a person may step in ascending or descending. (ID Cage. A cage is a guard that may be referred to as a cage or basket guard which is an enclosure that is fastened to the side rails of the fixed ladder or to the structure to encircle the climbing BFG30377 FEDERAL REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER 16,1972 RULES AND REGULATIONS 22127 (5) Platform planks shall be at least knot or by & round turn and one-half both types of scaffold designed to sustain 2- by 9-inch nominal size. The ends of the hitch. a uniform distributed working load up mtoi shall overlap the bearers of the (4) The platform span between the to heavy duty scaffold loads with a safety lares and each plank shall be sup needle beams shall not exceed 8 feet factor of four. ported by not less than three squares. when using 2-inch scaffold plank. For (5) When a hanging scaffold is sup (6) Bricklayers' square scaffolds shall spans greater than 8 feet, platforms shall ported by means of- wire rope, such wire not exceed three tiers in height and shall be designed based on design require rope shall be wrapped at least twice be so constructed and arranged that one ments for the special span. The over around the supporting members and square shall rest directly above the other. hang of each end of the platform planks twice around the bearers of the scaffold, The upper tiers shall stand on a con shall be not less than 1 foot and not with each end of the wire rope secured tinuous row of planks laid across the next more than 18 inches. by at least three standard wire-rope lower tier and be nailed down or other (5) When one needle beam is higher clips. wise secured to prevent displacement. than the other or when the platform is (6) AH overhead supporting members (7) Scaffolds shall be level and set not level the platform shall be secured shall be inspected and checked for upon a firm foundation. (m) Horse scaffolds. against slipping. strength before the scaffold is erected. (6) All unattached tools, bolts, and (7) Guardrails not less than 2 by 4 (1) Horse scaffolds shall not be con nuts used on needle beam scaffolds shall inches or the equivalent and not less structed or arranged more than two tiers be kept in suitable containers. than 36 inches or more than 42 inrh^a or 10 feet in height. (7) One end of a needle beam scaf high, with a mid-rail, when required, of (2) The members of the horses shall be fold may be supported by a permanent 1- by 4-inch lumber or equivalent, not less than those specified in Table structural member conforming to para toeboards, shall be installed at all open D-19. graph (a) (4) and (8) of this section. sides on all scaffolds more than 10 feet (3) Horses shall be spaced not more (8) Each man working on a needle above the ground or floor. Toeboards than feet for medium duty and not beam scaffold 20 feet or more above the shall be a minimum of 4 inches in height. more than 8 feet for light duty. ground or floor and working with both Wire mesh shall be installed in accord (4) When arranged in tiers, each horse hands, shall be protected by a safety life ance with paragraph (a) (17) of this shall be placed directly over the horse in belt attached to a lifeline. The lifeline section. the tier below. shall be securely attached to substantial (q) Ladder-jack scaffolds. (1) All (5) On all scaffolds arranged in tiers, members of the structure (not scaffold), ladder-jack scaffolds shall be limited the legs shall be nailed down to the or to securely rigged lines, which will to light duty and shall not exceed a planks to prevent displacement or thrust and each tier shall be substantially cross braced. safely suspend the workman in case of a fall. (0) Plasterers', decorators', and large height of 20 feet above the floor or ground. (2) All ladders used in connection Table E>-19--MDninni Dimensions for Horse Scaffold Members area scaffolds. (1) Plasterers', decora with ladder-jack scaffolds shall be tors', lathers', and ceiling workers' in heavy-duty ladders and shall be designed Members: Horizontal members or bear ers ------------------------------------------ jegs-------------------------------------Longitudinal brace between legs Gusset brace at top of legs.. Half diagonal braces.:_______ Dimensions (inches) 3 by 4. 1)4 by 4)4- 1 by 6. I by 8. 1)4 by 4%. side scaffolds shall be constructed in ac cordance with the general requirements set forth for independent wood pole scaffolds. (2) Guardrails not less than 2 by 4 inches or the equivalent and not less than 36 inches or more t.hn 42 inches high, with a mid-rail, when required, of 1- by 4-inch lumber or equivalent, and and constructed in accordance with 9 1910.25 and 9 1910.26. (3) The ladder jack shall be so de signed and constructed that it will bear on the side rails in addition to the lad der rungs, or if bearing on rungs only, the bearing area shall be at least 10 inches on each rung. (4) Ladders used in conjunction with (6) Horses or parts which have become toeboards, shall be installed at all open ladder jacks shall be so placed, fastened, weak or defective shall not be used. sides on all scaffolds more than 10 feet held, or equipped with devices so as to (7) Guardrails not less than 2 by 4 above the ground or floor. Toeboards prevent dipping. inches or the equivalent and not less than shall be a minimum of 4 inches in (5> ' The wood platform pfanire shall be 36 inches or more than 42 inches high height. Wire mesh shall be installed in not less than 2 inches nominal in thick with a mid-rail, when required, of 1- by accordance with paragraph (a) (17) of ness. Both metal and wood platform 4-inch lumber or equivalent and tqe- this section. planks shall overlap the bearing surface boards, shall be installed at all open (3) All platform planks shall be laid not less than 12 inches. The span be sides on all scaffolds more than 10 feet with the edges close together. tween supports for wood shall not exceed above the ground or floor. Toeboards (4) When independent pole scaffold 8 feet. Platform width shall be not less shall be a minimum of 4 inches in height. platforms are erected in sections, such than 18 inches. Wire mesh shall be installed in accord sections shall be provided with connect (6) Not more than two persons shpii ance with paragraph (a) (17) of this ing runways equipped with substantial occupy any given 8 feet of any ladder- section. guardrails. jack scaffold at any one time. (n> Needle beam scaffold. (1) Wood (p) Interior hung scaffolds. (1) An in (r) Window-jack scaffolds. (1) Win needle beams shall be in accordance with terior hung scaffold should be hung or dow-jack scaffolds shall be used only paragraph (a) (5) and (9) of tills sec suspended from the roof structure or for the purpose of working at the win tion, and shall be not less than 4 by 6 substantial ceiling beams. dow opening through which the jack is inches in size, with the greater dimen (2) The suspended steel wire rope placed. sion placed in a vertical direction. Metal shall conform to paragraph (a) (22) of (2) Window jacks shall not be used beams or the equivalent conforming to this section. Wire may be used provid to support planks placed between one paragraph (a) (4) and (8) of this section ing the strength requirements of para window jack and another or for other may be used. graph (a) (22) of this section are met. elements of scaffolding. (2) Hopes or hangers shall be pro-, (3) For hanging wood scaffolds, the (3) Window-jack scaffolds shau be vided for supports. The span between following minimum nominal size mate provided with suitable guardrails untom supports on the needle beam shall hot rial is recommended: safety belts with lifelines are attached exceed 10 feet feu 4- lor 6-inch timbers. Rope supports shall be equivalent in strength to 1-inch diameter first-grade (1) Supporting bearers 2 by 9 inches on edge. rii) Planking 2 by 9 Inches or 2 by 10 and provided feu- the workman. Windowjack scaffolds shall be used by one man only. manila rope. ' inches, with maximum span 7 feet for (s) Roofing brackets(1) Roofing (3) The ropes shall be attached to the heavy duty and 10 feet for light duty brackets shall be constructed to fit the edle beams hr a scaffold hitch or a - or medium duty. pitch of the roof. roperly made eye splice. The loose end ~ <4) Steel tube and coupler members . (2) Brackets shall be secured in place of the rope shall be tied by a bowline may be used for hanging scaffolds with hy nniHr.fr iq addition to the pointed FEDERAL REGISTER, VOL.37, NO. 202--WEDNESDAY, OCTOBE 18, 1972 fcTOSSCbZ 22126 RULES AND REGULATIONS Table D-17--Schedule fob Laddxe-Ttp* Platforms properly spliced %-inch diameter first- Length of platform (feet) grade manila rope. (6) The roof irons, hooks, or the ob 12 144 16 16420 22424 28*30 ject to which the tackle is anchored shall be securely installed. Tiebacks when used Side stringers, minimum cross section (finished sizes): At ends (in.)................................................................... 1Kx2K lK*8k 1K*3 1Ki3 IXtSH At middle (In.).__ ________ ______________ ........ 1Ks3K 1Ki3K 1Ki4 1Ki4K lKx6 Reinforcing strip (minimum).................. A KiK-ta. steel reinforcing strip or Its equivalent shall be attached to the side or underside full length. Bungs................................................................................... Bongs shall be l>f4n. minimum, diameter with at least %-ta. diameter tenons, and the miiimuia spacing shall he 12 in. center to center. 'Tlerodsr Number (minimum)_____________ _____ ________ _ 3 4 4 5 6 Diameter (minimum).............. ...................... Kto. Kin. Kin. Kin. Kin. Flooring, minimum finished size (in.)...................... KiZK Hi2K }4x2H Hi^ shall be installed at right angles to the face of the building and securely fastened to a chimney. (k) Carpenters' bracket scaffolds. (1) The brackets shall consist of a triangular wood frame not less than 2 by 3 inches in cross section, or of metal of equivalent strength. Each member shall be properly fitted and securely joined. (2) Each bracket shall be attached to (h) Stone setters' adjustable multi listed by Underwriters' Laboratories or the structure by means of one of the ple-point suspension scaffolds. (1) The Factory Mutual Engineering Corp. : foDowing: scaffold shall be capable of sustaining (2) The power units may be either (i) A bolt no less than five-eighths a working load of 25 pounds per square electrically or air motor driven. inch in diameter which shall extend foot and shall not be overloaded. Scaf (3) All power-operated gears and through the inside of the building wall. folds shall not be used for storage of brakes shall be enclosed. (ii) A metal stud attachment device. stone or other heavy materials. (4) In addition to the normal operat <iii) Welding to steel tanks. (2) The hoisting machine and its ing brake, all-power driven units must (iv) Hooking over a well-secured and supports shall be of a type tested and have an emergency brake which engages adequately strong supporting member. listed by Underwriters' Laboratories or Factory Mutual Engineering Corp. (3) The platform shall be securely fastened to the hangers by U-bolts or automatically when the normal speed of descent is exceeded. (5) Guards, mid-rails, and toeboards shall completely enclose the cage or bas The brackets shall be spaced no more than 10 feet apart. (3) No more than two persons shall occupy any given 10 feet of a bracket other equivalent means. ket. Guardrails shall be no less than scaffold at' any one time. Tools and mate (4) The scaffold unit shall be sus 2 by 4 inches or the equivalent installed rials shall not exceed 75 pounds in addi pended from metal outriggers, iron no less than 36 inches nor more than 42 tion to the occupancy. brackets, wire rope slings, or iron hooks which will safely support the maximum intended load. (5) Outriggers when used shall be set with their webs in a vertical posi tion, securely anchored to the building inches above the platform. Mid-rails shall be 1 by 6 inches or the equivalent, installed equidistant between the guard rail and the platform. Toeboards shall be a-minimum of 4 inches in height. ... (6) The hoisting machines, cables, and (4) The platform shall consist of not less than two 2- by 9-inch nominal size planks extending not more than 18 inches or less than 6 inches beyond each end support. or structure and provided with stop equipment shall be regularly serviced (5) Guardrails not less than 2 by 4 bolts at each end. and inspected after each installation and Inches or the equivalent and not less (6) The scaffold shall be supported every 30 days thereafter. than 36 inches or more than 42 inches by wire rope conforming with paragraph (7) .. The units may be combined to high, with a mid-rail, when required, of (a> (22) of this section, suspended from form a two-point suspension scaffold. 1- by 4-inch lumber or equivalent, and overhead supports. Such scaffold shall comply with para toeboards, shall be installed at all open (7) The free ends of the suspension graph (g) of this section. sides on all scaffolds more than 10 feet wire ropes shall be equipped with proper size thimbles, seemed by splicing or other equivalent means. The running ends shall be securely attached to the hoisting drum and at least four turns of rope shall remain on the drum at all times. (3) Guardrails not less than 2 by 4 (8) The supporting cable shall be straight for its entire length, and the operator shall not sway the basket and fix the cable to any Intermediate points to change his original path of travel. (9) Equipment shall be maintained and used in accordance with the manu facturers' instructions. above the ground or floor. Toeboards shall be a minimum of 4 inches in height. Wire mesh shall be Installed in accord ance with paragraph (a) (17) of this section. (l) Bricklayers' square scaffolds. (1) The squares shall not exceed 5 feet in width and 5 feet in height. Inches or the equivalent and not less than 36 inches or more than 42 inches high, with a mid-rail, when required, of 1- by 4-inch lumber or equivalent, and toeboards, shall be installed at all open sides on all scaffolds more than 10 feet above the ground or floor. Toeboards shall be a minimum of 4 inches in height. Wire mesh shaft be installed in accord ance with paragraph <a>(17) of this section. (9) When two or more scaffolds are used on a building or structure they shall (10) Suspension methods shall con form to applicable provisions of para graphs (f) and (g) of this section. (j) Boatswain's chairs. (1) The chair seat shall be not less than 12 by 24 Inches, and of 1-inch thickness. The seat shall be reinforced on the underside to prevent the board from splitting. (2) The two fiber rope seat slings shall be of %-inch diameter, reeved through the four seat holes so as to cross each other on the underside of the seat. (2) Members shall be not less than those specified in Table D-18. (3) The squares shall be reinforced on both sides of each corner with 1- by 6-inch gusset pieces. They shall also have braces 1 by 8 inches on both sides run ning from center to center of each mem ber, or other means to secure equivalent strength and rigidity. (4) The squares shall be set not more than 5 feet apart for medium duty scaf folds, and not more than 8 feet apart for light duty scaffolds. Bracing 1x8 inches, not be bridged one to the other but shall be maintained at even height with plat forms butting closely. .(10) Each scaffold shall be installed or (3) Seat slings shall be of at least %inch wire rope when a workman is con ducting a heat producing process such as gas or arc welding. extending from the bottom of each square to the top of the next square, shall be provided on both front and rear sides of the scaffold. relocated in accordance with designs and instructions of a registered professional engineer, turd such installation or reloca tion shall be. supervised by a competent designated person. - (1) Single-point adjustable suspension (4) The workman shall be protected by a safety life belt attached to a lifeline. The lifeline shall be securely attached to substantial members of the structure (not scaffold), or to securely rigged lines, which will safely suspend the worker in Table D-18--Minimum Dimensions too. Bricklayers' Squabs Scaffold Members Dimensions Members: (inches) Bearers or horizontal members___ 2 by 6. Legs._______ 2 by 6. scaffolds. (1) The scaffolding, including case of a fall. Braces at corners--------------------------- 1 by 6. power units or manually operated (5) The tackle shall consist of correct Braces diagonally from center winches, shall be of a type tested and size ball bearing or bushed blocks and frame------------------------------------------- 1 by 8. FEDERAL REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER IB, 1972 RULES AND REGULATIONS i22X07 space of the ladder for the safety of the (11) Heavy duty scaffold: A scaffold i(29) Staple pole scaffold. Platforms person who must climb the ladder. designed and constructed ~ to " carry : a resting on putlogs or crossbeams, the (12) Well. A well is a permanent com working load not to exceed 75 pounds per outside ends of which are supported on plete enclosure around a fixed ladder, square foot. ; ledgers secured to a single row of posts which is attached to the walls of the (12) Horse scaffold. A. scaffold for or.uprights and the inner ends of which well. Proper clearances for a well will light or medium duty, composed of horses are supported on or in a wall. give the person who must climb the lad supporting a work platform.. (30) Stone setters' adjustable multiple- der the same protection as a cage. (13) Interior hung scaffold. A scaffold point suspension scaffold. A swinging- (13) Ladder safety device. A ladder suspended from the ceiling or roof type scaffold having a platform sup safety device is any device, other than a structure. ported by hangers suspended at four cage or well, designed to eliminate or re (14) Ladder jack scaffold. A light duty points so as to permit the raising or duce the possibility of accidental falls scaffold supported by brackets attached lowering of the platform to the desired and which may incorporate such fea to ladders. working position by the use of hoisting tures as life belts, friction brakes, and (15) Ledger (stringer). A horizontal machines. sliding attachments. scaffold member which extends from post (31) Toe board. A barrier secured 1 (14) Grab bars. Grab bars are in to post and which supports the putlogs along the sides and ends of a platform, dividual handholds placed adjacent to or bearer forming a tie between the posts. to guard against the falling of material. or as an extension above ladders for (16) Light duty scaffold. A scaffold de (32) Tube and coupler scaffold. An as the purpose of providing access beyond signed and constructed to carry a work sembly consisting of tubing which serves the limits of the ladder. ing load not to exceed 25 pounds per as posts, bearers, braces, ties, and run (15) Through ladder. A through lad square foot. ners, a base supporting the posts; and der is one from which a man. getting off (17) Manually propelled mobile scaf special couplers which serve to connect at the top must step through the ladder fold. A portable rolling scaffold sup the uprights and to join the various in order to reach the landing. ported by casters. members. (16) Side-step ladder. A side-step lad (18) Masons' adjustable multiple- (33) Tubular welded frame scaffold. der is one from which a man getting off point suspension scaffold. A scaffold A sectional, panel, or frame metal scaf at the top must step sideways from the having a continuous platform supported fold substantially, built UP of prefabri ladder in order to reach the landing. by bearers suspended by wire rope from cated welded sections which consist of (f) As used in 5 1910.28, unless the overhead supports, so arranged and op posts and horizontal bearer with inter context requires otherwise, scaffolding erated as to permit the raising or lower mediate members. Panels or frames shall terms shall have the meaning ascribed ing of the platform to desired working be braced with diagonal or cross braces in this paragraph. positions. (34) Two-point suspension scaffold (1) Bearer. A horizontal member of a (19) Maximum intended load. The (swinging scaffold). A scaffold, the plat scaffold upon which the platform rests total of all loads including the working form of which is supported by hangers and which may be supported by ledgers. load, the weight of the scaffold, and such (stirrups) at two points, suspended from (2) Boatswain's chair. A seat support other loads as may be . reasonably overhead supports so as to permit the ed by slings attached to a suspended anticipated. raising or lowering of the platform to rope, designed to accommodate one (20) Medium duty scaffold. A scaffold the desired working position by tackle or workman in a sitting position. designed and constructed to carry a hoisting wiftfihlnftg (3) Brace. A tie that holds one scaf working load not to exceed 50 pounds per ; (35) Window jack scaffold. A scaffold, fold member in a fixed position with re square foot. the platform of which is supported by a spect to another member. (21) Mid-rail. A rail approximately bracket or jack which projects through (4) Bricklayers' square scaffold. A midway between the guardrail and plat a window opening. . scaffold composed of framed wood form, used when required, and secured (36) Working load. Load imposed.by squares which support a platform limit to the uprights erected along the exposed men, materials, and equipment. ed to light and medium duty. sides and ends of platforms. (g) As used in 5 1910.29. unless the (5) Carpenters' bracket scaffold. A (22) Needle beam scaffold. A light duty context requires otherwise, manually scaffold consisting of wood or metal scaffold consisting of needle beams sup propelled mobile ladder stand and scaf brackets supporting a platform. (6) Coupler. A device for locking to gether the component parts of a tubular metal scaffold. The material used for the couplers ahull be of a structural type, such as a drop-forged steel, malleable iron, or structural grade aluminum. The use of gray cast iron is prohibited. (7) Crawling board or chicken ladder. A plank with cleats spaced and secured at equal Intervals, for use by a worker on roofs, not designed to carry any material. (8) Double pole or independent pole scaffold. A-scaffold supported from the base by a double row of uprights, inde pendent of support from the walls and constructed of uprights, ledgers, horizon tal platform bearers, and diagonal brac ing. porting a platform. (23) Outrigger scaffold. A scaffold supported by outriggers or thrustouts projecting beyond the wall or face of the building or structure, the inboard ends of which are secured inside of such a building or structure. (24) Putlog. A scaffold member upon which the platform rests. -. (25) Roofing bracket. A bracket used in sloped roof construction, having pro visions for fastening to the root or sup ported by ropes fastened over the ridge and. secured to some suitable object. (26) Runner. The lengthwise horizon tal bracing or bearing members or both. (27) Scaffold. Any temporary ele vated platform and its supporting struc fold (tower) terms shall have the mean ing ascribed in this paragraph. (1) Bearer. A horizontal member ot & scaffold upon which the platform rests and which may be supported by ledgers. (2) Brace. A tie that holds one scaffold member in a fixed position with respect to another member. . (3) Climbing.ladder. A separate ladder with equally spaced rungs usually at tached to the scaffold structure for climb ing and descending. (4) Coupler. A device for locking to gether the components of a tubular metal scaffold which shall be designed and used to safely support the maximum intended loads. (5) Design working load. The maxi (9) Float or ship scaffold. A scaffold ture used'for supporting workmen or mum intended load, being the total of all hung from overhead supports by means materials or both. loads including the weight of the men, of ropes and consisting of a substantial (28) Single-point adjustable suspen materials, equipment, and platform, platform having diagonal bracing under- sion scaffold. A manually or power- (6) Equivalent. Alternative design or .neath, resting upon and securely fas operated unit designed for light duty features, which will provide an equal tened to two parallel plank bearers at use, supported by a single wire rope from degree or factor of safety. ; .right angles to the span. an overhead support so arranged and (7) Guardrail. A barrier secured toiip- (10) Guardrail. A rail secured to up- operated as to permit the raising or low 'rights and erected along the exposed 'ghts and erected along the exposed ering of the platform to desired working sides and'ends of platforms to prevent .des and ends of platforms. positions. . -:; falls fef persons. : FEDERAL REGISTER} VOL'37, NO. 202--WEDNESDAY. OCTOBER 18. 1972 BFG30378 WQQ9VZ '22108 RULES AND REGULATIONS i?rr;(8) Handrail. A rail connected to a 'ladder stand running parallel to the slope iand/or top step. : (9) Ladder stand. A mobile fixed size self-supporting ladder consisting of a wide flat tread ladder in the form of stairs. The assembly may include hand rails. - (10) Ledger (stringer). A horizontal scaffold member which extends from post to post and which supports the bearer forming a tie between the posts. (11) .Mobile scaffold (tower). A light, medium, or heavy duty scaffold mounted on casters or wheels. (13) Mobile. "Manually propelled." (13) Mobile work platform. Generally a fixed work level one frame high on casters or wheels, with bracing diagon ally from platform to vertical frame. (14) Runner. The lengthwise hori zontal bracing and/or bearing members, (15) Scaffold. Any temporary elevated platform and its necessary vertical, diag onal, and horizontal members used for supporting workmen and materials. (Also known as a scaffold towerJ (16) Toe board. A barrier at platform level erected along the exposed sides and ends of a scaffold platform to prevent falls of materials. (17) Tube and coupler scaffold. An assembly consisting of tubing which serves as posts, bearers, braces, ties, and runners, a base supporting the posts, and uprights, and serves to-join the various members, usually used in fixed locations. (18) Tubular welded frame scaffold. A sectional, panel, or frame metal scaffold substantially built up of pre fabricated welded sections, which con sist of posts and bearers with intermedi ate connecting members and braced with diagonal or cross braces. (19) Tubular welded sectional folding scaffold. A sectional, folding metal scaf fold either of ladder frame or inside stairway design, substantially built of prefabricated welded sections,which con sist of end frames, platform frame, in side inclined stairway frame and braces, or binged connected diagonal and hori zontal braces, capable of being folded into a fiat package when the scaffold is not in use. (2tt) Work level. The elevated plat form, used for supporting workmen and their materials, comprising the necessary vertical, horizontal, and diagonal braces, guardrails, and ladder for access to the work platform. 1910.22 . General requirements. This section applies to all permanent places of employment, except where domestic, mining, or agricultural work only is performed. Measures for the con trol of toxic materials are considered to be outside the scope of this section. (a) Housekeeping. U> All places of employment, - passageways, storerooms, service rooms ahaijt be kept clean and orderly and in a sanitary condition. (2) The floor of every workroom shall be maintained in a clean and, so far as possible, a dry condition.Where wet proc esses are used, drainage shall be main tained, and false floors, platforms, mats. or other dry standing places should be (ii) A removable railing with toe- provided where practicable. board on not more than two sides of the (2) To facilitate cleaning, every floor, opening and fixed standard railings with working place, and passageway shall be toeboards on all other exposed sides. kept free from protruding nails, splinters, The removable railings shall be kept in holes, or loose boards. place when the opening is not in use and (b) Aisles and passageways. (1) Where should preferably be hinged or otherwise mechanical handling equipment is used, mounted so as to be conveniently sufficient safe clearances shall be al replaceable. lowed for aisles, at loading docks, through doorways and wherever turns or pas sage must be made. Aisles and passage ways shall be kept clear and in good re pairs, with no obstruction across or in aisles that could create a hazard. (2) Permanent aisles and passageways shall be appropriately marked. (c) Covers and guardrails. Covers and/ or guardrails shall be provided to protect personnel from the hazards of open pits, tanks, vats, ditches, etc. (d) Floor loading protection. (X) In every building or other structure, or part thereof, used for mercantile, business, in dustrial, or storage purposes, the loads approved by the building official shall be marked on plates of approved design which shall be supplied and securely af fixed by the owner of the building, or his duly authorized agent, in a conspicuous place in each space to which they relate. Such plates shall not be removed or de faced but, if lost, removed, or defaced, shall be replaced by the owner or his agent. (2) It shall be unlawful to place, or cause, or permit to be placed, on any floor or roof of a building or other structure a load greater than that for which such floor or roof is approved by the building official. Where operating conditions necessitate the feeding of material into any hatch way or chute opening, protection shall be provided to prevent a person from falling through the opening. (4) Every skylight floor opening and hole shall be guarded by a standard skylight screen or a fixed standard rail ing on all exposed sides. (5) Every pit and trapdoor floor open ing. infrequently used, shall be guarded by a floor opening cover of standard strength and construction which should be hinged in place. While the cover is not in place, the pit or trap opening shall be constantly attended by someone or shall be protected on all exposed sides by removable standard railings. (6) Every manhole floor opening shall be guarded by a standard manhole cover which need not be hinged in place. While the cover is not in place, the manhole opening shall be constantly attended by someone or shall be protected by remov able standard railings. (7) Every temporary floor opening shall have standard railings, or shall be constantly attended by someone. (8) Every floor hole into which per sons can accidentally walk shall be guarded by either: (i) A standard railing with standard 1910.23 Guarding floor and wall open toeboard on all exposed sides, or ings and holes. (ii) A floor hole cover of standard (a) Protection for floor openings. (1) Every stairway floor opening shall be guarded by a standard railing con structed in accordance with paragraph (e) of this section. The railing shall be strength and construction that should be hinged in place. While the cover is not in place, the floor hole shall be con stantly attended by someone or shall be protected by a removable standard railing. provided cm all exposed sides (except at entrance to stairway). For infrequently used stairways where traffic across the opening prevents the use of fixed stand ard railing (as when located in aisle spaces, etc.). the guard shall consist of a hinged floor opening cover of standard strength and construction and remova ble standard railings on all exposed sides (except at entrance to stairway). (9) Every floor hole into which per sons cannot accidentally walk (on ac count of fixed machinery, equipment, or walls) shall be protected by a cover that leaves no openings more than 1 inch wide. The cover shall be securely held in place to prevent tools or materials from falling through. (10) Where doors or gates open di rectly on a stairway, a platform shall be (2) Every ladderway floor opening or provided, and the swing of the door shall platform shall be guarded by a standard not reduce the effective width to less than railing with standard toeboard on all 20 inches. exposed sides (except at Entrance to opening), with the passage through the railing either provided with a swinging gate or so offset that a person cannot walk directly into the opening. (b) Protection for wall openings and holes. (1) Every wall opening from which there is a drop of more than 4 feet shall be guarded by one of the following: (3) Every hatchway and chute floor (i) Rail, roller, picket fence, half door, opening shall be guarded by one of the or equivalent barrier. following: The guard may be removable but should (i) Hinged floor opening cover of preferably be hinged or otherwise standard strength and construction mounted so as to be conveniently replace equipped with standard railings or per able. Where there is exposure below to manently attached thereto so as to leave falling materials, a removable toe board only one exposed side. When the opening or the equivalent shall also be provided. is not in use, the cover shall be closed When the opening is not in use for han or the exposed side- shall be guarded at dling materials, the guard shall be kept both top and intermediate positions by in position regardless of a door on the removable standard railings.' opening. In addition, a grab handle shall BFG30379 FEDERAL REGISTER, VOL. 37. NO. 202--WEDNESDAY. OCTOBER 18, 1972 RULES AND REGULATIONS 22125 Tabu D-Ift--Hr^orra Nominal Size and Maximum gftiqps m YfrinTyg niriUTftftEa -SCAlTOiJlfl Light duty . .Medium -duty Maximum scaflold load. Outrigger size_________ Siiacing. PlanIrTrig________ Guardrail_________ Guardrail uprights. Toeboards________ 25 pjJ_____ 50p.s.r. 2 x 10 in____ 3 x 10 In. 10 ft-Ota__; it 0 In. .. 2 X 9 In.......... 2 x 9 in. .. 21 4 in.......... 2 I 41n. .. 2x 4 in.......... 2x4 In. .. 4 in. (mini 4 in. (mini mum). mum). (f) ifosoils' adjustable multiple-point suspension scaffolds. (1) The scaffold shall be capable of sustaining a working load of 50 pounds per square foot and shall not be loaded in excess of that figure. (2) The scaffold shall be provided with hoisting machines that meet the require ments of Underwriters' Laboratories or Factory Mutual Engineering Corp. (3) The platform shall be supported by wire ropes in conformity with para graph (a) (22) of this section, suspended from overhead outrigger beams. (4) The scaffold outrigger beams shall consist of structural metal securely fas tened or anchored to the frame or floor system of the building or structure. (5) Each outrigger beam shall be equivalent in strength to at least a stand ard 7-inch, 15.3-pound steel I-beam, be at least 15 feet long, and shall not project more than 6 feet 6 inches beyond the bearing point. (6) Where the overhang exceeds 6 feet 6 inches, outrigger beams shall be com~'osed of stronger beams or multiple ;ams and be installed in accordance *dth approved designs and instructions. (7) If channel iron outrigger beams are used in place of I-beams, they shall be securely fastened together with the flanges turned out. <8) All outrigger beams shall be set and maintained with their webs into vertical position. (9) A stop bolt shall be placed at each end of every outrigger beam. (10) The outrigger beam shall rest on suitable wood-bearing blocks. (11) All parts of the scaffold such as bolts, nuts, fittings, clamps, wire rope, and outrigger beams and their fasten ings, shall be maintained in sound and good working condition and shall be inspected before each installation and periodically thereafter. (12) The free end of the suspension wire ropes shall be equipped with proper size thimbles and be secured by splicing or other equivalent means. The running ends shall be securely attached to the hoisting drum and at least four turns of rope shall at all times remain on the drum. (13) Where a single outrigger beam is used, the steel shackles or clevises with which the wire ropes are attached to the outrigger beams shall toe placed directly over the hoisting drums. (14) The scaffold platform shall be equivalent in strength to at least 2-inch planking. (For pmrimnm planking spans . .. (8) _A11 wire ropes, fiber ropes, slings, see paragraph (a)(9) of this section.) .. hangers, platforms, and other supporting (15) Guardrails .not:less, than 2x4 parts shall be inspected before every in inches or the equivalent and not less than stallation. Periodic Inspections shall be 36 inches or more than 42 Inches high, made while the scaffold is in use. with a mid-rail, when required, of 1x4- (9) ' On suspension scaffolds designed inch lumber or equivalent, and toeboards, for a working toad of 500 pounds no more Shan be installed at all open sides on all than two'men shall be permitted to work scaffolds more than 10 feet above the at one time. On suspension scaffolds ground or floor. Toeboards Shall be a with a working load of 750 pounds, no minimum of 4 inches In height. Wire more than three men shall be permitted mesh shall be installed in accordance to work at one time. Each workman shall with paragraph (a) (17) of this section. be protected by a safety lifebelt attached (16) Overhead protection shall be to a lifeline. The lifeline shall be securely provided on the scaffold, not more than attached to substantial members of the 9 feet above the platform, consisting of structure (not scaffold), or to securely 2-inch planking or material of equivalent rigged lines, which will safely suspend strength laid tight, when men are at the workman in case of a fall. work on the scaffold and an overhead (10) Where acid solutions are used, hazard exists. fiber ropes are not permitted unless acid- (17) Each scaffold shall be installed or proof. relocated in accordance with designs (11) Two-point suspension scaffolds and instructions, of a registered profes shall be securely lashed to the building sional engineer, and supervised by a or structure to prevent them from sway competent, designated person. ing. Window cleaners' anchors shall not (g) Two-point suspension scaffolds be used for this purpose. (stringing scaffolds). (1) Two-point sus- ` (12) The platform of every two-point pension scaffold platforms shall be not suspension scaffold shall be one of the ipgg than 20 inches nor more than 36 following types: inches wide overall. The platform shall be securely fastened to the hangers by U-bolts or by other equivalent means, (2) The hangers of two-point sus pension scaffolds shall be made of wrought iron, mild steel, or other equiva lent material having a cross-sectional area capable of sustaining four times the maximum intended load, and shall be designed with a support for guardrail, intermediate rail, and toeboard. (3) When hoisting machines are used on two-point suspension scaffolds, such mftflhfofrs chan be of a design tested and approved by Underwriters* Laboratories or Factory Mutual Engineering Corp. (4) The roof irons or hooks shall be of wrought iron, mild steel, or other equiva U) The side stringer of ladder-type platforms shall be clear straight-grained spruce or materials of equivalent strength and durability. The rungs shall be of straight-grained nk, ash, or hickory, at least 1% inch in diameter, with seven-eighth inch tenons mortised into the side stringers at least seveneighth inch. The stringers shall be tied together with the tie rods not less than one-quarter inch in diameter, passing through the stringers and riveted up tight against washers on both ends. The flooring strips shall be spaced not more than - five-eighth inch apart except at the side rails- where the space may be 1 inch. Ladder-type platforms shall be constructed- in accordance with table lent material of proper size and design, D-17. securely Installed and anchored. Tiebacks of three-fourth inch manlla rope or the equivalent shall serve as a second ary means of anchorage, installed at right angles to the face of the building whenever possible and secured to a struc turally sound portion of the building. (ii) Plank-type platforms shall be composed of not less than, nominal 2- x 8-inch unspliced planks, properly cleated together on the underside start ing 6 inches from each end: intervals in between shall not exceed 4 feet. The plank-type platform shall not extend (5) Guardrails not less than 2x4 beyond the hangers more than 18 inches. inches or the equivalent and not less than A bar or other effective means shall be 36 inches or more than 42 inches high, securely fastened to the platform at each with a mid-rail, when required, of 1- x 4- end to prevent Its slipping: off the inch lumber or equivalent, and toeboards, hanger. The span between hangers for shall be installed at all open sides on all plank-type platforms shall not exceed scaffolds mare than 10 feet above the 10 feet. ground or floor. Toeboards shall be a minimum of 4 inches in height. Wire mesh shall be installed in accordance with paragraph (a) (17) of this section. (iii) Beam platforms shall have side stringers of lumber not less than 2x6 inches set on edge. The span between hangers shall not exceed 12 feet when (6) Two-point suspension scaffolds beam platforms are used. The floor shall be suspended by wire or fiber ropes. ing shall be supported on 2- and 6-inch Wire and fiber ropes shall conform to crossbeams, laid flat and set into the paragraph (a) (22) of this section. upper edge of the stringers with a snug (7) The blocks for fiber ropes diatl be fit, at intervals of not more than 4 feet, of standard 6-inch size, consisting of at securely nailed in place. The flooring least one double and one single block. shall be of 1- x 6-inch material prop ThA sheaves of all blocks shall fit the size erly nailed. Floorboards shall not be of rope used. . spaced more than one-half Inch, apart. No. 202--Pt. n- FEDERAL REGISTER, VOL. 37, NO. 203--WEDNESDAY, OCTOBER 18, 1972 24358013 22124 RULES AND REGULATIONS <2) A medium-duty tube and coupler degree angle -frees near the -base of -the (11) Drawings and specifications for scaffold sball have all posts, runners, and first outer post upward to the extreme all frame scaffolds over 125 feet in height bracing of nominal 2-inch OJD. steel-tub ~top of -the scaffold. Where "the longi above -the base plates -shall be designed ing.. Posts spaced not more than 6 feet tudinal length of the scaffold permits, by a registered professional engineer and apart by 8 feet along the length of the such bracing shall be duplicated begin copies made available to the employer scaffold shall have bearers xtf -nominal ning--at--every-fifth post.