Document 2Ewd0OeYgw5rVKneOr72gDOr

PLAINTIFF'S EXHIBIT GF-2268 Meter Vehicle Law tightens stopping standard Truck brakes face stiffer regulations hy Chet Cunningham If you aren't up to dal* oa happen1 iop ia tb* field of track brakes, you may not realixe that Motor Vahid* Safety Standaid 121 ia sac to po into effect oa Stptamhtr 1, 1974. Your track'! brakes will have to put up or pat off the toad. o wait checking your brakes now to sat if they will meat th* stifftr standards of Mopping BUI Team of th* Gray Rock Mv, Raybattoa-Manhattan lac^ says that many of th* currant vabicte*, both tractors and trailers, could ba improsed to opatata aafaly srith the equipment told in 1973 and th* tight er regulations. Some units win meet th* new Mopping law* caaily, white ortnn might have to b* scrapped. Standard 121 contain* a number of requirements for th* performance of air brakes. It ipacifim tranimiminn dm*, which is th* dm* required to build up fiO pri of air pressun in th* brake chambers at measured from tb* Him moeamant of Oa aarriet braka control with 100 pd of air prawura in tbs reservoirs. This i* aat at 0.25 sac. Reteaa* dm* ia specified a* from 93 pai in tb* braka chambers to 3 or 4 pai in not more than 0JO sec. Brake retardation force at various air pressures ia also tat. This corresponds to braka efficiency a* measured by percentage of 1 G. This ia explained as th* brake retardation fore* at th* road surface divided by the groat axia weight rating. What this all means is that rip built after January 1, 1973, must have better brakes, and most also win have anti-wheel lockup device*. Problem* com* up whan you con- d*r what can happen if a tractor mad* prior to tbs affective data is op erated with a trailer mads altar the effective data. That* is a Mrcog possi bility of a lockup of th* tractor wheels, which probably would mean a jackknifs wrack. If an old trailer wa* uaad with a new tractor, th* tractor braka* would activate cooatdanMy ahead of tb* traiter braka* and can** inrraaiad maintenance and operating coats. In cunihictint a teat of your own tractorrinater brakes, look for th* fol lowing! * th* tight marhanical hookup and adjustment of tb* foundation braka* * th* ipaed application and ral**** of braka * uneven brake distribution be tween tractor and niter, and between axle* or between braka* on tb* mm* axle * overaQ efficiency of tractor-trail er unit Problems in any of tbs four points lined above can remit in unsafe equip ment uneven the wear, broken brake drums, uneven brake lining wear, innamed stopping distance, and many mote tin-bnk* problems. Th* new brake regulations shorten the required stopping (finances, and this means that more than simply bat ter brakes wiO b* needed Makars of drum brakes my they can meet this new need with heavier drums to absorb the greater heat genanted in shorter stops. The disc-brake makers claim that only disc brakes can adequately meet the new Hopping requirements. Stephen J. Tompkins, president of the auto divisions, Rockwell Standard Co., said. "In our view, tb* real im pact of MVSS-121 is not so much the braking aspect, as it is the impact on th* front end of heavy-duty trucks, th* axle, suspanrion. springs, and steering. All of them components will have to be beefed up considerably to withstand the greatly jnrreasad torque Hamming from th* new brakes and the shorter stopping distance.'* Most can have over half their braking power on front wheels. CJp to bow, moat trucks have had little frontwheel braking and soma Western tracks omit brakes on front wheels of tandem axle tractors entirely. Many brake engineers my that th* new brake regulations will mean that new trucks win have to us* every possible bit of braking effort that can be put on a truck, especially with the drum braka*. Th* front suspensions of trucks might need beefing up to take the sudden shock loads resulting from heavy braking Auxiliary or overload springs, common on rear axles, may have to be put on from truck axles. Body mounts and frame attach ments to chassis may be other side effects of the new stopping dis tances. The truck engineers have their bands fun, not simply srith brakes, but srith most of the truck. Understand truck disc brakes? Mast of the firms deep into the business have been srotking on truck disc brakes for about 20 years. Disc brakes art more of a problem for trucks than for autos. On cars, the discs are usually on the front, where they get good sir cooling On trucks. 