Document NegKVXvXJYLDwv2BEaLOLBBqE

ssjp LTA'23565 :, : L jllfliifafrtftf'n'A' ** V l ih1- Mi rti.^A /^c*wrii1i It ii'dty ,^-w' L*-od IndutlrUt Autxlotlon, ln. 292 Modiion Av*. Nw York 17, N. Y. Deccnber V, 19&2 SUBJECT: HOIST COOTBOL To Members of the Lead Industrie* Association, Ice.: Attached i the first detailed report of a case history of a successful Installation of lead for noise control. At this tine it Is strictly for the Information of etchers of the Lead Industries Association, os the material has not been cleared for publication yet. Me Intend to follow this first report vith additional cose histories of other experimental Installations In order to build up a background of practical field data for use In evaluating and developing the market for lead In noise control. We are con tinuing to encourage experimental lnstailatlona and have United funds for partial subsidisation of such Installations as Indicated In the attached report. We will velccce Information from members of other opportunities to work vith people Interested In nailing test Installations vithln our ability to do so. Very truly yours. RLZ:nk Ene. Executive Vice President _.4 *T~*r*'rf4ri` 'f|"- ijgwaywurwy'i L-IA 23 56 6 'To*--'i': ,^.-_:C." iCSisfti1 ^ i'^lUlL.'b fal _v>v ./;;.w ---Vp Vv,.v. ; /: . .-. . :/-V.^:.: ,-,;7 .-;.V trod InduttrUt Atioclotlon, tnC. 792 Madlton At *. N.w Y<k V 17, N. T. Look Ahead with Lead V. November 26, 1962 LEAD FCR NOISE CartROL -- CASE blsTORT # 1 Poise laboratory at Franklin Institute IKPCRTAKT --- For Internal UA uee cnly. Thl* material la not cleared for publication at thia date. Sirrvirvi The Franklin Institute, following the recocmsndatlons of the LIA, has successfully soundproofed a critical facility vdth sheet lead. Teats of the soundproofed room, a noise laboratory, show that the treatment was responsible for a li db improvecunt in the wall and prodiced a noise reduction of about 15 dS as finally employed. The project used about one ton of four pound sheet lead thought for the Job by Franklin Institute) and a leaded X-ray door supplied Jointly by Bar-Ray Products Co. and LIA at a cost of $62.50 each. Testa were made by Bolt Beranek and Nevnan at a cost to LIA of shout $1000. Hlstprr and Problem In Septesfcer 1961 ths Franklin Institute phoned UA to ask how lead might be used to quiet a room designated for critical noise studies. Ths roam (ses sketch 1) vras one of a mrfcer of workrooms separated from a noisy general area. The building was an old two-story high structure which had been one large open bay with exposed roof trusses end no floors or internal partitions. The work rooms had been put up of 1/2" plaster board on either side of 2 x It wood studs and roofed over at a ceiling height of ID feet with 1/2" plaster board facing on 2 x 6 Joists. One wall -- part of ths exterior building wall -- was of cindsrblock and ths floor was concrete over earth fill. Cn the opposite wall of the work room there was a door opening to the general area. Electrical service, high-pressure oil Unas, and air conditioning and return ducts pierced ths walls. more - h ",ji,w* yxi >* ?Tr '" ,,yyTy^AO' vmwm -y*'** T^yrw N 1880.01 . : . LIA23567 Franklin Institute -2 November 26* 1962 The work to bo dona in the room is classified military research* It called for detecting mall amounts of noise pro diced by machinery within the room* In addition- to the normal noise load eapected in laboratories, the general work area and other workrooms nearby housed continually running equipment, light metalworking operations, and occasional operation of a very large air compressor. Action taken! After inspecting the room, LIA mads reccccaendations and these wore followed almost exactly. As a result, the room was lined with 4 lb sheet lead at Franklin Institute's expense and an X-ray door with a 12 lb lead core was hung to replaoe the hollow door originally used. The door was furnished Jointly by Bar-Ray Products and UA. The finished wall, after modification, consisted of: 1/2" plaster board on both aides of 2 x 4 studs, 4 lb sheet lead borne by 3/4" furring strips positioned on the studs inside the room, 3/4" plywood on 1/2" furring strips positlonsd over the other furring strips. Interior finish of the rocn was acojstical tile. The 3/4" plywood was not added because of the sound problem but was