--In -a -similar - mid for inspection purposes. - 2 ^2-inch OJD. steel tubing. Posts spaced manner, longitudinal diagonal bracing (12) All tubular welded frame scaffolds not more than 5 feet apart by 8 feet along shall also be installed from-the last post shall be erected by competent and ex the length of the scaffold shall have extending back and upward toward the perienced personnel. bearers of nominal 2-inch OJD. steel tub first post. Where conditions preclude the (13) Frames and accessories for scaf ing. Other structural metals when used attachment of this bracing to the posts, folds shall be maintained in good repair must be designed to carry an equivalent it may be attached to the runners. and every defect, unsafe condition, or load. (13) The entire scaffold shall be tied noncompliance with this section shall (3) A heavy-duty tube and coupler to and securely braced against .the build be immediately corrected before further scaffold shall have all posts, runners, and ing at intervals not to -exceed 30 feet use of the scaffold. Any broken, bent, ex bracing of nominal 2-inch OJD. steel tub horizontally and 26 feet vertically. cessively rusted, altered, or otherwise ing, with the posts spaced not more than (14) Guardrails mot less than 2x4 .structurally damaged frames or acces 6 feet apart by 6 feet 6 inches along the inches or the equivalent and not less than sories shall not be used. length of the scaffold. Other structural 36 inches or more than 42 inches high, (14) Periodic inspections shall be made metals when used must be designed to with a mid-rail, when required, of of all welded frames and accessories, and carry an equivalent load, lx4-inch lumber or equivalent, and any maintenance, including painting, or (4) Tube and coupler scaffolds shall toeboards, shall be installed at all open minor corrections authorized by the be limited In heights and working levels sides on all scaffolds more than 10 feet manufacturer, shall be made before fur to those permitted in tables E>-13, 14, above the ground or floor. Toeboards ther use. and 15, of section. Drawings and shall be a miniznmn of 4 inches in height. (e) Outrigger scaffolds.-(1) Outrigger specifications of all tube and coupler Wire mesh shall be installed in accord hwtms shah extend not.more than 6 feet scaffolds above the limitations in tables ance with paragraph (a)(11) of this beyond the face of the building. The D-13,14, and 15 of this section shall be section. inboard end of outrigger beams, meas designed bya registered professional en (d) Tubular welded frame scaffolds. ured from the fulcrum point to the ex gineer and copies made available to the (1) Metal tubular frame scaffolds, in treme point of support, shall be not less employer and for inspection purposes. cluding accessories such as braces, brack than one and-one-half times the out (5) All tube and coupler scaffolds shall be constructed and erected to support four times the maximum intended loads as set forthin tables D-13, 14, and 15 of this section, or as .set forth in the speci fications by a registered professional engineer, copies which shall be made available tothe employer and for inspec tion purposes.- -- (6) AO tube and coupler scaffolds shall be erected by competent and ex perienced personnel. (7) Posts shall be accurately spaced, erected on suitable bases, and main tained -plumb.........................................- - ets, trusses, screw legs, ladders, etc., board end in length. The beams shall shall be designed and proved to safely rest on edge, the sides shall be plumb, support four times the maximum and the edges shall be horizontal. The intended load. fulcrum point of the beam shall rest (2) . Spacing of panels or frames shall on a secure bearing at least 6 inches in be consistent with the loads imposed. each horizontal dimension. The beam (3) Scaffolds shall be properly braced shall be secured in place against move by cross bracing or diagonal braces, or ment and shall' be securely braced at both, for securing vertical members to the fulcrum point against tipping. gether laterally, and the cross braces shall be of such length as will automati cally square and align vertical members so that the erected scaffold is always plumb, square, and rigid. All brace con (2) Tha inboard, ends of outrigger beams shall be securely supported either by means of struts bearing against sills in contact with the overhead beams or ceil ing, or by fnftftTTs of tension members nections shall be made secure. secured to the floor 'joists underfoot, or (4) Scaffold legs shall be set on ad by both if necessary. The inboard aids (8) Runners shall be erected along the justable bases or plain bases placed cm of outrigger beams shall be secured length of the scaffold located on both mud silts or other foundations adequate against tipping and the entire supporting the inside and the outside posts at even to support the maximum intended load. structure shall be securely braced in both height.'Runners shall be interlocked to (5) The frames shall be placed one on directions to prevent any horizontal form continuous lengths and coupled to each post. The bottom runners shall be located as close to the base as possible. Runners shall be placed not more than 6 feefc -6 inches on centers. (9) Rearers shall be Installed trans versely between pests and shall be securely coupled to the posts bearing on the runner coupler. When coupled directly to the runners, the coupler must be kept as close to the posts as possible. (10) Bearers shall be at least 4 incites but not more than 12 inches longer than the post spacing or runner spacing. Bearers may be cantilevered for use as "brackets to carry not more than two planks. (I D Cross bracing shall be Installed across the width of the scaffold at.least' every.ttdrdset:cf posts horizontally and every, fourth runner vertically. Such bracing-shallextend fliagonallyfrom the inner and outer, runners upward to the ; top of the other with coupling or stack ing pins to provide proper vertical ahnement of the legs. (6) Where uplift may occur, panels shall be locked together vertically by pins or other equivalent-suitable means. (7) Guardrails not less than 2x4 inches or the equivalent and not less than 36 inches or more than 42 .inches high, with a mid-raTl when required, of .1-x 4inch lumber car equivalent, and toe boards, shall beinstalled at all open sides on all scaffolds more than 10 feet above the ground or floor. Toeboards -shall be a minimum of 4 inches in height. Wire mesh shall be installed tin -accordance with paragraph (a) (17) of this section. (8) All tubular metal scaffolds shall be constructed and erected to support four times the maximum intended loads. (9) To prevent movement, the scaffold shall be securedto the building or struc ture at Intervals not to -exceed 30 feet! horizontally and 26 feet vertically. movement. (3) Unless outrigger scaffolds are de signed by a licensed professional engi neer, they shall be constructed and erected In accordance with "table D-16. Outrigger scaffolds designed by a regis tered professional engineer sballbe con structed and erected in accordance with such design. A copy of the detailed draw ings and-specifications showing the sizes and spacing of members shall be kept on thejob. . (4) Planking shall be laid tight and shall extend to within 3 inches of the building wall shall be nailed or bolted to outriggers. (5) Where there is dangerof material falling from the scaffold, a wire mesh or other enclosure shall he provided be tween the guardrail and the toeboard. (6) Where additional working levels are required to be supported by the out rigger method, the plans and specifica next outer and Inner runners. ; .. tUP Maximum permissible spans of tions of the outrigger and scaffolding . (12) Tjohgitudinal diagonal bracing planking shall be in conformity with structure shall be designed by a regis shall be installed at approximately a 45- paragraph (aH9) of this section. tered professional engineer. FEDERAL REGISTER, VOL. 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 AULES .AND REGULATIONS 22109 be provided on each side of the opening . (3) Regardless of height, open-sided with Its center approximately 4 feet-above flours, walkways, platforms, or runways floor lew! and -of standard strength -and above or -adjacent to -dangerous equip uounting. ment, pickflng or -galvanizing tanks, de (ii) intension platform -onto "Which greasing units, 'and Similar hazards shall 'materials can be hoisted for handling, be guarded with a standard railing and and winch shall have side rails or equiv toe board. alent guards of standard -specifications. fd) Stairway railings ands/uards. (1) (2) Every chute wall opening from Every flight of-staff-shaving four or more which there is a drop of more than 4 feet risers shall be equipped with standard shall be guarded by one or more of the .stair railings or standard handrails as barriers specified in subparagraph (1) cl specified in subdivisions (i) through (v) this paragraph, or as required by the of this subparagraph, the width of the conditions. stair to be measured clear of all obstruc (3) Every window wall opening at a tions excepthandrails; .stairway landing, floor, platform, or (1) On stairways less than .44 inches balcony, from which there Is a drop of wide having both sides enclosed, at least more thsn 4 feet, and where -the -bottom one handrail, preferably on the right tide -of the opening is Jess than 3 feet -above descending. the platform or landing, shall be guarded (ii) On stairways less than 44 inches by standard slats, standard grill work (as wide having one side open, at least one specified in paragraph (e) (11) ol this stair jailing on open side. section), or standard railing. (iii) On .stairways less than 44 inches Where the window opening is below the wide having both sides open, one stair landing, or platform, a standard toe railing on each tide. board shall be provided. (iv) On stairways more than 44 (4) Every temporary wall opening shall have adequate guards but these need not be of standard construction. (5) Where there is a hazard of mate rials falling through a wall hole, and the lower edge of the near side of the hole is less than 4 inches above the floor, and the fax side of the hole more than 5 feet above the next lower level, the hole shall be protected by a standard toeboard, or an enclosing screen either of solid con inches wide hutJess than 88 Inches wide, one handrail on each enclosed side and one stair railing on each open slde. (v) On stairways 88 or more inches wide, one "handrail on each enclosed side, one stair railing on each open side, and oneintermediate stair railing located.ap.proxlmately-midway of the width. (2) Winding stairs shall be equipped with a handrail offset toprevent walking on all portions of Che treadshaving width struction. or as specified In paragraph Jess than 6inches. fe) (11) -of this section. (e) Railing, toe boards, and career '.cY Protection of open-sided floors atforms, and runways. (1) 'Every open sided floor or platform 4 feet or more above adjacent floor or groundlevel shall be guarded by a standard-railing (orthe specifications. (1) .A standard railing shall consist of top raff..intermediate rail, and posts, and shall have a vertical height at 42 inches nominal from upper .surface of top rail tofloor, platform, run equivalent as specified in paragraph te> (3) of *Ms section) on all open sides. ex- way, or ramp level. The top rail shall be smooth-surfaced throughout the length cept where there is entrance to a ramp, stairway, or fixed ladder. The "raffing of the railing. The intermediate rail shall he approximately halfway between `the shall be provided with a toeboard top rail and the floor, platform, runway, wherever, beneath the open sides, . (1) Persons can pass, . or ramp. The ends of the mils shall not overhang the terminal posts except where such overhang does not constitute (ii) There is moving machinery, or a projection hazard. (iii) There is equipment with which (2) A .stair railing -shall be of con falling materials could -create a hazard. struction similar to a -standard railing (2) Every runway shall be guarded by but the vertical height shall .be not-more a standard railing (or the .equivalent as than 34 inches nor -dess -than .30 inches specified in paragraph (e) (3) of this from upper surface of top rati to surface section) on all open tides 4 feet ormore of tread In line withface of riser at for- above floor or ground level. Wherever ward edge of tread. tools, machine parts, or materials ^are -C3) -Minimum xequirements-for stand likely to be used on the runway, a toe board shall also be provided -on each ard .railings under various types of -con struction are specified in the .-following -exposed side. r subdivisions. Dimensions specified are Runways used exclusively for special based mi-the UB. Department of Agricul purposes (such as -tiling, shafting, or ture Wood Handbook, Ho. 72,1955 (Ko.J filling tank cars) may.have the railing on IS4S1 -Southern Yellow .Pine -(Modulus one side omitted where operating condi of .Rupture 7;400 pai.l) for wood; .ANSI tions necessitate such omission,providing G41.5-1970,American National-Standard the falling hazard Is minimized 3zy u1ug Specifications for Structural Steel, lor a.runway of nbt-less than18Jncheswide. structural steel; -and ANSI 31251-1970, Where persons entering upon .runways American National Standard Specifica become thereby exposed jo machinery, tions for Welded -and Steamless Steel electrical equipment, nr other danger.not Pipe*furjfipe.................. a Tailing hazard, (IT .For wood railings, -the .posts .shall ^ ->isherespetilled mayhecsseatiaLIor he of at least 2-inch.-by 4-inch stock x&on., ' Spaced hot .to exceed -Stleefc;. the top and intermediate mils hn be of at least 2-inch by 4-inch stock. If top rail is made of two right-angle pieces of I-Inch by 4-ffich-stock, posts may be spaced on 8-foot centers, with 2-Inch by 4-lnch intermediate tsIL (ii) Forpipe railings, posts and top and intermediaterailings shall be at least 1Vz inches nominal diameter with posts spaced not more than 8 feet on centers. flii) For-stinetmalsteel railings, posts and top and intermediate rails shall be of 2-inch by 2~ineh by %-inch angles or other metalshapes of equivalent bending strength wife posts spaced not more than 8 feet on centers. (iv) The anchoring of posts and framing of members for railings of all types shall be of such construction that the completed structure shall be capable of withstanding a load -of at least 200 pounds applied in any direction at any point on the topTail. (v) iOQier-=iypes, sizes, and arrange ments -of -raffing construction are ac ceptable provided they -meet the follow ing-conditions: <a> A smooth-surfaced top Tail at a height above floor, platform, Tunway, or ramp level of -42 inches nominal; <b) A strength to withstand at least the minimum-requirement of 200 pounds top rail pressure; (c) Protection between top rail and floor, platform, -runway, ramp, or stair treads, -equivalent at least to that af forded by a standard intermediate rail; (d) Elimination of overhang of rail ends unless such overhang does not con stitute a hazard: such as, baluster rail ings, scrollwork-railings, paneled railings. 44) A standard toeboard shall be 4 inches nominal In vertical height from its top edge to the level of the floor, platform, runway, or ramp. It shall be securely fastened in place and with not more than %-inch clearance above floor level. It may be made of any substantial material either solid or with -openings not over 1 inch in greatest dimension. Where material is piled to such height that a standard toeboard does .not pro vide protection, paneling from floor to intermediate rail, or to top rail shall be provided. . S) CD -A .handrail shall consist of a lengthwise member mounted directly on a wall or partition by means of brackets attached-to thelowerside of-thehandrail so as to offer.no.obstruction to a.smooth surface along the top and both tides of the handrail. The handrail -shall be of rounded or other section that will fur nish an adequate handhold for anyone grasping It to avoid failing. The ends of fee handrail .should be -turned in to the supporting wall or otherwise arranged so as hot to constitute -a projection hazard. til) The height of handrails^shall be not more than 34 InchesnorJessthan30 *vr inchesfrom upper surfaceofhandrail to ***- surface oftreadIn line with face of riser CO or to surface xff lamp. ~ .CUD The .rizeaf handrails .shall bei Qft When of hardwood, at Jeast. 2 Jnches.ffi diameter;, when afmetal pipe, at Jeast ^ : Cft No. 202--Pt. n- FEDERAl .REGISTER VOL 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 BFG30380 22110 RULES AND REGULATIONS l^s inches in diameter. The length of more than 8 inches long, or of slatwork reasonably slip-resistant and the nosings brackets shall be such as will give a clear with openings not more than 4 inches shall be of nonslip finish. Welded bar ance between handrail and wall or any wide with length unrestricted. grating treads without nosings are ac projection thereon of at least 3 inches. The spacing of brackets shall not exceed 1910.24 Fixed industrial stairs. ceptable providing the leading edge can be readily identified by personnel de 8 feet. , (a) Application of requirements. This' scending the stairway and provided the (iv) The mounting of handrails shall section contains specifications for the tread is serrated or is of definite nonslip be such that the' completed structure is safe design and construction of fixed design. Rise height and tread width shall capable of withstanding a load of at least general industrial stairs. This classifica be uniform throughout any flight of 200 pounds applied in any direction at tion includes interior and exterior stairs. any point on the rail. around machinery, tanks, and other Tabu D-l <6> All handrails and railings shall be equipment, and stairs leading to or from provided with a clearance of not less than floors, platforms, or pits. This section Angle to horizontal Rise Tread ran (in inches) (in inches) 3 inches between the handrail or railing does not apply to stairs used for fire exit and any other object. i purposes, to construction operations to > 3035'.................................... m 11 (7) Floor opening covers may be of private residences, or to articulated any material that meets the following stairs, such as may be installed on float strength requirements: ing roof tanks or on dock facilities, the 7K (i) Trench or conduit covers and their supports, when located in plant road ways, shall be designed to carry a truck angle of which changes with the rise and fall of the base support. (b) Where fixed stairs are required. :41*44'.................................... 