71 toex atoouers, April, tars - n* i* o>r rsta r.r GAF 18942 e^akaksHiifeiMSaiC^rf the point of impact, it does not matter ANFO lending end primed with an electric Masting ho hard the ANFO has been hit, is cap at dw bottom. ANFO if poured loof as foil detonation occurs. If the In field practice, ANFO it loaded in into the bole, and col- \ inroatioo is not sufficiently powerful, tbs detonation of ths ANFO wfl] drop ^below steady state, sod die out. ooe of three ways. Fust, and moat common, a "down Ime" of detonating cord is lowered in the bottom of the mnfi win be hit when continuous high-veloctj throughout in length, with a dctooatjoo tea used \ Below a 2-in. diam borehole, the iideof ANFO is so marginal as to be of (yds consideration. Above that diam eter,V^hs foUowing velocities can be sawsold with only a few hundred feet par second variation: 9.000 fps 10400 fps 11.000 fps 12*12400 fps 13.000 fps 13400 fps In a few circumstances, ANFO will detonate consistently N^n excess of 13400 fps. \ hole with one or more ceil primers or sticks of dynamite attached. These am Mated in the bottom of the hole. AN FO is pouted into the void, and the hole is stemmed. Secondly, holes may be loaded aa above, with additional primers called "boosters" or "over drives" added up the column random ly, or with precision, depending upon the practice of the loader. Thirdly, and leas common but mom efficient holes ue loaded with a blasting cap and primer, or dynamite sticks, end ttemmed As long sa dw hole is loaded at least the distance of the subdriUing dynemiw or a dense optoenm, must exceed 16,000; (Expertmen- taboo with two iponam liquid tx- plosives that very high velocities is continuing, arid these may be the nisi priming If the future.) At dw pqjht of initietioo, always at the bottom/in aa axial-primed bole, high velocities will occur, end the per- of/ANFO win detonate at these The distance from impact to d^ wen of the bole is leu then m/tt.. in any direction. Steady state not be achieved, sicca annular dftance from dw point of impact to Aha maw of ANFO is not enough to / ^ ** , ,, uiin, <*, of This is not to sngptst *t)tat them will be no point in the the ANFO will detonate in exhpss of 10.000 fps in s 3-in. borehole, and cue it exercised in wiring, this / probably is the bast method. / velocity. Them am sufficient explo sives and ruQti-ixw detonation to avoid a "dead pros" (crushing of dw prills, but not causing detonation, caused a cast Pentollis primer, whot ty may exceed 17.000 fps, it inith the parades immediately uound primer wiB taka on the initiatiaf ve locity. As the detonating wave travels from particle to panicle, it will slow With those facts in mind, consider alternatives to end priming of holm. If the initiating process could' continue lotUmi wouulld occur. If the hole could when detonation is loo fast, u with detonating cord) sod sufficient detonat ing velocity to keep the ANFO from failing to detonate completely. This phenomenon will continue throughout down, so that, by the time this wave bo fAegwdMed with CcmMi Pprriisnotns., eeppppromorDi- The result is to bring the vdodtim has leached approximately the maw distance bom the point of iaitiMiea aa the diemeter of dw initiating primer, it win have tiowed down to the smady ante. Some authorities say that the dis tance will not very at all, tome daim that the dtance to steady sate win vary with the diameter of the bore hole, end some daim it will vary with the diememr of the primer. Whe ther steady state is reached in 3 in, 3Vi in. or in 1-in. is inelsvsnr. the point is that stmdy stats win be teachad and qukfcy. Not much win bo added to the overall effect if additional boctwrs am added, as they often are, up the col umn, every J or 10 ft Dooweri may not reach their rated velodtiat. since they may not be detonated in excessof their steady-state velocity. Boosters, even if they am detonated with caps or Primecord, can only cause the ANFO with in thoee three or mom inches around them to detonate at a higher velocity. Tbs overall column is largely unaf fected. Steady Kate is reached and. provided the initial velocity it suffici mariar.tbt iHemewr of the bcwhole. no ANFp would bo needed While piaamag Wvbring dw ANFO so higher is mind that them must not be team ANFO in any di rection from (be initiator then the diememr otthe Mrthoia. The answer, of count, is a column of high exple tives through the canter of the borebole, continuing up tag bolt as far ee the ANFO wffi be j Large-diameter detonating cord should be used: 400-gmin/ftNetonat- lag cord is not sufficient to dotoostioo of ANFO from Pre-split ixpinslvst ere, at present. 