needed to bear pipes and moderately heavy wall-counted equipment. The seams in the lead were made by lapping the sheet lead and buttering the lap with a leaded plastic before the l/2" furring was nailed down. (Sketch # 2) The cindorblock wall was treated in the same way as ths other walls. At the ceiling, 1/2" plywood was nailed up inside the plasterboard finish lrd this was faced with acoustical tile. Ch top of the Joists (previously exposed on top) they laid 1/2" plywood, tarpaper and then dtspod 2" of dry sand. The only major departure from our recocmondation was the addition of 1/2" plywood on 1-1/2" battens to the outside of the front wall of the rocn (where the room adjoins the general work area.) The space between the original plasterboard panels and the plywood was filled with (tripe d sand. All of the added construction was footed on foaa rubber and the wiring and piping entrances ware well calked (though we did later find eaao leaks around tho air conditioning). The piping connection for high-pressure oil is through flexible pipe and the puny le shock mounted. Rertultat Ths Franklin Institute agreed to let us have Bolt, Beranek and Neman test the roots and publicize the results. Accordingly tests were mads in April of 1962. BBS used a technique which allowed them to estimate accurately what the Tt of tho partition would have been if there had been no flanking paths. It is important to note that the partition tested in this way was the wall we have recommended -- not the front wall which had the additional sand loading. s-JLW.! "e ' O'* o .- = ` ii) I t hIA 23568 ,' . 'V?'4. - .-- ..- a .] Franklin Institute -3- November 26., 1962 The result a of the test showed that tha 9 frequency averago of the laadod wall was 46 <b -- a 14 db improvement over the dryvall construction alone based on BBh'fe existing data for that construction. It la Interesting to note, too, that tho leaded wall achieved an average of 45 db In noise reduction -- an excellent record in view of the fact that most field erections of a partition fall to case up to test lab results. The test results are tabulated here! Frequency 125 170 250 350 500 700 1000 2000 4000 Average r. for drywall construction (from BB!J files) * TL for leadsd wall without flanking (fraa test) db 15 30 20 33 25 36 29 41 34 45 38 51 45 55 42 63 42 62 21 * . & Noise reliction actually achieved db 27 31 35 40 45 50 60 65 50 UA's primary interest in work of this kind la In development of practical products and applications. Froa this point of view, "customer satisfaction" and tho reaction of the people who work on tho project are perhaps as important as tho demonstration of the technology involved. It is therefore quite gratifying to note the reaction of both Hr. Harry Ripple, Research Group leader at Franklin Institute, and Hr. Ranger Farrell of BBN. Hr. Ripple, in the course of a discussion about what additional atepa night be taken to quiet the room, said that he doubted whether any further work was Justified. He said that, "Our primary mission has been accomplished. We have a relatively ouiot room at a reasonable price.11 Hr. Farrell, questioned about how this room compared with other critical acoustical facilities he has firs*, hand knowledge of, said that it was not as good as a laboratory built expressly for the purpose, but quite good enough for the work to be done there. Then ha added, "Of course. If you compare It with an exocutive office or semething of that kind it Is fabulous." Respectfully submitted, BFsbc /Bruce Fader tJapager, Technical Services ;\ !' i * JPf.'f '. *JJ* Ul MlM-fo.' I, J.9. . LIA23569 : .-:'> -j -:7.h >'*'.''% :-- . r~v>~---. Vs . .' -T. ........... ._ Frpnklln Institute gjtjwpwy- LIA23570 r. yow i . _ -K' .; - : . November 26, 1962 FuRfilMQ "4 it. SH CRT UiAD t/KP^RO ^.Sc a USD XT BATTO*S >'kA. " iPoRHJMq PUt V/o o d Foe p|Pi0<i Soppotzrr C*?tGlMA\- /i'uASTEaeoA'Si) OM 2/4 Vooo t6TU0S <&" o.c. ACo o STiCAU MODIFIED TUi PROMT WALL Z LbOSE. SAND OVR. T7Ve.PAP*S^. >.V.-T'^ '~v! 3 ^ ONLY 3><Wt AS AODlFieD M^ovL) -&irr \'/4.* Fo r s j k JC* OJTS>PC. WITH 'llVCf RM*SH 4 To mp c d s a n d '/t PVAifeR,fcoAR.O tyT PuTvVooo Ao u 3*t t c Ay1 Tiu FiwiSH CLIIIMG DETAIL LEAD Sk e t c h *2. EEAKiKUM INSTITUTE* CASE HlSToTC't' UatvsTfiJSS A*SSU. \\Jz j&>'L '''TfevO-; , ' ?VyH"v* i^.! 1J Jij|K\\ y-* ?jyp^T *nw^u :- J i