8 SI 9)1 9H 9 rear-axle load of at least 20,000 pounds. (ii) Manhole covers and their sup ports, when located in plant roadways, Fixed stairs shall be provided for access from one structure level to another where operations necessitate regular 4638'.................................... :46*16'.................................... 0 SI 8! 8 shall comply with local standard high way requirements if any; otherwise, they shall be designed to carry a truck rearaxle load of at least 20,000 pounds. (iii) The construction of floor opening covers may be of any material that meets the strength requirements. Covers pro jecting not more than 1 inch above the floor level may be used providing all edges are chamfered to an angle with the horizontal of not over 30 degrees. All hinges, handles, bolts, or other parts shall set flush with the floor or cover surface. (8) Skylight screens shall be of such construction and mounting that they are capable of withstanding a load of at least 200 pounds applied perpendicularly at any one area on the screen. They shall also be of such construction and mount ing that under ordinary loads or impacts, they will not deflect downward suffi ciently to break the glass below them. The construction shall be of grillwork with openings not more than 4 inches long or of slatwork with openings not more than 2 inches wide with length unrestricted. (9) Wall opening barriers (rails, rollers, picket fences, and half doors) shall be of such construction and mount ing that, when in place at the opening, travel between levels, and for access to operating platforms at any equipment which requires attention routinely dur ing operations. Fixed stairs shall also be provided where access to elevations is dally or at each shift for such purposes as gauging, inspection, regular mainte nance, etc., where such work may expose employees to acids, caustics, gases, or other harmful substances, or for which purposes the carrying of tools or equip ment by hand is normally required. (It is not the Intent of this section to pre clude the use of fixed ladders for access to elevated tanks, towers, and similar structures, overhead traveling cranes, etc., where the use of fixed ladders Is common practice.) Spiral stairways shall not be permitted except for special lim ited usage and secondary access situa tions where it is not practical to provide a conventional stairway. Winding stair ways may be installed on tanks and similar round structures where the diam eter of the structure is not less than five (5) feet. (c) Stair strength. Fixed stairways shall be designed and constructed to carry a load of five times the normal live load anticipated but never of less strength than to carry safely a moving concentrated load of 1,000 pounds. stairs including any foundation structure used as one or more treads of the stairs. (g) Length of stairways. Long flights of stairs, unbroken by landings or inter mediate platforms, should be avoided. Consideration should be given to provid ing intermediate platforms where prac tical and where such stairways are in frequent use. Stairway platforms shall be no less than the width of a stairway and a minimum of 30 inches in length measured in the direction of travel. (h) Railings and handrails. Standard railings shall be provided on the open sides of all exposed stairways and stair platforms. Handrails shall be provided on at least one side of closed stairways, preferably on the right side descending. Stair railings and handrails shall be in stalled in accordance with the provisions' of 191023. (i) Vertical clearance. Vertical clear ance above any stair tread to an over head obstruction shall be at least 7 feet measured from the leading edge of the tread. (j) Open risers. Stairs having treads of less than 9-inch width should have open risers. (k) General. Open grating type treads are desirable for outside stairs. the barrier is capable of withstanding a (d) Stair width. Fixed stairways shall 1910.25 Portable wood ladders. load of at least 200 pounds applied in any direction (except upward) at any point on the top rail or corresponding member. have a minimum width of 22 inches. (e) Angle of stairway rise. Fixed stairs shall be installed at angles to the hori zontal of between 30 and 50. Any uni (a) Application of requirements. This section is intended to prescribe rules and establish minimum requirements for the construction, care, and use of the com (10) Wall opening grab bandies shall form combination of rise/tread dimen mon types of portable wood ladders, in be not less than 12 inches In length and sions may be used that will result in a order to insure safety under normal con shall be so mounted as to give 3 inches stairway at an angle to the horizontal ditions of usage. Other types of special clearance from the side framing of the within the permissible range. Table D-l ladders, fruitpicker's ladders, combina wall opening. The size, material, and gives rise/tread dimensions which will tion step and extension ladders, stock- anchoring of the grab handle shall be produce a stairway within the permis room step ladders, aisle-way step ladders, such that the completed structure is sible range, stating the angle to the hor shelf ladders, and library ladders are not capable of withstanding a load of at least izontal produced by each combination. specifically covered by this section. 200 pounds applied in any direction at However, the rise/tread combinations (b) Materials--(1) Requirements ap any point of the handle. are not limited to those given in Table plicable to all wood parts. (1> All wood (11) Wall opening screens shall be of D-l. parts shall be of the species specified in such construction and mounting that (f) Stair treads. Each tread and the Table D-5, seasoned to a moisture con they are capable of withstanding a load top landing of a stairway, where risers tent of not more than 15 percent; of at least 200 pounds applied hori are used, should have a nose which ex smoothly machined and dressed on all zontally at any point on the near side of tends one-half inch to 1 inch beyond the sides; free from sharp edges and splin the screen. They may be of solid con face of the lower riser. Noses should have ters; sound and free by accepted visual struction, of grillwork with openings not an even leading edge. All treads shall be inspection from shake, wane, compres- BFG30381 FEDfRAi REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 RULES AND REGULATIONS 22123 Table D-7--Mmnrmr Nominal Size and Maximum Sfaonq of Mbubebs of Single Pols Scaffolds Light Dutt - "Table D-U--Continued medium butt--continued Maximum height of scaffold Uniformly distributed load__________ ... Poles or uprights_____________ ____ ____ Pole spacing (longitudinal)_____________ Maximum width of scaffold.._____...... Bearers or putlogs to 3 ft. 0 in. width____ Bearers or putlogs to 5 ft. 0 In. width....... Ledgers.................................... -...................... Planting____ ________ ____ ______________ Vertical spacing of horizontal members.__ _ Bracing, horizontal and diagonal.................. Tie-Ins.............................................................. Toeboards.............................. ....................... Guardrail_______________ ................. Not to exceed 25 pounds per square foot; 2by4ln_.............................4 by 4 In. 6 ft. 0 ln_.............................. 10 ft. 0 In. 6ft. Oin............................... 6 ft. Oin. 2 by 4 In...............................2 by 4 In; 2 by 6 in. or 3 by 4 is_____ 2 by 6 in. or 3 by 4 In; (rough). 1 by 4 In........................... 1)4 by 9 In. IH by 6 in. (rough)2 by 9 in. 7 ft. 0 In...............................7ft. Oln. 1 by 4 In...............................1 by 4 in. Iby 4 In............................. i by 4 In. 4 In. high (minimum).___ 4 In. high (minimum). 2 by 4 In............................. 2 by 4 in. All members except planking are used on edge. (17) Wood-pole scaffolds shall not b erected beyond the reach of effective firefighting apparatus. Tawt. D-8~--Mtntmttm Nominal Size and Maximum Spacing or Mbmkers or Single Pols Scaffolds Table D-9--mzmimum Nominal fit?TM aim Maximum Spacing or Mgmmgwa or Single Pole Scaffolds MEDIUM DUTY heavy Dtrrr Uniformly distributed load. Maximum height of scaffold. Poles or uprights..... Pole spacing (longi tudinal). Maximum width of scaffold. Bearers or putlogs____ Spacing of bearers or putlogs. Ledgers______________ Vertical spacing of horizontal members. Bracing, horizontal___ Bracing, diagonal..... Pie-ins_________________ Planking___-_______Toeboards Guardrail ...__...... Not to exceed 50 pounds per square foot. 60 ft. 4 by 4 In. 8 ft. 0 In. 5 ft. 0 In. 2 by 9 in. or 3 by 4 8ft.Oln. . 2 by 9 In. 9 ft. 0 in. I by 8 in. or 1)4 by 4 In. 1 by 4 in. 1 by 4 in. 2 by 9 In. 4 In. high (mini mum). 2 by 4 In. Uniformly distributed Not to exceed 75 load. pounds per square foot. M.irr'-.TTn height of 60 ft. scaffold. Poles or uprights..___ Pole spacing (longl- tudinal). 4 by 4 in. 6 ft. 0 In. Maximum width of 5 ft. 0 In. scaffold. Bearers or putlogs____ 2 by 9 in. or 8 by 5 In. (rough). Spacing of bearers or 6 ft. 0 in. putlogs. Ledgers______________2 by 9 in. Vertical spacing of 6 ft. 6 In. horizontal members. Bracing, horizontal 2by4ln. and diagonal. Tie-ins ......__...... 1 by 4 In. Planking 2 by 9 in. Toeboards........... 4 in. high (mini mum). Guardrail ........... 2 by 4 In. Planking _2 by 9 In. Toeboards------------------- 4 In. high mum) . Guardrail____________ a by a in (mini All members except planking are used on edge. Table T)--12----ItonnjM Nominal Size aits Maximum Spacing or Wnnmn qj Tvnc. pendent Pole Scaffolds exavy duty Uniformly distributed load. Maximum height of scaffold. Poles or uprights______ Pole spacing (longi tudinal) . Pole spacing (trans verse). Ledgers______________ Vertical spacing of horizontal members. Bearers ________________ Bracing, horinoatal and diagonal. Tie-ins ...... Hanking Toeboards_________ ___ Guardrail___ ___________ Not to exceed 75 pounds per square foot. 60 ft. 4 by 4 In. 6 ft. 0 In. 8 ft. Oin. 2 by 9 In 4 ft. 6 in. 2 by 9 in. (rough). 2 by 4 in. 1 by 4 In. 2 by 9 in. 4 in. high mum) . 2 by 4 in. (mini All members except planking are used on edge. Uniformly distributed load.___ Not to exceed 25 p.s.fc Post sparing (longitudinal) 10ft. Oin. Post spacing (transverse)... 6 ft. Oin. Working levels 1 2 3 Additional planted levels 8 4 0 Marimmn height 125ft. 125 ft. 91 ft. Oin-- All members except planking are used on All members except planking are used on Table D-14--Tube asd Couples Scaffolds Medium edge. edge. Durr Table D-lO--Minimum Nominal Bizi and Maximum SFACDto or Mkkbees or Independent Pole Scaffolds Light Dun Uniformly distributed load------- Not to exceed 50 * Pest spacing (longitudinal)........ 8 ft. 0 in. y Post sparing (transverse)______ 6 ft. 0 in. Maximum height of scaffold 20 feet 60 feet Working levels Additional planted levds Maximum height Uniformly distributed load.. Poles or uprights..... .............. Pole spacing (longltudinal).. Pole spacing (transverse).... Bearers to 3 ft. Oln. span............................ Bearers to 10 ft. Oln. span........................... Planking......... Vertical spacing of horizontal members.__ Bracing, horizontal and diagonal_________ Tie-ins................... ....................................... Toeboards............. ........................................ Guardrail................................................... __ Not to exceed 25 pounds per square loot. __ 2 by 4 in...--........... . 4 by 4 In. __6ft. Oln........... .................... 10 ft. Din; __ 6 ft. 0 in...............................10 ft. 0 in. ... 13* by 4 in........................... D*by9inr ... Shy 4 in..... 2 by 4 In. -- 2 by 6 la. or S by 4 In--... 2 by 9 (rough) or 8 by S in. ... IK by 9 In_.............. 2 by 9 In. __ 7ft. OUu............................... 7ft. Oin. __ 1 by 4 In_______ _____ ____ 1 by 4 in. __1 by 41s......... .......................1 by 4 In. 4in. high--........ 4 in. high (minimum); __ 2 by 4 in2 by 4 in. All members except planking are used on edge. Table D-12--Minimum Nominal Size and Maximum Spacing of or Inde pendent Pole Scaffolds MEDIUM DUTY Uniformly distributed ' Not to exceed 50 load. pounds per squats foot. Maximum height of 60 ft. scaffold. Poles or uprights______ 4 by 4 In. Pole spacing (longl- 8 ft. 0 in. tudinal). medium duty*--continued Pole spacing (trans verse). Ledgers ___ Vertical spacing of horizontal members. Spacing of bearers... Bearers ............. Bracing, horizontal___ Bracing, diagonal.... Tie-ins ________________ 8 ft Oln. 2 by 9 In. 6 ft Oln. 8 ft Oln. 2 by 9 in. (rough) or 2 by 10 to. 1 by 6 in. or 1% by 4 in. 1 by 4 In. Iby41n. 1 6 125 ft 2 0 78 ft. Qtn. Table D-15--Tube and Coufleb Scaffolds Heavy Uniformly distributed load........ Not to exceed 75 pxJ. Post spacing (longitudinal)........ 8 ft. 8 In. Post spacing (traverse)............. 6 ft. Oln. Working levels 1 Additional planted levels 6 height 125 ft have all posts, bearers, runners, and brac-J Log of nominal 2-inch OJD. steel tubing^ The posts shall be spaced no more fi feet apart by 10 feet along the length of the scaffold. Other structural metal"> when used must be designed to carry aa* equivalent load. FEDERAL REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 221^ RULES AND REGULATIONS (5) Scaffolds .and other devices men tioned or described in this section shall be maintained in safe condition. Scaf folds shall not be altered or moved .horizontally while they are in use or occupied. (6) Any scaffold damaged or weakened from any cause shall be immediately re paired and shall not be used until re pairs have been completed. (7) Scaffolds shall not be loaded in excess of the working load for which they are intended. (8) All load-carrying timber members of scaffold framing shall be a minimum of 1,500 /. (Stress Grade) construction grade lumber. All dimensions are nom inal sizes as provided in the American Lumber Standards, except that where rough sizes are noted, only rough or un dressed lumber of the size specified will satisfy minimum requirements. (Note: Where nominal sizes of lumber are used in place of rough sizes, the nominal si^e lumber shall be such as to provide equiv alent strength to that specified in tables D-7 through D-12 and D-16.) (9) All planking shall be Scaffold Grade as recognized by grading rules for the species of wood used. The maximum permissible spans for 2- x 9-inch or wider planks are shown in the following table: Material Full thick- Nominal ness undressed thickness lumber lumber ... 25 50 75 Permissible span (ft.)___ ... 10 8 0 25 50 86 The maximum permissible span for 114 x 9-inch-or wider plank of full thick ness is 4 feet with medium loading of 50 p.s.f. (10) Nails or bolts used in the con struction of scaffolds shall be of ade quate size and in sufficient numbers at each connection to develop the designed strength of the scaffold. Nails not be subjected to a straight pull and shall be driven full length. Ul) All planking or platforms shall be overlapped (minimum 12 inches) or secured from movement. (12) An access ladder or equivalent safe access shall be provided. (13) Scaffoldplanks shall extend over their end supports not less than 6 inches nor more than 18 Inches. (14) The poles, legs, or uprights of scaffolds shall be plumb, and securely and rigidly braced to prevent swaying and displacement. (15) Materials being hoisted onto a scaffold shall have a tag line. (16) Overhead protection shall be pro vided for men on a scaffold exposed to . .overhead hazards. (17) Scaffolds shall be provided with - a screen between the toeboard and the .guardrail, extending along the entire - opening, consisting of No. 18 gauge U.S. ..'Standard Wire one-half-inch .mesh or - the equivalent, where persons are re quired to work nr pass under the scaffolds. (18) Employeesshall network on scaf folds-dining storms or high winds. (19) Employees shall not work on scaf folds which are covered with ice or snow, unless all ice or snow is removed and planking sanded to prevent slipping. (20) Tools, materials, and debris shall not be allowed to accumulate in quanti ties to cause a hazard. (21) Only treated or protected fiber rope shall be used for or near any work involving the use of corrosive substances or chemicals. (22) Wire or fiber rope used for scaf fold suspension shall be capable of sup porting at least six times the intended load. (23) When acid solutions are used for cleaning buildings over 50 feet in height, wire rope supported scaffolds shall be used. (24) Theuse of shore scaffolds or leanto scaffolds is prohibited. (25) Lumber sizes, when used in this section, refer to nominal sizes .except where otherwise stated. (26) Scaffolds shall be secured to per manent structures, through use of an chor bolts, reveal bolts, or other equiva lent means. Window cleaners' anchor bolts shall not be used. (27) Special precautions shall be taken to protect scaffold members. In cluding any wire or fiber ropes, when using a heat-producing process. (b) General requirements for wood pole scaffolds. CL) Scaffold poles shall bear on a foundation of sufficient size and strength to spread the load from the poles over a sufficient area to prevent settlement. All poles shall be set plumb. (2) Where wood poles are spliced, the ends shall be squared and the upper sec tion shall rest squarely on -the lower sec tion. Wood splice plates shall be provided on at least two adjacent sides and shall not be less than 4 feet 0 inches in length, overlapping the abutted ends equally, and have the same width and not less than the cross-sectional area of the pole. Splice plates of other materials of equivalent strength may be used. (3) Independent pole scaffolds shall be set as near to the wall of the building as practicable. (4) All pole scaffolds.shall be securely guyed nr tied to the building or struc ture. Where the height or length exceeds 25 feet, the scaffold .dian be secured -at Intervals not greater than 25 feet verti cally and horizontally. (5) Putlogs or bearers shall be set with their greater dimensions vertical, long enough to project over the ledgers of the timer and outer rows of poles at least 3 Inches for proper support. (6) Every wooden putlog on single pole scaffolds shall be reinforced with a x 2-lnch steel strip or equivalent se cured to its lower edge throughout its entire length. Cl) ledgers shall be long enough , to extend over two pole spaces. Ledgers shall not be spliced between the poles. Ledgers shall be reinforced by bearing blocks securely nailed to the side of the pole to form a support for the ledger. (8) Diagonal bracing shall be provided to prevent the poles from moving in a direction parallel with the wall of the building, or from buckling. (9) Cross bracing shall be provided between the inner &nd outer sets of poles In independent pole scaffolds. The free ends of pole scaffolds shall be cross braced. (10) Pull diagonal face bracing RhnJi be erected across the entire face of pole scaffolds in both directions. The braces shall be spliced at the poles. (11) Platform planks shall be laid with their edges close together so the plat form will be tight with no spaces through which tools or fragments of material can fall. (12) Where planking is lapped, each plank shall lap its end supports at least 12 inches. Where the ends of planks abut each other to from a flush floor, the butt joint shall .be at the centerline of a pole. The abutted aids shall rest on separate bearers. Intermediate beams shall be provided where necessary to prevent dislodgment of planks due to deflection, and the ends shall be nailed or cleated to prevent their dislodgment. (13) When a scaffold turns a corner, the platform planks shall be laid to pre vent tipping. The planks that meet the corner putlog at an angle shall be laid first, extending over the diagonally placed putlog far enough to have a good safe bearing, but not far enough to in volve any danger from tipping. The planking running in the opposite direc tion at right angles shall be laid so as to extend over and rest on the first layer of planking. (14) When moving platforms to the next level, the old platform shall be left undisturbed until the new putlogs or bearers have been set in place, ready to receive the platform planks. (15) Guardrails not less than 2x4 inches or the equivalent and not less than 36 inches or more than 42 inches high, with a mid-rail, when required, of 1 x 4-inch lumber or equivalent, and toeboards, shallbe installed at all open sides on ah scaffolds more than 10 feet above the ground or floor. Toeboards shall be a minimum -of 4 inches in height. Wire mesh shall be installed in accordance: with paragraph (a) (17) of this section.. (16) All wood pole scaffolds 60 feet or less in height shall he constructed and erected in accordance with tables D-7 through D-12 of this section. If they are over 60 .feet In height -they shall be designed by* registered.professional en gineer andconstructedand erected in ac cordance with such design. A copy of the typical drawings and specifications shall be made available to the employer and for inspection purposes. FEDERAL REGISTER, YOt. 37, N0. 