Document jBqO0BYdbXEmMqX2djeGxbLg2

LEAD INDUSTRIES ASSOCIATION 101 MADISON A V C N U I NEW YORK 17, N. Y. February 20, 1961 SUBJECT: REPRDff FROM "a ir corromoNDW, h e a t u p AHD YCTHLATIBO" HAGAZPg To Members of ths Lead Industries Association: Ve are attaching, for your Information, a reprint of an article vhleh appeared In the January 1961 issue of "Air Con ditioning, Heating and Ventilating" entitled: "Lead-Asbestoa Pads Isolate Cooling Tover Vibrations." This article reflects the views of an Important 5ev York consulting engineer vhoae firm has specified these pads under a cooling lovers on the Crolier Building, 575 Lexington Arenas, Kev York, and vbo has been sufficiently satisfied vith tbs results to specify the* in the same vay oc arctb-r skyscraper at 685 Third Avenue, vbich la still under construction bv* eo which the pads have already been lnd-HcC. Ve are also circulating the reprint to some 15,000 archi tects and engineers. Reprints In quantities up to 100 are available upon request free of charge and In larger quantities at two cents per copy. Very truly yours. RLZ:JRX Alt. Secretary ropy* sewcyy y. -- mumimn LIA2AA55 AIA No. 39 ---1- W APPLICATIONS AND INSTALLATIONS Lead-Asbestos Pads Isolate Cooling Tower Vibrations AL LE1CHTMAN Weinberger, Friemen. Leichtmen ft Qimm ConsuHmg Engineers, New York, N. Y* 'HE COOLING TOWER of the new 34-story Groller * Building in New *ork City Is a typical skyscraper installation. With its three 60-hp, 1800-rpra motors, with spiral bevel gears driving three 12-bladed adjust able pitch fans at 202 rpm and a 6,000-irpm water pump, vibrations are initiated which, if not isolated, would be a considerable source of annoyance to office workers below. High winds, on occasion rushing through the tower slats, intensify these vibrations. It was decided to isolate the tower from the build ing by separating the supporting columns of the tower from the structural beams of the building. A material was required that would have the capacity to absorb the tower's vibrations, yet have sufficient strength to support its 205.000-lb load. A combination of lead and asbestos was found to be suitable. Why Lead-Aibettoc Our choice of lead and asbestos was based on the successful adaptation of anti-vibration pads of asbes tos scaled in lead in isolating even heavier vibrations in such structures as the Waldorf-Astoria Hotel, the Union Carbide Building and other buildings directly over the New York Central Railroad tracks; the BeU Telephone Laboratories, with railroad tracks running right between the second and fifth floors, and in build ing construction above the New York City subway system. Te?ts conducted at Columbia University many years aco proved that lead and asbestos, in combination, had >up< rior isolation qualities. The tests also showed that ingt-thrr they damped better than either material alone. Both materials are easily workable. Lead is highly resistant to corrosion and impervious to water which makes it an excellent seal, while asbestos is equally no'ed for its chemical resistance qualities which assure long-life for the juds. An additional advantage of the combination pad is that it can carry heavy loads, a quality rare among isolating material*. Durability of lead-asbestos pads was demonstrated when the old Marguery Hotel in New York w m razed to make way for the new' Union Carbide Building. Lewd pods on which the hotel had rested for more than 40 GO to \ N 1705.01 <wap*QpqpyglQimk*`>*w-'elp&R^ *uywpr^^9 *** gWWMT LIA24A56 %" lead %" asbestos r * 12 gauge steel ::??:.^x.v:-: Vi" asbestos Vj " lead Rg. 2. folk structure c4 rtoUting p*d. ^A Q m m w -.nH 'ii.i i ' .ni n.i .iin f f t * w i'jm u ju n w m m ^ n n w i i u ^ * w w w ^ . pi m n n . i , Fig. 4. Architect'* rendering of new thirty-four story Grofier office budding at 575 Liimgton Avenue In New York City. steel billets were bid over the pad* to distribute the weight, and the tower's 4-inch angle column* bolted ft?. 3. Padt are ?n*tSod b*^wtn the bato of tho cooling fowr'f supporting commons and the actual structural steal at shown in drawing. directly to thex? billets. Supporting angle columns of the tower were also isolated from the concrete roof by detaining them in pitch pocket* of non-hardening truistic ciNiipound. Pitch pockets extendd upv.ard from the structural beams to y*ars were found to be in j**rfect condition, with practically no coerosir.n or dimensional change. almut I*; inch-* alcove the roof surface. This calking procedure also insures against water leaking under the angle columns and into the building. Lead pads had txwr U-n tried under a cooling tower. Would the jud* be effective--since some of the vibration from the tower would be of much higher frequency than that of the railroads? Since the cost of installing the pads was relatively negligible. the expert meat w*u justioed. Costs Kept 0o* Economy of U'ing the pad* i* apt>ureut when com* pared to the alternative co>t of constructing the con* crete roof thick enough to absorb the vibrations. Fur* ther cost saving in HTretcd by installing the pad*. bil* Pad Specifications , lets, and tower *up|s>rting rolunuis during the build ing's construction frame stage, rather than after the Pads installed under the eoolinr tower are fabricated concrete roof had lawn laid. This procedure rlin inates like sandwiches--two layer* of *%-inch asbeMo* (dared time and cost of recalling the *ts-l worker* and their against a layer of * 12 rare steel. scaled in 'k-inch equipment to install the timer's fooling* after the roof i lead under pressure of ?im> ji. There are ten pads of has U-cti laid. Instead, all is in readiness for the cooling 1-inch thickness in all -one for each of the tower's ten tower to le attached tu its uip|orting columns, alreody r supporting steel anrle columns. Surface dimensions of in |4ace, once the roof was r<m|fcted. th-? corner pads are $x$ tnche*; those of the other Absence of vibration* on all floor* of the building, pads, naturally subjected to greater load, are 8 x 14 even when the coolih* tower I* ojtcrating on windy ? inrhea. Thus, total anti-nb.-ation surface of the ten day*. is CMilfiKf of the lexdasUsto* jiadV ability to pais is 93$ square inches; pressure is about 22o p*i. absorb effectively the cooling tower vibrations. o. Sylvan and Robert U Bien. New York City, were the bwtatatio* architect* of the droller Building. The author's Arm The ten pads were laid directly on the building** was the consulting engineer*. Owner-builder w*as wide flange construction beams while the building was Sam Min*koff L Sons, It**. Tads were *up|4icd by John still in its construction frame stage. Then one-inch F. Aberuethy and Cm, Brooklyn, N. Y. KegelsfeS fey peewUslaa fr Alt CagJfUaff, Htaflsf *4 tf UAO INOUITBICS ASSOCIATION, Itl M4ia An im, Mw (Prlitad Ja tf.lA.J Jattary, I Ml Tart 1?, New Toet isyipyw.'m 'WW 1M* u *MI V f