1 beet answer because most of com in cartridges of 16x24 in. with' cardboard spacan provided to keep the caraidgm butted cad-to-cnd. They am manufactured to provide ooofourtfa pound of explosives per foot of borehole. Although lVtxS-in. cart ridges would provide better detona tion, placing them eod-to-eod premats a problem. One way to overcome this drawback it to drop them down a tube of polyethylene previously. dropped Sub (he hole. of ANFO into areas where they will approximate those of the explosives used to initiate, and without Ion of gas production, so inherent in aa AN FO shoe, end so necessary to rock movement and breakage. Why is it necessary to Bed ways to bring ANFO to these high velocities? Theories of rock mechanics tall us that dw breaking medium of rock should u least be of the nine velocity as the natural frequency of the rock. More complex matters arc involved hem, but the basic idee is enough on which to function. To break dense, hard, massive rock a hard-hitting, fast, brisant explosive mint be mad. Granite is the prime ipk. Moet granite will have a ity in excessof 16,000 fps. ANFO in this type of rock will cause poor fragmentation, back id aU the ills of poorly planned blasting projects. There is not the na tural brisuce for good fragmenta tion, nor ia\hcrc the density, and hence velocity, \io puO the toe completciy asvay-frotnubc new" face. Dy namite is expensive as competed ent to sustain detonation, no increase Once the holes have been charged to ANFO. With vernexUy, or axially, or drerraae will occur. with t vertical column of cxploatvea. primed holes (he low-cist explosive .,, Amm canshspae* IDS IOCK FtOOUCTS, April, IFF* - New le Oer 7tk Veer 77 GAF 18943 wl* irr"inir they usually are ofi the beck, wb* they get little cooling by run sir, sod the brake* do most of their work oa slow downhill rum end under heavy load*. So tome bask engineering rtmigaa bed to be nude front the auto-typ* dec brake*. One Arm committed to di*e brakes is the Wagner Electric Corp. of SL Louis. Wagner offer* a complete line of hydraulic and air foundation brakes. The disc brake for track* of 15.000 GVW and up is an addition to the company's line. Hera an some benefits claimed for fit* Wagner disc brake: e directional stability good stopping without periodic adjustment e raaiatance to fading due to hast or water excellent driver respnnirvtrass adaptability to vehicles using air-hydraulic, vacuum-hydraulic, or power-hydraulic actuation systems Tbs basic design of tbs disc brake offers benefits in perform***, main tenance, and repair, la a disc brake, hem is dissipated torn tbs sain* tutface on which it is generated, and dieriparioo is fastsr sine* the heat is not transferred from one surface to the opposite surface. Soma naaons for this battor htat dissipatioa indude: Tbs friction surface is not ef fected by thermal expansion at the metal, since moat of the surfaca is at right angle* to the applied braking force. Sixty to 79 percent at the friction surface is exposed, since caliper occu pies only shout 29 to 40 patient of tbs disc ana. Thus hast is dissipated dirtedy by radiation and convection without the beat traveling through any mstaL Quick-change linings make marinenance and repair easier, tinea ratal inspection is all that is needed to dotannine lining condition. Kcbey-Hayes, another pioossr in disc-brake development now often four-wheel disc brakas for tracks. They talk shout five advantages to disc brakes for tracks. (1) Stability--To th* driver, this means straight-line stop*. (2) Shortar stopping distances No Dim statistics an available for rack products tests on * comparative basis, but many agree that disc brakes stop rip quicker. (3) Cooler operation--Greater ex posure, different principle. (4) Longer lining Ufa Cooler run ning means longer fining life. (3) Imperriomnaa to contamina tion--No entrapment, self rleening This is just a taste of th* otw thiop happening in brakes. Make your own survey, tod find out what the new brakes and the new brake regulations will mean to you and your rock prod ucts trucks. SOCK rtOOUCT*. April, im - New la Oar 7*k Taer 79 GAF 18944