2C2--WEDNE3DAT, OCTOBER IS, 1972 RULES AND REGULATIONS 22U1 sion failures, decay, or other ir'regulari- (11) The general slope ^of grain and - (ii) 'Forfiihe:stile rails of angle exten Jes except as hereinafter provided. Low- that in areas of local deviations of grain sion-mxd .'sectional tedders, the proposed nsity wood shall not he -used. shall not be steeper thani in15 In rungs eection shall flevefap an actual stress per - (ii) 'Black streaks ha -western hemlock shall not be considered an irregularity, except that chambers .associated with black streaks, when present in the'part, shall be limited as specified lor pitch and bark pockets. (2) Permissible irregularities m side rails and back rails, (i) The general slope of grain in side rails of minimum dimen sion shall not be steeper than 1 in 12, except that for ladders under 10 feet in length and having flat steps for treads, the general slope of grain shall not be steeper than l in 10. The slope of grain in areas of local grain deviation shall not be steeper than 1 in 12 or 1 in 10 as specified above when occurring on the edges or in the outer one-fourth of the width of the wide face. Local areas of grain deviation within the center half of the width of the wide face may con tain grain slope as steep as 1 in 8. Local deviations of grain associated with other wise permissible irregularities are permitted. (ii) Knots shall not appear in narrow faces of side rails. Knots, if tight and sound and less than one-half inch .In diameter, are permitted on the wide face provided they are at least one-half inch back from either edge and not more frequent than l to any 3 -feet of ladder length. and cleats. ^Por all ladders cross .grain not steeper than! in l2areq>ermitted in lieu 'of 1 in 45, provided tire -size is -in creased to afford at least 15 percent greater calculated strength lor ladders built to minimum dimensions. Local de viations of grain associated with other wise permissible irregularities are permitted. (iii) Knots over one-eighth inch in di ameter shall not appear on rungs. Knots shall not appear in the narrow faces of fiat steps and cleats. Knots appearing in the wide faces of flat steps and cleats shallnot exceedsdiameter of one-fourth inch. (4) Classification of species of wood. Table D-5 gives a list of native woods, divided into four groups on the basis of mechanical properties considered from the standpoint of use lor ladder construction. (i) ah TTimimTiTn dimensions ancLspec- ificatians set forth hereinafter lor side rails and flat steps are based on the species of woodhstedin Group 3 in Table D-5 except where otherwise provided. The species <of ah other groups may be substituted for those of Group 3 when used insizes that provide at least equiva lent strength. (See .Table D-5 lor sug gested methods of si adjustment.) (ii) All minimum dimensions and specifications set forth hereinafter for square finch mot .greater Than 2,150 pounds for Group 1 woods, -2JQ00 pounds for Group 2 woods, 1,-600 .pounds for Group 3 woods, -or -1,375 -pounds for Group 4 woods -when computed by the following formula applying to rectangu lar sections, with a m&yimnm tolerance of 5 percent over -these -stresses: 3XD (P+TV/OS) 1.5XD (25+Wyi6) 2B [IP--cf>) B (D*--0.67) P=25 pounds, which Is the normal componetrt-un each rail of a load of .200 -pounds at the center of the ladder, equally distributed between .the rails, when the foot of the ladder is moved out of -the perpendicular by one-quarter of its length. . S=Stress in extreme fiber tn pounds per square Inch. W ==Weigbt of ladder m pounds.' L=Maximumworking length of ladder in inches. - B^'Net -thickness of each side rail in inches. D=Dejrtliof side rail in .inches. -d=Diameter of hole board for .rung (d* shall be taken as not less than 0.67). (iii) Adjustment of sizes for wood parte of .steptedders and other ladder types covered by this section may be made as follows: (a) The dimensions specified in later sections ;for pacts having -rectangular cross sections -generally represent only Oil) Pitch and bark pockets are per- rungs and-cleats are based on the species one of a number of possible combina `ted .provided they are not more than of wood listed in Group 1 in 'Table D-5. tions of thicknea and width which could -eighth inch in width, or more than Cleats may be made of species of any satisfy the requirements for strength z inches in length, or more than one- other group jnovided that the cross- and stiffness. Depending -upon the mate half inch in depth,.and then only if they are not more frequent than 1 to any ,3 Factostoe Increase in rial sizes available, manufacturing prac tices,-and like Tactors. partsproduced by feet of.ladder length. <iv) Checks are permitted-on side rails provided they are not more than 6 inches Species group Each WWthonty dimension (thickness .unchanged) a -particular manufacturer may or may not agree -exactly with the sizes given later. The following provisions provide in length or more than one-half inch in mpjms for determining equality of load depth. carrying capacity of parts of different (v) Occurrences of compression wood 4... ________________ _____ in relatively small amounts -and posi LJ7 sizes nr of determining sizes needed to t28 provide equality. tively identified by -competent and con scientious visual inspection of side -rails are permitted provided no single streak shall' exceed one-half inch in width nor shall the aggregate of streaks exceed one-fourth of the face of the side rail. sectional dimensions specified for Group 1 species are increased by the factors shown in this subdivision (based on the percentages of Table D-5) for the species group of which the-cleats are to be made. (5) Metal parts. All metal parts shall - '(b) Any changes in dimensions .-shall result ln a change in the width-thickness ratio for side rails of back legs not greater than 25 percent from the ratio for a corresponding -ladder as now covered in this-section. Borderline forms of compression wood be made of aluminum, steel, wrought (e) Where both -dimensions are dif not positively identified by competent iron, malleable iron, or other material, ferent from those -specified, the load and conscientious visual inspection are permitted. Ladder parts containing bow or crook which would interfere with the operation of the ladder shall not be used. adequate in strength for the purpose intended. (c) Construction . requirements--(1) Basis of requirements, (i) Dimensions carrying -capacity tn bending of a part will be equal to -or greater than that of a part of specified dimensions if the ratio Pa/Pi is not.less than 1, where (3) Permissible irregularities in flat specified hereinafter for wood ladders are steps, rungs, and cleats, (i) The general the minimum dressed -cress-sectional P Srf)*> slope of grain in flat steps of minimum dimensions for the types of ^ladders Pi BiPi* dimension shall not be steeper than 1 In herein designated, based -on -the aperies and 12,-except that -for -ladders under 40 -feet in length the slope of grain shall not be steeper than 1 in 10. The slope of grain in areas of local deviation shall not be steeper than lin 12 or lin 10-as-speci fied above. For all ladders, -cross grain not, steeper than 1 in 10 are permitted in lieu of 1 in 12, provided the size is in' --ed to afford at least 15 percent -of woods specified-in paragraph -fbH-4) -of this section, at a moisture content of 15 percent The dimensions for side rails are based on a mortise or gain as speci fied tor the various types ol ladders Tor step or rung attachments. Where the -strength -of the aide -rails -or back legs-is reduced by a .greater mortise or gain than -shown, nr where it is desired to use 3t=dDtmension of the part at right angles to the -direction at load (width -of a step, thickness of a i8iderallnr back-leg). p --tuttipuki.rrt thp pact parallel to the direction of load (thickness -of a -step, -width of ;a Tide -rail or -- baCkTeg), ' -- - XJiiaSimeBdainsApecffled. ' AtOi^DlincDdQefflfjHnitiwbgeooddWBd. *er calculated strength than.for lad ders built to minimum dimensions. Local deviations of grain associated with other wise permissible irregularities are a cross sect!cm for .any wood.part either dimension of which- -is less--than that specified, the required dimensionsmaybe found as indicated in subdivision (ii) of ' `The tlimensfcns To be `used In the computations 'are -net dimensions. For example, in the case of a stepladder tide rail,The -fllmensitat B is'to be taken -as Permitted. this subparagraph. the^gross thickness.of the rafl minuothe FEDERAL REGISTER, VOL. 37, NO. 202--WEDNESDAY,' OCTOBER' 7 8, 3972 243S8006 BFG30382 22112 RULES AND REGULATIONS depth of the gain for the steps. Where there is a-rung hole at the center of depth of a: rail, a somewhat more ac curate comparison may be made by the use of the formula : p, sip, Pi BlDs (4>-d3) where the symbols have the same mean ings as before and d is the diameter of the hole: for the rung tenon. In most instances the difference in results cal culated by this and by the earlier formula will be slight. (2) Portable stepladders. Stepladders longer than 20 feet shall not be supplied. Stepladders as hereinafter specified shall be of three types: Type I--Industrial stepladder, S to 20 feet for heavy duty, such as utilities, contractors, and Industrial use. Type n--Commercial stepladder, 3 to 12 feet for medium duty, such as painters, offices, and light industrial use. Type IH--Household stepladder, 3 to 6 feet for light duty, such as light household use. (i) General requirements, (c) Slope is the inclination of side rails or back legs with respect to the vertical and is ex pressed as a deviation from the vertical per unit length of the member. Stepladders shall be so constructed, that when in the open position, the slope of the front section shall not be less than 3% inches and the slope of the back sec tion not less than 2 inches, for each 12-inch length of side rail. (b> A uniform step spacing shall be employed which shall be not more than 12 inches. Steps shall be parallel and level when the ladder is in position for use. (e) The minimum width between side rails at the top, inside to inside, shall be not less than 11% inches. Prom top to bottom, the side rails shall spread at least 1 inch for each foot of length of stepladder. (d) When minimum thickness of side rails is used, steps shall be closely fitted into the grooves in the side rails oneeighth inch in depth with a tolerance of one thirty-second inch, and shall be firmly secured as hereinafter described; or they shall be closely fitted into metal brackets of an equivalent strength, which in turn shall be firmly secured to the side rails. The depth of groove herein provided may be increased in proportion to the thickness of side rails as provided in subdivisions (ii) to), (ill) (a), and (iv) (a) of this subparagraph. (e) All stepladders shall have a top with wood or metal brackets or fittings tightly secured to the top, side rails, and back legs, to allow free swinging of toe back section without excessive play or wear at toe joints. (/) A metal spreader or locking device of sufficient size and strength to securely hold the front and back sections in open positions shall be a component of each stepladder. The spreader shall have all sharp points covered or removed to pro tect the user. For Type in ladder, the . pail shelf and spreader may be combined in-one unit (the so-called shelf-lock ladder),. - (g) When measured along the front edge of the side rails, all stepladders shall measure within 3 inches of the specified length. - (ft) Where bucket shelves are pro vided, they shall be constructed to sup port a load of 25 pounds and shall be so fastened that they can be folded up when the ladder is closed. (t) All metal parts and fittings shall be securely attached by means of rivets, bolts, screws, or equivalent fasteners. (ii) Type I industrial stepladder. (a) (I) The minimum dimensions of the parts of the Type I stepladder shall be as shown in Table I>-2 when made of Group 2 or Group 3 woods. (2) The minimum thickness of side rails provides for the cutting of a groove of one-eighth into in depth with the tolerance indicated in subdivisions (i) (d) of this subparagraph, and shall be increased when grooves of greater depth are used. <b) Steps shall be secured with at least two 6-d nails at each end, or the equiva lent thereof. Each step shall be rein forced by a steel rod not less than 0.260 inch in diameter with standard commer cial tolerances, which shall pass through metal washers of sufficient thickness and diameter on each end to prevent press ing--into toe side rails, and a truss block which shall be fitted between toe rod and the center of each step, or by a metal angle brace on each end firmly secured to the steps and side rails, or by con struction of equivalent strength and safety. Where toe rod reinforcement construction is used, toe bottom step shall be provided further with a metal angle brace on each end which shall be securely attached to the bottom step and side rails. In addition, all steps 3% inches wide and 27 inches or more in overall length and all steps 4% inches wide and 32 inches or more in overall length shall be provided with a metal angle brace at each end securely attached to the step and side rail. (c) The back section shall be braced by one of the following methods: (1) The back legs shall be braced with 1%-inch diameter rungs of Group l woods (see Table D-5), or material of equivalent strength, having %-into di ameter tenons or oval wood rungs, or rectangular wood rungs of equivalent strength,-spaced not more than 12 inches apart. The back legs shall be bored with holes either extending through the legs or to within three-sixteenths inch of the outside face of the legs, toe size of the hole to be such as to insure a tight fit for the rung. The shoulder of the rung shall be forced firmly against toe leg, and the tenon secured in place with a nail, or the equivalent thereof, to prevent turning of the rungs. The back legs shall be braced by a metal angle brace on each side, se curely fastened to the rung and the back legs, one rung to be braced for each 4 feet of length or fraction thereof, on ladders 4 feet or more in length, with braces re quired only on the bottom rung for lad ders that are 4 feet or shorter. Where rungs are more than 28 inches in length between the back legs they shall be pro vided with center bearing consisting of a wood bar not less than % by 2 inches in cross-section securely nailed to each rung passing through it and long enough to include each rung longer than 28 inches. (2) The back leg shall be braced with horizontal wood bars of Group 1, 2, or 3 woods in Table D-5 and not less than % by 2% inches in cross-section, spaced not more than 12 inches apart. The ends of the bars shall fit into metal sockets of not less than 20-gauge (Manufactur ers Standard) steel, or other material of equivalent strength, or into mortises of not less than one-eighth inch (tolerance of one-thirty-second inch) in depth in the back legs. A steel rod not less than 0.260 inch in diameter with standard commercial tolerance shall pass through the back legs, the bar, and at each end through metal washers of sufficient diam eter and thickness to prevent passing into the back legs. The back legs shall also be braced by a metal angle brace on each side, securely fastened to the bar and to the legs, one bar to be so braced for at least each 4 feet of length or fraction thereof, with braces required only on bottom bar for ladders that are 4 feet or shorter. Metal sockets when used shall be attached to the back legs by rivets or by means of a rod running through the socket or equivalent thereof. Table D-2 DIMENSIONS FOB TYPE I STEP LADDER Length, 12 feet and less Length, U and 16 feet Length. 18 and 20 left Side rails....___ Tops................... Thickness .. <l"`> K :: h X Depth (inches) 3k! in Thickness (inch) X X H Depth (inches) -3 Thickness (inch) 1M# 1K m Depth (inches) SX 2X Table D-3 DIMENSIONS FOB TYPE 11 STEF LADDER Length, 3 to 8 (eet Length, 10 feet Length, 12 feet Tops__ i____ --- -------------' Thickness (tneh) X Depth (.inches) 2X Thickness (inch) X 5k Depth (inches) 2X 3H 5 Thickness (inch) X X X % " Depth (inches) 3 m * FEDERAL REGISTER, VOL.~ 37,-NO. 202--WEDNESDAY, OCTOBER 18,-7 972 BFG30383 ;RULES AND; REGULATIONS .nor more, than 24 inches clearance be tween rails. For side-step or offset fixed ladder sections, at landings, the side rails and rungs shall be carried to the next regular rung beyond or above the 3% feet minimum (flg.D-10).^.. . ; :- (4) Grab bars. Grab bars shall be spaced by a continuation of the rung spacing when they are located in the horizontal position. Vertical grab bars shall have the same spacing as toe ladder side rails. Grab-bar diameters shall be 22121 SHOKT LABDfre AT ELEVATED LOCATIONS Fionas D-9.--Cages--Special applications. o (vi) Ladder wells shall have a dear width of at least 15 inches measured O3 each way from toe centerline of toe ladder. Smooth-walled wells shall be a minimum of 27 inches from the center- line of rungs to the well wall on the climbing side of the ladder. Where other obstructions on the climbing side of the ladder exist, there shall be a minimum of 30 inches from the centerline of the rungs. (2) Landing platforms. When ladders are used to ascend to heights exceeding 20 feet (except on chimneys), landing 'latforms shall be provided for each 30 .eet of height or fraction thereof, except that, where no cage, well, or ladder safety device is provided, landing plat Fig. D-10 forms shall be provided for each 20 feet of height or fraction thereof. Each ladder section shall be offset from ad jacent sections. Where installation con ditions (even for a short, unbroken length) require that adjacent sections be offset, landing platforms shall be pro vided at each offset. (i) Where a man has to step a dis tance greater than 12 inches from the centerline of the rung of a ladder to the nearest edge of structure or equipment, a landing platform shall be provided. The minimum step-across distance shall be 2% inches. (ii) All landing platforms shall be equipped with standard railings and toeboards, so arranged as to give safe access to the ladder. Platforms shall be not less than 24 inches in width and 30 inches in length. (iii) One rung of any section of ladder shall be located at toe level of the land ing laterally served by the ladder. Where access to the landing is through toe lad der, the same rung spacing as used on the ladder shall be used from the landing platform to toe first rung below the landing. Offset Fixed Ladder Sections the equivalent of the round-rung diameters. (5) Ladder safety devices. Ladder safety devices may be used on tower, water tank, and chimney ladders over 20 feet in unbroken length in lieu of cage protection. No landing platform is re quired in these cases. All ladder safety devices such as those that incorporate lifebelts, friction brakes, and sliding at tachments shall meet the design require ments of the ladders which they serve. (e) Pitch--(1) Preferred pitch. The preferred pitch of fixed ladders shall be considered to come in the range of 75 degrees and 90 degrees with the horizon tal (fig. D-ll). (2) Substandard pitch. Fixed ladders shall be considered as substandard if they are installed within the substandard pitch range of 60 and 75 degrees with the horizontal. Substandard fixed lad ders are permitted only where it is found necessary to meet conditions of installa tion. This substandard pitch range shall be considered as a critical range to be avoided, if possible. (3) Ladder extensions. The side rails (3) Scope of coverage tn this section. of through or side-step ladder extensions This section covers only fixed ladders shall extend 3% feet above parapets and within the pitch range of 60 degrees and landings. For through ladder extensions, 90 degrees with the horizontal. he rungs shall be omitted from the (4) Pitch greater than 90 degrees. extension and shall have not less than 18 Ladders having a pitch in excess of 90 Pilch of Fixed Ladders degrees with the horizontal, are prohibited. (f) Maintenance. AH ladders shall be maintained in a safe condition. All lad ders shall be inspected regularly, with the intervals between inspections being determined by use and exposure. 1910.28 Safely requirements for scaf folding. (a) General requirements for all scaf folds. (1) Scaffolds shall be furnished and erected in accordance with this standard for persons engaged in work that. cannot be done safely from the ground or from solid construction, ex cept that ladders used for such work shall conform to 191025 and 1910.26. (2) The footing or anchorage for scaf folds shall be sound, rigid, and capable of carrying the maximum intended load without settling or displacement. Un stable objects such as barrels, boxes, loose brick, or concrete blocks shall not be used to support scaffolds or planks. (3) Guardrails and toeboards shall be installed on all open sides and ends of platforms more than io feet above the ground or floor except: (i) Scaffolding wholly within the in terior of a building and covering the en tire floor area of any room therein and not having any side exposed to a hoist way, elevator shaft, stairwell, or other floor openings, and (ii) Needle-beam scaffolds and floats in use by structural iron workers. Guardrails should ail be 2 x 4 inches or the equivalent, installed no less than 36 inches or not more than 42 inches high, with a midrail, when required, of^ 1- x 4-inch lumber or equivalent. Sup-Cw ports should be at intervals not to exceed^ tea feet. Toeboards shall be a minimum^} of'4 inches in height;- (4) - Scaffolds and their components shall be capable of supporting without failure at least four times the maximum^ intended load. FEDERAL REGISTER; VOL. 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972' 22120 RULES AND' REGULATIONS jeet in back erf. the'grab bars shall be not less than 4 inches. Grab bars shall not protrude on the climbing side beyond the rungs of the ladder which they serve. (6) Step-across distance. The stepacross distance from the nearest edge of ladder to the nearest edge of equipment or structure shall be not more than 12 inches, or less than 2^ inches (fig. D-4). (ii) Cages or wells (except as provided in subparagraph (5) of this paragraph) conforming to the dimensions shown in'figures D-7, D-8, and D-9 sha.il be provided on ladders of more than 20 feet to.a maximum unbroken length of 30 feet. (iii) Cages'shall extend a ipinitnnm of 42 inches above the top of landing, unless other acceptable protection is provided. than 4 inches, or portion of cage opposite ladder shall be carried to the base. <v) Cages shall not extend less than 27 nor more than 28 inches from the centerline of the rungs of the ladder. Cage shall not be less than 27 inches in width. The inside shall be clear of projections. Vertical bare shall be located &t a maximum^- spacing of 40 degrees around the circumference of the cage; (iv) Cages shall extend down the ladder to a point not less than 7 feet nor more than 8 feet above the base of the ladder, with bottom flared not less Gearanee Diagram for Fixed Ladder in Well Figure D-7 Ladder Far from Wall (7) Hatch cover. Counterweighted hatch covers shall open a minimum of 60 degrees from the horizontal. The dis tance from the centerline of rungs or cleats to the edge of the hatch opening on the climbing side shall be not less than 24 inches for offset wells or SO inches for straight wells. There shall be no protruding potential hazards within 24 inches of the centerline of rungs or cleats; any such hazards within 30 inches of the Centerline of the rungs or cleats shall be -fitted with deflector plates placed at an angle of 60 degrees from the horizontal as indicated in figure D-5. ItAOUCH LMPCR SIK-S1EP lMOS PLATFORM THROUGH LADDER FROM LADDER Ikfleclor Plslet for Head Hsurdf ........................ Fit, .0-5. .. The relationship of a fixed ladder to an acceptable counterweighted hatch cover is illustrated'in figure D-6. (d) Special requirements--(1) Cages or wells, (i) Cages or wells (except on chimney ladders) shall be built, as shown on the applicable drawings, covered in detail in figures D-7, D-8, and D-9, or of equivalent construction. BASKET GUARD HOOP MR LM0CR " BASKET GUARD HOOP ANGLE MON 1*001* Fig. D-8 Cages for Ladders More Than 20 Feet High FEDERAL REGISTER, VOL. 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 RULES AND REGULATIONS 22113 (d) The back legs shall be reinforced (3) With horizontal bracing of Group ing Standard) steel or other material of , by a rivet through the depth of the leg 1, 2, 3, or 4 woods (see Table D-5) not equivalent strength or into mortises not above the hinge point, by metal plates less than % by 2 inches in cross-section, less than, one-eighth inch in depth in or collars at the hinge point, or by other the ends of which shall fit into metal back legs. The bars shall be reinforced by means suitable for preventing splitting sockets of not less than 20-gauge (Man steel rods not less than 0.160 inch in of the back leg from the hinge pin to the ufacturing Standard), steel, or other diameter . with : standard commercial top.- material of equivalent strength or into tolerances which shall pass through the (iii) Type II commercial stepladder. mortises not less than one-eighth inch back leg, the bar, and at each Old (O) (f) The minimum dimensions of the in depth in back legs. The bars shall be through metal - washers of sufficient parts of the Type n stepladder shall be reinforced by steel rods not less than diameter and thickness to prevent press as given in Table D-3 when made of 0.160 Inch in diameter with standard ing into each leg. The spacing of such Group 2 or Group 3 woods. commercial tolerances which shall pass bars shall not exceed 3 'feet, and there (2) The minimum thickness of side through the back legs, the bar, and, at shall be one brace on 3- and 4-foot rails provides for the cutting of a groove each end, through metal washers of suffi ladders, two braces on 5- and 6-foot of one-eighth inch in depth with the tol cient diameter and thickness to prevent ladders. The bottom bar shall- be not erance indicated in subdivision (i) (d) of pressing into the back legs. The spacing more than 18 inches from the bottom of this subparagraph, and shall be increased when grooves of greater depth are used. <b) Steps shall be secured with at least two 6-d nails at each end. or the equiva lent thereof. Each step shall be rein forced by by a steel rod not less than 0.160 inch in diameter with standard commercial tolerances which shall pass through metal washers of sufficient .thickness and diameter on each end to prevent pressing into the side rails, and a truss block shall be fitted between the truss rod and center of each step; or by a metal angle brace on each end firmly secured to the steps and side rails; or by construction of equivalent strength and safety. Where the rod reinforcement con struction is used, the bottom step shall be provided further with a metal angle brace on each end which shall be securely attached to the bottom step and side ails. In addition all steps 27 inches or .lore in overall length shall be provided with a metal angle brace at each end securely attached to the step and side rails. (e) The back legs shall be braced by one of the three following methods: _ (1) (i) With %-inch diameter wood dowels of Group 1 woods (see Table D-5) or material of equivalent strength having hot less than %-inch tenons firmly se cured In the back legs and spaced not more than 12 inches apart. The back legs shall be bored with holes either extending through the legs or to within three-six teenths inch of the outside face of the legs, the size of the hole to be such as to insure a tight fit for the dowel. The shoulder of the dowel shall be forced firmly against the leg and the tenon se cured in place with a nail, or the equiva lent thereof,,to prevent turning of the dowel. (it) A bar connecting two or more of the dowels shall be provided on all lad ders of 6 feet or more. The cross-sec tional dimensions of the bar shall be the same as the cross-sectional dimensions of the back legs, and the dowels shall pass through holes at the centerline of the bar. The bar shall be attached at the center of the length of the lower two dowels on a 6-foot ladder and shall ex tend upward one dowel for each 2 feet of 'added length. .; t-(2.) With wood dowels as set forth in is subdivision (ill) (c) (7), plus an inrted V bracing of %- by 1^-inch ma terial through which the dowels extend, the length of the V to extend two-thirds of such braces shall not exceed 3 feet, mid the ladder. there shall be one brace on 3- and 4-foot ladders, two braces on 5- and 6-foot lad ders, three braces on 7- and 8-foot ladders, and four braces on 10- and 12foot ladders. The bottom bar shall not be more than 18 inches from the bottom of the ladder, and, where only one bar is used, it shall be braced by a metal angle brace on each end securely at tached to the bar and the back leg. (iv) Type III household stepladder. (a) The minimum dimensions of the parts of the Type IH stepladder shall be as follows when made of Group 2 or Group 3 woods: (3) Portable rung ladders. Portable rung ladders as herein specified shn.ii be of four types, as follows: single ladder; two-section extension ladder; sectional ladder; trestle and extension trestle ladder. (I) General requirements, (o) The base or lower portion of a ladder may have either parallel sides ox flared sides in accordance with commercial practice. (b) Rungs shall be parallel, level, and uniformly spaced. The spacing shall be not more than 12 inches, except as here inafter specified. (c) All holes for wood rungs H*il Length, 3 to 6 feet Thickness Depth (Inch) ` (Inches) either extend through the side rails or be bored so as to give at least a thirteensisteenths-inch length of bearing to the rung tenon. In through-bored construc rsfte Back legs................... Steps ... -- ... 2J4 tion, the rungs shall extend at least flush with the outside rail surface. All holes H 3 shall be located on the center fine of the H S wide face of the side rails and shall be The minimum thicknesses of side rails provide for the cutting of a groove oneeighth inch in depth with the tolerance indicated in subdivision (i) (d) of this subparagraph, and shall be increased when grooves of greater depth are used. (b) Steps shall be secured with at least one 6-d nail at each end, or the equivalent thereof. Each step shall be reinforced by a steel rod not less than 0.160 inch in diameter with standard commercial tolerance which shall pass through metal washers of sufficient thickness and diameter to prevent press ing into the side rails, or by a metal brace at each end firmly secured to steps and side rails or by construction of equivalent strength and safety. Where the rod reinforcement construction is used, the bottom step shall be provided of such size as to insure a tight fit for the rung. The shoulder of the rung shall be forced firmly against the side nils and the tenon secured in place with a nail or the equivalent thereof, for the sole purpose of preventing the turning of the rung and maintaining the rung posi tion in the side rail. (<f) Round rungs shall be of Group 1 woods (see Table D-5), shall be not less than 1% inches in diameter for lengths up to 36 inches between side rails ar>41% inches in diameter for lengths over 36 up to and including 72 inches, and shall have not less than seven-eighths-inchdiameter tenons, or rungs of equivalent strength and bearing shall be provided. When rungs are 28 inches or more in length between side rails, they aha]] in addition, be provided with center bearing. further with a metal angle brace on each (e) Oval rungs or rungs of any other end which shall be securely attached to cross section may be used provided they the bottom step and side rail. are secured by a nail at each end or the (c) Back legs shall be braced by one of the two following methods or by con struction of equivalent strength and equivalent thereof, and have at least the same strength and bearing as round rungs of the same length. safety: </) All metal parts and fittings shall be (1) By diagonal slates of groups 1, 2, 3, or 4 wood (see Table D-5) not less securely attached by means of rivets, v - bolts, screws, or equivalent fasteners. (V than A by ly4 inches securely fastened (?) The construction and assembly of to the back legs by nails, screws, or the the movable parts shall be such that they f>3 equivalent thereof. shall operate freely and securely without r (2) With horizontal bracing of Groups binding or unnecessary play. v. ij'' (ft) When measured along the slde^f 1,2, 3, or 4 wood (see Table D-5) not less than % by 1% inches in cross section, the - rails, no rung ladder or.sectioa thereof C3 ends of which shall fit into metal sockets shall be more than 4 inrfian shorter than^CS 1 of the way up the back,. of not less than 20-gauge (Manufactur the specified length.' ............... FEDERAL REGISTER, VOL. 37, NO. 202--WEDNESDAY, OCTOBER 18,1972 BFG30384 22114 RULES AND REGULATIONS (i) Nonslip bases shall be securely bolted, riveted, or attached by equivalent construction to the side rails. (j) Hooks shall be securely bolted or riveted to the side rails or equivalent construction and shall be ol such dimen sions as to withstand the loads imposed upon them. (ii) Single ladder, (a) Single ladders longer than 30 feet shall not be supplied. <b> The minimum dimensions of the side rails of the single ladder shall be as follows when made of group 2 or group 3 woods: Length of ladder (feet) Thickness Depth (inches) (Inches) Up to and Including 16.................. Over 16 up to and Including 22... Over 22 up to and Including 80... (c) Smaller side rails will be accept able in all ladders of this type when rein forced by a steel wire, rod, or strap run ning the length of the side rails and ade quately secured thereto. .Where such reinforcement is used, the reinforced rails shall be equivalent in strength to the side rails specified in this subdivision (ii) <b), (d) The width between the side rails at the base, inside to inside, shall be at least 11'/2 inches for all ladders up to and including 10 feet. Such minimum widths shall be increased at least one- fourth inch for each additional 2 feet of length. (iii) Two-section ladder, (a) Two-sec tion extension ladders longer than 60 feet shall not be supplied. All ladders of this type shall consist of two sections, one to fit within the side rails of the other, and arranged in such a manner that the upper section can be raised and lowered. (b) The minimum dimensions of the side rails of the two-section extension ladder shall be not less than specified in Table D-4 of this section. (c) The minimum dimensions of side rails set forth in Table D-4 are based on the maximum working length, which is the she of ladder less the minimum over lap, which shall be as follows: Overlap Size of ladder (feet): {feet) "Up to and Including 36 3 Over 36 up to and including 48_____ 4 Over 48 up to and including 60_______ 5 (d) Smaller side rails will be accept able in all ladders of this type when reinforced by a steel wire, rod, or strap running the length of the side rails and adequately secured thereto. Where such reinforcement is used, the reinforced rails shall be equivalent in strength to the side rails specified in Table D-4. (e) The minimum distance between side rails of the bottom section, inside to inside, shall be 14% inches on ladders up to and including 28 feet; 16 inches on all ladders over 28 feet up to and including 40 feet; 18 inches on all lad ders over 40feet. (/) All locks and guide irons' shall be of metal and shall be of such construc tion and strength as to develop the full strength of the side rails. All locks shall be positive in their action. The guide irons shall be securely attached and so placed as to prevent the upper section from tipping or falling out while rais ing, lowering, or in use. (g) (1) Ladders of this type may be equipped with a rope and pulley, which shall be securely attached to the ladder in such manner as not to weaken either the rungs or the side rails. The pulley shall be not less than 1% inches in diameter. (2) The rope used with the pulley shall be not less than five-sixteenths inch in diameter having a Tmtiimum breaking strength of 560 pounds, and shall be suffi cient length for the purpose intended. (iv) Sectional Ladder, (a) Assembled combinations of sectional ladders longer than lengths specified in this subdivision shall not be used. (b) The minimum dimensions of side rails shall be as follows for Group 2 or Group 3 woods: Assembled length of ladder (feet) Thickness Depth (inches) (inches) Up to and Including 2i__.___ Over 21 up to and including 31.. IK m (c) Ladders of this type shall have either straight sides slightly converging toward the top of each section, or shall have flaring sides at the bottom of the first (or bottom) section, with the top section having converging side rails to a width that shall be not less than 4 inches. Except for the top section, the minimum width between side rails shall be 11 inches. (f) Adjacent sections shall be jointed by means of a groove in file bottom end of each rail of the upper of the two sec tions setting firmly over extensions out side the side rails, of the topmost rung of the next lower section and, at the Table D-4--Dimensions of Side Rails foe TwoSection Ladder. RaU Site of ladder, overall length--------------------- (feet) Thickness Depth (inches) (Inches) Tot group 2 woods IMe 1H* IMe IMe UIH4t IMe For groups woods same time, a groove in the top end of each rail of file lower of the two sections setting firmly over the bottom rung, in side the side rails, of the section next above. (2) The distance between the two rungs (top-most rung of one section, bot tom rang of the section next above) mentioned in this subdivision (iv) (c) it) shall not be less than 1 foot. (3) The fit between rail grooves and rungs mentioned in this subdivision (iv) (e) (f) shall be such as to provide a good fit without binding or unnecessary play. (4) The grooved ends of the sections shall be reinforced with a metal plate of not less than 18-gauge (Manufacturing Standard) material properly secured thereto, and a rivet adjacent to the groove, extending through the depth of the rail; or the equivalent thereof. (v) Trestle and extension trestle lad der. (q) Trestle ladders, or extension sec tions or base sections of extension trestle ladders longer than 20 feet shall not be supplied. (b) The minimum dimensions of the side rails of the trestle ladder, or the base sections of the extension trestle lad der, shall be as follows for Group 2 or Group 3 woods: Size of ladder (feet) Thickness Depth (inches) (inches) Up to and Including 16................. Over 16 up to and including 20.. 1M* 3 The minimum dimensions of the side rails of the extension section of the ex tension trestle ladder, which shall have parallel sides, shall be as follows for Group 2 or Group 3 woods: Size ofladder (feet) Thickness Depth (inches) (inches) Over 12 up to and including 16.. Over 16 up to aDd including 20.. 2K 2M Vi (c) Trestle ladders and base sections of extension trestle ladders shall be so spread that when in an open position the spread of the trestle at the bottom, inside to inside, shall be at least 5% inches per foot of the length of the ladder. (d) The width between the side rails at the base of the trestle ladder and base sections of the extension trestle ladder shall be at least 21 inches for all ladders and sections up to and including 6 feet. Longer lengths shall be increased at least 1 inch for each additional foot of length. The width between the side rails of the extension sections of the trestle ladder shall be not less than 12 inches. (c) The tops of the side rails' of the trestle ladder and of the base section of the extension trestle ladder shall be bev eled, or equivalent construction, and shall be provided further with a metal hinge to prevent spreading. (/) A metal spreader or locking device to hold the front and back sections in an open position, to hold the extension section securely in the elevated position, shall be a component of all extension trestle ladders and all trestle ladders over 12 feet in length. (g) Rungs shall be parallel and level. On the trestle ladder, or on the base sec tions of the extension trestle ladder. BFG30385 FEDERAL REGISTER, VOL. 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 RULES AND REGULATIONS 22119 (iv) The top of the ladder must be placed with the vwo rails supported, un'ess equipped wifii a single support at tachment. Such an attachment should be substantial angf large enough to sup port the ladder under load. (v) When ascending or descending, the climber must face the ladder. (vi) Ladders must not be tied or fas tened together to providtlonger sections. They must be equipped with the hard ware fittings necessary if the manufac turer endorses expended uses. (vii) Ladders should not be used as a brace, skid, guy or gin pole, gangway, or for other uses than that for which they were intended, unless specifically recom mended for use by the manufacturer. (viii) Users are cautioned to take proper safety measures when metal lad ders are used in areas containing electric circuits to prevent short circuits or elec trical shock. 1910.27 Fixed ladders. (a) Design requirements--(1) Design considerations. All ladders, appurte nances, and fastenings shall be designed to meet the following load requirements: (1) The minimum design live load shall be a single concentrated load of 200 pounds. (ii) The number and position of addi tional concentrated live-load units of 200 pounds each as determined from antici pated usage of the ladder shall be con sidered in the design. (iii) The live loads imposed by per sons occupying the ladder shall be con sidered to be concentrated at such points as will cause the maximum stress in the structural member being considered. (iv) The weight of the ladder and at tached appurtenances together with the live load shall be considered in the design of rails and fastenings. (2) Design stresses. Design stresses for wood components of ladders shall not exceed those specified in 1910.25. All wood parts of fixed ladders shall meet the requirements of 1910.25(b). For fixed ladders consisting of wood, side rails and wood rungs or cleats, used at a pitch in the range 75 degrees to 90 degrees, and intended for use by no more than one person per section, single lad ders as described in 1910.25(c)(3) (ii) are acceptable. (b) Specific features--(1) Rungs and cleats, (i) All rungs shall have a mini mum diameter of three-fourths inch for metal ladders, except as covered in subparagraph (7) (i> of this paragraph, and a minimum diameter of 1% inches for wood ladders. (ii) The distance between rungs, cleats, and steps shall not exceed 12 inches and shall be uniform throughout the length of the ladder. (iii) The minimum clear length of rungs or cleats shall be 16 inches. (iv) Rungs, cleats, and steps shall be free of splinters, sharp edges, burrs, or projections which may be a hazard. (V) The rungs of an individual-rung ladder shall be so designed that the foot cannot slide off the end. A suggested design Is shown in figure D-l, Ficuss D--I.--suggested design for rungs on individual-rung ladders. (2) Side rails. Side rails which might be used as a climbing aid shall be of such cross sections as to afford adequate grip ping surface without sharp edges, splinters, or burrs. (3) Fastenings. Fastenings shall be an integral part of fixed ladder design. (4) Splices. All splices made by what ever means shall meet design require ments as noted in paragraph (a) of this section. All splices and connections shall have smooth transition with original members and with no sharp or extensive projections. (5) Electrolytic action. Adequate means shall be employed to protect dis similar metals from electrolytic action when such metals are joined. (6) Welding. All welding shall be in ac cordance with the "Code for Welding in BuildingConstruction" (AWSD1.0-1966). (7) Protection from deterioration, (i) Metal ladders and appurtenances shall be painted or otherwise treated to resist corrosion and rusting when location de mands. Ladders formed by individual metal rungs imbedded in concrete, which serve as access to pits and to other areas under floors, are frequently located in an atmosphere that causes corrosion and rusting. To increase rung life in such atmosphere, individual metal rungs shall have a minimum diameter of 1 inch or shall be painted or otherwise treated to resist corrosion and rusting: (ii) Wood ladders, when used under conditions where decay may occur, shall be treated with a nonirritating preserva tive, and the details shall be such as to prevent or minimize the accumulation of water on wood parts. (iii) When different types of materials are used in the construction of a ladder, the materials used shall be so treated as to have no deleterious effect one upon the other. (c) Clearance--(1) Climbing side. On fixed ladders, the perpendicular distance from the centerline of the rungs to the nearest permanent object on the climb ing side of fire ladder shall be 36 inches for a pitch of 76 degrees, and 30 inches for a pitch of RO degrees (fig. D-2 of this section), with minimum clearances for intermediate pitches varying between these two limits in proportion to the slope, except as provided in subpara graphs (3) and (5) of this paragraph. (2) Ladders without cages or wells. A clear width of at least 15 inches shall be provided each way from the centerline of the ladder in the rrtimhfng space, ex cept when cages or wells are necessary. (3) Ladders with cages. or.:baskets. Ladders equipped with cage or basket are excepted from the provisions of subparagraphs (1) and (2) of this para graph, but shall conform to the provi sions of paragraph (d) (1) .v) of this sec tion, Fixed ladders in smooth-walled wells are excepted from fire provisions of subparagraph (1) of this paragraph, but shall conform to the provisions of paragraph (d) (1) (vi) of this section. (4) Clearance in back of ladder. The distance from the centerline of rungs, cleats, or steps to the nearest permanent object in back of the ladder shall be not less than 7 inches, except that when un avoidable obstructions are encountered, minimum clearances as shown in figure D-3 shall be provided. (5) Clearance in back of grab bar. The distance from the centerline of the grab bar to the nearest permanent ob- V EHC- RAIL LADDER WITH BAR STEEL RAILS AND ROUND STEEL RUNGS Tig. D-a Minimum Ladder Clearances Clearance, for Unavoidable ObatniClum at Rear of Fixed FEDERAL REGISTER,. VOL. 37; NO. 202---WEDNESDAY, OCTOBER 18, 1972 orosscfcz 22118 RULES AND REGULATIONS Width spread shall not be less than 1 (v) The rung shall be so secured to The following rules and regulations are inch per foot of rise. the side rail that a torque load of 360 essential to the life of the equipment and (iii) Slope of the front rail when unit inch-pounds applied to the rung at a side the safety of the user. is in open position shall not be less than rail shall cause no visible relative motion (2) Care of ladders, (i) Ladders, like 31/2 indies per foot of rise, and the back between the rung and the side rail. any tool, must be handled with care and section shall have a minimum slope of (vi) With the ladder extended to its not subject to unnecessary dropping, 1 inch per foot of rise. maximum working length, and resting jarring, or misuse. They are designed for (iv) The platform shall be at least 20 horizontally on level supports located 6 a specific purpose or use; therefore, any inches from the top of the ladder, and inches from each end of the ladder, a variation from this use constitutes a mis shall have an area of not less than 200 weight of 50 pounds shall be suspended handling of the equipment. square inches nor more than 400 square from one of the side rails midway be (ii) Ladders should be stored on racks inches. tween supports. designed to protect the ladder when not (v) The back legs and side rails of a The deflection of the loaded rail, and the in use. The racks should have sufficient platform ladder shall extend at least 20 difference in deflection between the supporting points to prevent any possi inches above the platform and shall be loaded and unloaded rails shall not ex bility of excessive sagging. connected with the top member to form ceed the values in Table D-6. (iii) Ladders transported on vehicles a three-sided top guard rail, or equiva (vii) Deflections in Table D-6 are to must be properly supported. Supporting lent construction shall be provided. be determined by measuring, at the mid points should be of a softer material, (vi) Spreaders shall be provided where point between supports, the distance such as hardwood or rubber-covered iron the hinging apparatus is not designed to from the outside edges of both rails to pipe, to minimize the chafing and effects lock the unit open. the floor or other reference surface both of road shock. Tying the ladder to each (b) resting. (1) General. The follow before and after the test load of 50 support point will greatly reduce damage ing tests are intended to insure uniform pounds is applied to one rail of the lad due to road shock. testing methods for metal ladders. der. The test is to be repeated loading the (iv) Ladders must be maintained in (2) Straight and extension ladders. other rail of the ladder. The angle (a) good usable condition at all times. Hard Ci) T-adder inclined strength is measured between the loaded and unloaded rails ware fittings and accessories should be by placing the ladder unit in a flat, hori- and the horizontal is to be calculated checked frequently and kept in good zontal position, supported 6 inches from from the trigonometric equation: working condition. the ends of the side rails. When testing extensions, the unit is opened to the Difference in deflection Sine a= ` Ladder width (v) Ropes or cables should be in spected frequently and replaced if de required overlap. A load of 200 pounds is applied equally to the side rails at the center of the unit by means of a beam. The ladder must withstand this test with no permanent deformation or other visible weakening of the structure. This test Is based on a 200-pound man using the ladder, set at 75% to the ground. With the man on the center rung, the component ot his 200-pound weight at right angles to the ladder will be 50 pounds. Applying the load factor of 4, the test weight becomes 200 pounds. (ii) Test unit need only be of sufficient length for test purposes and is to consist of the base and fly sections of an exten sion ladder with all the hardware or fit tings attached. The ladder unit is placed In a vertical position and a downward load of 775 pounds equally distributed on the ends of the side rails of the upper portion of the test unit. The unit shall withstand tills test with no permanent deformation or other visible weakening of the structure. (iii) A test unit of at least three rungs Is to be used from the maximum width portion of the ladder. A load of 800 pounds shall be applied to a 3%-inch wide block resting on the center of the widest rung. A rung of 14 inches or less in length Khali withstand this test with no permanent deformation or other visi ble weakening of the structure. A rung of more than 14 inches In length may have a permanent deflection of not more than one-eighth toch provided the rung cross section is not deformed and there is no other visible weakening of the structure. (iv) With at least a three-rung test (3) Step, trestle, extension trestle, and platform ladders, (i) (a) Load test of the entire ladder is made with the ladder in an open position, and an 800-pound load applied to the center of the top. Resist ance to side rail bending is tested by placing an 800-pound load on the center of the middle step: The strength of the step section is tested by applying an 800pound load to a 3%-inch-wide block resting on the center of the longest or bottom step. The pail shelf shall be so constructed as to support a distributed load of 50 pounds. <b) In each test case, the unit must withstand the load without failure or permanent deformation. (U) Set ladder in open position on a level floor. Place a 200-pound distrib uted load on the top step. The ladder is then subjected to a horizontal pulling load, applied at the top step, of 12-pound force to the side; 58-pound force to the front; 33-pound force to the back. In each test, all side rails must remain on the floor. Table D-S-Table or Deflections Maximum difference In Length of Maximum deflec deflection between ladder In feet tion of loaded loaded and unloaded nil in inches rails in degrees from horizontal 20 3.0 24 3.8 4.6 32 3.5 36 6.4 40 7.2 44 8.0 48 8.8 3.6 4.7 5.4 5.7 6.1 6.6 6.5 6.5 fective. (vi) Complete ladder inspection should be periodical. If a ladder is involved in any of the following, immediate inspec tion is necessary: (a) If ladders tip over, inspect ladder for side rails dents or bends, or exces sively dented rungs; check all rung-toside-rail connections; check hardware. connections: check rivets for shear. (b) If ladders are exposed to excessive heat as in the case of fire, the ladder should be inspected visually for damage and tested for deflection and strength characteristics. In doubtful cases, refer to manufacturer. (c) If ladders are to be subjected to certain acids or alkali solutions, a pro tective coating such as asphalt and var nish should be applied to the equipment. (d) If ladders are exposed to oil and grease, equipment should be cleaned of oil, grease, or slippery materials. This can easily be done with a solvent or steam cleaning. (vii) Ladders having defects are to be marked and taken out of service until repaired by either maintenance depart ment or the manufacturer. (3) Use of ladders, (i) Portable non self-supporting ladders should be erected at a pitch of 75% degrees for maximum balance and strength. A Simple rule for setting up a ladder at the proper angle is to place the base a distance from the vertical wall equal to one-fourth the working length of the ladder. (ii) Portable ladders are designed as a one-man working ladder based on a 200pound load. unit set in a vertical position, a load of (c) Care and maintenance of lad (iii) TThe ladder base section must be a", 800 pounds shall be applied to a 3-inch ders--(I) General. To get maximum placed with a secure footing. Safety shoes i -* wide block resting on the center rung serviceability, safety, and to eliminate of good substantial design should be in as near to the side rail as possible. On w removing the load, the unit must show no indication ,of failure in the fasteners unnecessary damage of equipment, good safe practices in the use and care of lad der equipment must be employed by the stalled on all ladders. Where ladders with no safety shoes or spikes are used on hard, slick surfaces, a foot-ladder board attaching the rungs to the side rail. users. should be employed. FEDERAL REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER 18, 1972 RULES AND REGULATIONS 22115 rungs shall be spaced not less than 8 ncbes or more than 18 inches apart; on le extension section of the extension trestle ladder, rungs shall be spaced not less than 6 inches or more than 12 inches ' (feet) Side rails Thick- Depth ws - (inches) (inches) Diameter Rung, Tenon (inches) (inches) shelving or other permanent structure at not over 3 feet. (vii) Wheel carriages, (a) Wheel car- riages shall be so designed as to provide for all loads to which they will be sub apart. (4) Special-purpose ladders. All spe cial-purpose ladders shall comply with the appropriate requirements of sub- paragraphs (1), (2), and (3) of this Up to and including 22.. Over 22 np to and including 40.................... m ' 3 m 1H m jected. Two-point suspension should be I used. (b) The wheel carriage for the top 1 end of the ladder shall be securely fas tened to the top of the ladder with metal paragraph, except as hereinafter modi fied in this subparagraph. (i) Platform stepladder. A platform stepladder is a modification of a portable stepladder with a working platform pro vided near the top. (a) Platform stepladders shall be made in accordance with the require ments of type I stepladders or in accord ance with the requirements for type II stepladders. ' <b) The slope of the back section shall be such that a vertical from the back edge of the platform will strike the floor at a distance measured toward the front section of not less than 3 inches from the base of the back section. (c) The minimum width between side (c) The width between the side rails at the bottom rung, inside to inside, shall be not less than 12 inches for all ladders up to and including 10 feet. Such mini mum widths shall be increased by at least one-fourth inch for each additional 2 feet of length. id) Rungs shall be parallel and level and shall be spaced not less than 8 inches or more than 12 inches apart. (5) Trolley and side-rolling ladders-- (i) Length. Trolley ladders and side rolling ladders longer than 20 feet should not be supplied. (ii) Dimensions. The dimensions of the side rails shall not be less than the fol lowing for Group 2 or Group 3 woods: brackets bolted either to the side rails or to the top step. When bolted to the top step, this step shall be secured to the side rails with metal braces in addi tion to those otherwise provided. The wheel carriage shall be so designed that a loose or broken wheel will not allow the ladder to drop or become detached from the track. (c) The wheel carriage for the bot tom end of the ladder shall be securely fastened to the bottom of the ladder. (d) The wheels at the upper end of the ladder shall have minimum wheel base of 8 inches. (e) When wheels are used at the bot tom of the ladder, there shall be at least one wheel supporting each side rail rails at the platform shall be not less . (/) Running gear for bottoms of both than 15 inches. (d) The back legs and side rails shall LeDgth of side rails (feet) Thickness Depth (loch) (inches) trolley and side-rolling ladders shall be so designed and constructed as to pro extend at least 24 inches above the plat form and shall be connected with a top Over 10 op to and including 20... member to form a three-sided rail, or *44* **4 vide for any load to which they will be 3 subjected. (d) Care and use of ladders--(1) equivalent construction shall be provided. <e) Platforms shall be so constructed as to be .capable of supporting a load of **00 pounds placed at any point on the atform. (/) A separate spreader may be omitted from platform ladders in which the height to the platform is 6 feet or The minimum thicknesses of side rails provide for the cutting of a groove not over one-eighth inch in depth and shall be Increased when grooves of greater depth are used. Flat steps .shall have the following minimum iHmanstona for Group 2 or Group 3 woods: Care. To insure safety and serviceability the following precautions on the care of ladders shall be observed: (i) Ladders shall be maintained in good condition at all times, the joint be tween the steps and side rails shall be tight, all hardware and fittings securely attached, and the movable parts shall less. If the spreader is omitted, the plat operate freely without binding or undue form shall be so designed as to function as a spreader or locking device to hold Length of step (Inches) Thiekneffl Width play. (inch) (inches) (ii) Metal bearings of locks, wheels, the front and back sections securely in an open position, with the connection be tween side rails and back legs being Ud to and including 16__......... Over 16 np to and including 20... *44* pulleys, etc., shall be frequently lubri 3 cated. m (iii) Frayed or badly worn rope shall through the metal parts of the platform. Over 24 op to and including 28... *44* be replaced. The wood parts of a combined wood and (iv) Safety feet and other auxiliary metal platform functioning as a spreader (iii) Width. The width between the equipment shall be kept in good condi shall not be depended upon to contribute side^ rails, inside to inside, shall be at tion to insure proper performance. to the spreading or locking action. least 12 inches. (v) Ladders should be stored in such (ii) Painter's stepladder. (c) Painter's (iv) Step attachment. Flat steps shall a manner as to provide ease of access stepladders longer than 12 feet shall not be inset in the side rails one-eighth inch or inspection, and to prevent danger of 1 be snpplied. and secured with at least two 6-d nails accident when withdrawing a ladder for (b) Painter's stepladders shall be made at each end or the equivalent thereof. use. - in accordance with the requirements of They shall be reinforced with angle (vi) Wood ladders, when not in use, type n stepladders except for the fol braces or a %6-inch steel rod. should be stored at a location where they lowing: (v) Locking device. Locking devices will not be exposed to the elements, but (1) The top may be omitted. should be provided on all trolley ladders. where there is good ventilation. They (2) A rope spreader may be substi (vi) Tracks, (a) Tracks shall be wood, shall not be stored near radiators, stoves, tuted for the metal spreader required In or metal (excluding cast iron), or a com steam pipes, or other places subjected to subparagraph (2) (1) (f) of this para bination of these materials. excessive heat or dampness. graph. The rope shall not be less than (b) Tracks for the top end of ladders (vii) Ladders stored in a horizontal No. 6 sash cord or its equivalent. shall be fastened securely and shall be so position should be supported at a suf <Ui) Mason's ladder. A mason's ladder constructed that the wheels will not ficient number of points to avoid sag is a special type of single ladder intended jump the track. Tracks shall be so de ging and permanent set. for use in heavy construction work. signed as to provide for all probable loads (viii) Ladders carried on vehicles () Mason's ladders longer than 40 to which they will be subjected.. should be adequately supported to avoid feet shall not be supplied. (c) The supports shall be securely fas - sagging and securely fastened in posi- () The minimum riimpnginng of the tened by lag screws; machine, hook, or . ticm to mfaimim chafing and the effects side rails when made of Group. 2 or toggle bolts, or their equivalent. of road shocks. *.> ; . Group 3 woods and rungs (Group 1 id) Track for side-rolling ladders (lx) Ladders should be kept coated xxis) of the mason's ladder shall be as shall be supported by metal or wood with a suitable protective material. The flows: brackets securely screwed or bolted to painting of ladders Is satisfactory pro- FEDERAL REGISTER, VOl. 37, NO. 202--WEDNESDAY, OCTOBER T 8, 1972 BFG30386 24358008 '22116 RULES AND REGULATIONS S -gifting the ladders are carefully inspected - . prior, to painting by competent and Size at ladder (feet): Overlap (feet) experienced inspectors acting for, and responsible- to, the purchaser, and pro viding the ladders are not for resale. Up to and including 36_______________ Over 36 up to and Including 48_______ Over 48 up to and including 60----------- 3 4 5 (xl) Ladders shall be inspected fre (xiv) Portable rung ladders with re quently and those which have developed inforced rails (see paragraphs (c)(3) defects shall be withdrawn from service (ii) (c) and (iii) (d) this section) shall be for repair or destruction and tagged or used only with the metal reinforcement marked as "Dangerous, Do Not Use." . on the under side. Ladders of this type (xi) Rungs should be kept free of should be used with great care near grease and oil. electrical conductors, since the reinforc (2) Use. The following safety precau ing itself is a good conductor; tions shall be observed in connection (xv) No ladder should be used to gain with the use of ladders: access to a roof unless the top- of the (i) Portable rung and cleat ladders ladder shall extend at least 3 feet above shall, where possible, be used at such a the point of support, at eave, gutter, or pitch that the horizontal distance from roof line; the top support to the foot of the ladder (xvi) Adjustment of extension lad is one-quarter of the working length of ders should only be made by the user the ladder (the length along the ladder when, standing at the base of the ladder, between the foot and the top support). so that the user may observe when the The ladder shall be so placed as to pre locks are properly engaged; Adjustment vent slipping, or it shall be lashed, or of extension ladders from the top of the held in position. Ladders shall not be ladder (or any level over the locking used in a horizontal position as plat device) is a dangerous practice and forms, runways, or scaffolds; should not be attempted. Adjustment (ii> Ladders for which dimensions are should not be made while the user is specified should not be used by more standing on the ladder. than one man at a time nor with ladder (xvii) Middle and top sections of sec jacks and scaffold planks where use by tional or window cleaner's ladders should more than one man. is anticipated. In not be used for bottom section unless the such cases, specially designed ladders user equips them with safety shoes. with larger dimensions of the parts (xviii) Extension ladders should al should be procured;. ways be erected so that the upper section (hi) Portable ladders shall be so Is resting cm the bottom section. placed that the side rails have a secure (xix> The user should equip all port footing. The top rest for portable rung able rung ladders with nonslip bases and. cleat ladders shall .be reasonably when there is a hazard of slipping. Non rigid and shall have ample strength to slip bases are not intended as a sub support the appliedload; stitute for care in safely placing, lash (iv> Ladders shall not be placed in ing, or holding a ladder that is being front of doors opening toward the ladder ' used upon oily, metal, concrete, or slip unless the door is blocked upon, locked, pery surfaces. . or guarded. (xx) The bracing on the back legs of (v) Ladders shall not be placed on step ladders is designed solely for in boxes, barrels, or other unstable bases to creasing stability and not for climbing. obtain additional bright; (vi) To support the top of the ladder at a window opening, a board should be attached across the back erf the ladder, extending across the window and provid. ing firm support against the building walls or window frames; (vii) When Moriifting or descending, the user should face the ladder; (viii) Ladders with broken or missing ' steps, rungs, or cleats, broken side rails, or other faulty equipment shall not be (xxi) When service conditions war rant, hooks may be attached at or near the top of portable ladders to give added security. Table D-5--Classification or Various Spe cies or Wood Acceptable for Use in Lad ders The species are listed alphabetical within each group. The position of any species within a group therefore bears no relation to Its strength or acceptability. Where ladders are desired, for use under , used; improvised repairs shall not be conditions favorable to decay. It is recom made. mended that the heartwood of decay- (ix) Short ladders shall not be spliced resistant species be used, or that the wood together to provide long sections; (x) Ladders made by fastening cleats across a single rail shall not be used; (xi) Ladders shall not be used as be given a treatment with a wood preserva tive. The species having the most durable heartwood are marked with an asterisk (*), and these should be preferred where resist ance to decay is required. guys, braces, or skids, or for other than their intended purposes ; CROUP i (xii) Tops of- the ordinary types of stepladders shall not be used as steps; (xiii) On two-section extension lad ders t-hfr mfrrimwm overlap for the two The allowable fiber stress in bending for the species listed herein when used, for side rails shall not exceed 2,166 pounds per square Inch. These species may be substituted for Group 3 woods on the following basis: The sections in use shall be as follows; dimensions may be not more than 10 per cent smaller for each cross-section dimen sion, or the thickness may remain un changed, In which case the width may not be more than 15 percent smaller if used edgewise (as in a rail) or 25 percent smaller if used flatwise (as in a tread). White ash____:____ Fraxlnus amerlcana. pennsylv&nica, quad- rangulata Beech Fagus grandifolla Birch Betula lenta, alle- ghanlensls, nigra (2) Rock elm_______... Ulmus thomasii Hickory____________ Carya ovata, laclniosa, tomentosa, glabra Locust*____________ Robinta pseudoacacia, Gledltsla triacanthos Hard maple________ Acer nigrum, sac- charum Red maple_________ Acer rubrum (3) Red oak.'___________ Quercus velutina. mar- Uandica, kelloggii, falcata var. pagodae- folia.laurlfolia, elltp- soidalis, rubra, nut- taliii, palustris, coc- cinea, shumardii, falcata, laevis, phel- los White oak........ Quercus arizonica, douglasil, macrocar- pa, lobata, prinus, muehlenbergil, emor- yi, gambelii, oblongl- folia, virgin!ana, gar- ryana, lyxata, stellata, michauxii, bieolor, alba Pecan ............ Carya illinoensis, cor- diformls, myristlcae- formls (4), aquatlca (4) Persimmon________ Dlospryros vlrglnlana GROUP 2 The allowable fiber stress in bending for the species listed herein when used for side rails shall not exceed 2,000 pounds per square inch. These species may be substituted for Group 3 woods on the following basis; The dimensions may be not more than 7% per cent smaller for each cross-section dimen sion, or the thickness may remain un changed. In which case the width may be not more than 11 percent smaller If used edge wise (as in a rail) or 20 percent smaller If used flatwise (as in a tread). Douglas fir (coast region)__ Western larch______ Pseudotsuga menziesll Larix occidentalis Southern yellow pine_____________ Pinus taeda, palustris, echlnata, elllotll, rigida, virginlana GROUP 3 The allowable fiber stress in bending for the species listed herein when used for side rails shall not exceed 1,600 pounds per square inch. Red alder___________ Oregon ash._______ Pumpkin ash______ Alaska cedar*______ Fort Orford cedar.* Alnus ruba, rhombifolia (2) Fraxinus latifolia Fraxinus profunda Chamaecyparls nootkatensis Chamaecyparls lawsoniana BFG30387 FEDERAL REGISTER, VOL 37, NO. 202--WEDNESDAY, OCTOBER 18P 1972 RULES AND REGULATIONS 22117 Cucumber ._______ Magnolia acuminata Cypress*_________- Taxodium distiehtnn Soft oim____________ Ulmus amerlcana. rubra Douglas fir (Rocky Pseudotsuga menziesll Mountain type). var. gjauca Noble fix____-____- Abies procera Gum_____________- Liquidambar styra- ciflua West coast Tsuga heterophyCa hemlock. Magnolia Magnolia grandlflora Oregon maple______ Acer macrophyllum Norway pine_______ Pinus resinosa Poplar_____________ Uriodendron tulipifera Redwood* ________ Sequoia sempervirens Eastern spruce____ Plcea glauca, mbens Sitka spruce----------- Plcea sltchensis Sycamore_________ Plat&nus occidentalis Tamarack________ Larix lartcina Tupelo ____________ Nyssa aquatica. sylvatica GROUP 4 The allowable fiber stress In bending for the species listed herein when used for side rails shall not exceed 1,375 pounds per square Inch. These species may be substituted for Group 3 woods on the following basis: The dimensions sball.be at least 6 percent greater for each cross-section dimension, or the thickness may remain unchanged, in which case the width shall be at least 7)4 percent greater if used edgewise (as in a rail) or IS percent greater if used flatwise (as in a tread). Aspen _____ Basswood-------------- Buckeye- Butternut i. Incense cedar*------Western red Populus tremuloides, grandldentats Tilia amerlcana, heterophylla (2) Aesculus octandra, glabra (2) Juglanscinerea Libocedrus decurrens Thuja plicata Cottonwood White fir____ Hackberry Eastern hemlock__ Holly Soft maple Lodgepde pine____ Idaho white pine.. Northern white pine. Fonderosa pine___ Sugar pine Engelmann spruce. Populus balsamifera. deltoides, sargeotii, heterophylla Abies concolor. grandis, amabliis. lasiocarpa, magnifies Celtis occidentalis. laevigata (2) Tsuga canadensis Ilex opaca Acer saccharlnum Pinus contorta Pinus monticola Pinus strobus Pinus ponderosa, pinus Jeffrey! (Jeffrey pine) Pinus lambertiana Plcea engeimannlt Note 1: The common and scientific names of species used conform to the American Lumber Standards nomenclature and in moat cases to TLS. Department of Agriculture Handbook No. 41, "Check List of Native and Naturalized Trees of the United States (In cluding Alaska)," by Elbert L. Little. These publications can be obtained from the Super intendent of Documents, Washington, D.C. Note 2: This species Is commonly asso ciated with others of the same genus under American Lumber Standards nomenclature, but no strength tests have been made on it at the Forest Products Laboratory. Note 3: Included under soft maple In American Lumber Standards nomenclature. Note 4; This species Is not Included under this common name hi American Lumber Standards nomenclature, but strength (feta are available and it Is accordingly Included In tM . (&) The. rope used with the pulley shall be not less than five-sixteenths inch in diameter, having a minimum breaking strength of 560 pounds, and shall be of sufficientlength for the purpose intended. 1910.26 Portable melal ladders. (3) General specifications--step lad (a) Requirements--(1) General. Spe cific design and construction require ments are not part of this section because of the wide variety of metals and design possibilities. However, the design shall be such as to produce a ladder without structural defects or accident hazards such as sharp edges, burrs, etc. The metal selected shall be of sufficient strength to meet the test requirements, and shall' be protected against corrosion unless in herently corrosion-resistant. (1) Because of the varied conditions, and the wide variety of ladder uses, lad ders may be designed with parallel side ders. (i) Step ladders shall be designed and constructed to give a minimum slope of 3% inches per foot of length of the front section, and a minimum slope of 2 inches per foot of length of the back section, except that special ladders de signed for straight-in-wall work shall maintain sit least -1 Vi-inch back slope perfoot of length. (ii) - The minimum width between the side rails at the top step shall be 12 inches. The width spread of the side rails shall increase a minimum of 1 inch per foot of length. The width of the step or tread shall not be less than 3 inches. (iii) The length of a stepladder is rails, with side rails varying uniformly in separation along the length (tapered), or with side rails flaring at the base to measured by the length of the front rail. To be classified as a standard length ladder, the measured length shall be increase stability. within plus or minus one-half inch of (ii) The design of the side rails shall the specified length. Stepladders shall be such as to insure a product which will ' not exceed 20 feet in length. ~ conform to tbe requirements of this (iv) The pail shelf shall he designed to section. fold completely within the ladder. (iii) The spacing of rungs or steps (v> The back section may be designed shall be on 12-Inch centers. with either rungs or cross bracing as (iv) Rungs or steps to side rail con long as it meets tbe general and testing nections should be so constructed as to requirements. insure rigidity as well as strength. (vi) Steps shall be corrugated, knurled, (v) Rungs and steps shall be corru dimpled, coated with skid-resistant ma gated, knurled, dimpled, coated with terials, or otherwise treated to minimize skid-resistant material, or otherwise the possibility of slipping. treated to minimize the possibility of (vii) The bottoms of the four rails are slipping. to be supplied with insulating nonslip (vi) Hardware shall meet strength re material for tbe safety of the user. quirements of the ladder's component (viii) A metal spreader or locking de parts, and shall be of a material that is vice of sufficient size and strength to protected against corrosion unless in securely hold the front and back sections herently corrosion-resistant. Metals shall in the open position shall be a component be so selected as to avoid excessive gal of each stepladder. The spreader shall vanic action. have all sharp points or edges covered or (2) General specifications -- straight removed to protect the user. and extension ladders. <i) The minimum (4) General specifications--trestles width between side rails of a straight and extension trestle ladders, (i) Trestle ladder or any section of an extension ladders or extension sections or base sec ladder shall be 12 inches. tions of extension trestle ladders shall be (ii) The length of single ladders or in not more than 20 feet in length. dividual sections of ladders shall not ex (ii) The minimum distance between ceed 30 feet. Two-section ladders shall side rails of tbe trestle or extension sec not exceed 48 feet in length and over tion at the narrowest point shall not be two-section ladders shall not exceed 60 less than 12% inches. The width spread feet in length. shall not be less- than 1 inch per foot (iii) Based on the nominal length of of length of side rail. the ladder, each section of a multisection (ill) Spread erf base when section is ladder shall overlap the adjacent section open shall not be less than 5% inches per by at least the number of feet stated in foot of base section siderail. the following: , Nominal length of ladder (feet): Overlap (feet) Up to and including 36 Over 36, up to and Including 48_______ Over 48, up to 60______________________ 3 4 s (iv) . The extension locking device shall be designed to- withstand all load tests. (v) A metal spreader or locking de vice of sufficient size and strength to securely hold the front and back sections in the open position shall be a component (iv) Extension ladders shall be of each trestle ladder. The spreader shall equipped with positive stops which will . have all sharp points or edges covered or insure the overlap specified in the table above. (v) (a) Extension ladders may be equipped with a rope and pulley which shall be securely attached to the ladder insuch a manner as not to weaken either the rungs or the side rails. The pulley shall be not less than 1% inches in removed to protect the user. (5) General specifications--platform ladders.AiY The length of a platform ladder ; not exceed. 20 feet. The Iength of a platfonn ladder shall be measured along the front r&Ufrom the floor to the platform. (ii) Minimum width between side rails diameter. at platform level- shall be 14 inches. No. 202--Ft. n- FEDERAL REGISTER, VOL. 37, NO. 202*--WEDNESDAY, OCTOBJ 16,-1972 24358009