Document qdOQNdQ8rjqJ7EJJemJ7m7XKk

235 23LI A . - `' '-=- ----rihi1*f*i*ii lYfimrii* *'l/if*f*---:~4- ri'- * *-*'** * *r.'...^<s, * ,T~'^riii*~fihttii~~^iiT1ti,i`t'i^r~irt i' i Here and there t At - -/n/ernafiortaf Co',tr**>'(* ow l *>d The Second IntriOfl'oiMl Conference on Lead u lo l4t> pM<e l Arnhem in Holland |Sc 4-7 Ot'ohfi 190i The (o 'k Jm'i -lead /'rvrd dJo<* af/he tV A double drt itf bus cou*d be do*en into |li PUC'l 1number TV stud*o at the Wh te Cd| in London through <<%1 conference, wh*<h was held in London irt 1%?. was the piiri o(M*rat* if doos about ft f| high b| tilt w*de tr'v tun i tt(uln(]thr'r(jnbf Mile dubt that the second pineitrd to g *e attest lor taige ob|est w >11 U- cqujli, to The trchn.caf trtvont and work* rs*1s Onoo ae. all too rommonlf, a weak spot m the sound a*r b'<ng arrang.-d m thiee groups -eaMr sheathing. lead insulation al'0*di d by warts, but ttese docs aie designed er.. J baltet-rs, and QrOrMl *pp`iCat'n> of trad futl p*n<- to be ji>el!r<ln bann r agamsf t ttianeoul no.teS, which < uli't tan be otiUiAHJ liom the Lrld Odf'Opn'tnt Asso- must of course be kept out of the s'ud'O when it it >n use. c-aton. which * organizing the iontcien<* on behalf of th* In the construction o* the doo's there are two Chaiacter* (v'opfin Lead D^irtopmrrt) Cotnowtlff st.< 4 o* part.c utar sign./.cance >n atta<n*ng a fvgh standard of sound insulat-on F.rsUy. lh edges are d< s gned so that G'-Iipo* -1+4J A*e/ lot yJChft live/ are welt iealid when the doors a'f dosed. teamg Ya* hi buiidrfS on H>r Clyde and fltr^wr jr* rreet.rvg the no 4-r gaps through which no*se cou'd easily pass g'Owng popular demand lor craM o* both '(tats* And S.-Condiy ,- a la,rr ut ead sheet is mcorpoiatcd nto 1h 4 m tpecral designs W`th iwr adanc*d methods vf bo.tdmj th.<*ness of th" doors Lead, because cf <ts mass and ina". those u^* d in Jh- past The designer wants keels cf l.f*>pness. pro.*des a more eff<t e Larr.er lu ait-bome accord!*- weight in 4 shape That can be taxed cleanly to the sound than a (empsiable thickness of we-ght of any other ho'i n in a ti:Qh standard * t*".sh The yard rrgu-res a Sheet . g* nr-*af use (see f *g J) .rt! ng that a't e>* as rar`| jt potv *j> icAdr 1o> <t- tirl^r 4A(( to i,<i'j,'*, ro lostlj UI:Ou >n T." thing a-d hr-1 Mi'*- O'- ng B us-ng up-'O dat* foundry t*-<h Veaf J*f/? ft g.y Tf ir Thv* wood cow.rg shewn .n fig 4 has Cu t* a h>sto<v m N.|J.N. M-4d Can MW'r Ira' *n Loth krets wh*i h t*ad (ia.nl hj |.:.<ted a 1 -rta n th.iugn sOrr-ew-hat prior r 3 at *ep* t tan cast o' at 4 *}** of* >'! < asf r* no* part ?hr* heart, w fh *fs tu-j'd >n fhr#, (.Ja.ij. sur- mgs j*x- ! A-t*'. chain #nj p.miitvop*1 a-d weight !o`*r- n'Ojnted hy a liivkrt curia.n ng *3j *s and Swi'Ounded by \ <"(! ' * : *.'.!< loth th* des-Qnrr an<J the Lw-ider To Q> t good (O'l'n.: o.e tir w- g**! o' in* cas'ng tnc Af'OuS Ibr".t Cl 1h t'aC-tor.a: t'a-J*s nt th* d striCt. fepfi-vvi'ts thr ffi*r-gu<} Ty^e ft * ts -In c * g *. in a group mctai *.s<l ct known iO''-p0f! o", a".1 >s frd to t*\c t*1 n-ne masks. ia`.*<J .n \tc.r. *,4*0 *o uinament the n ou1 J i Cfi< h.n q,,-i mat u . j !!M* .t*e no ith nr S'rand i a*.C'* *it Snm*rj'* Hcui* *n bonder* when it cf-** t.-'t*. wnch coohi *Vil i-c-* r.~*, ?h- rr-grtf t*xt was lebuHt 17M wh<*- a un'*'1 mask 1. presents the ',<* Ih<- ceMre <r***''j T.r ir."'* .!*vj**i ar.J-n o*-.a' 0* van. fia;***.**! L> e gtit ol`**rs rry,'*s* nt ->g t*e Lngnsh Va }. ; t - '*-.."**,' . - * f. : t ? * -' n * Th-'/* Vr-M, w. -,. T.v,,:f M.-dway. Dm. g >< ilhnjh i m- ly* < a`t * t' * , nt t--ac hod $<- r-ln and f ,e Accv'.th- ii-|if' I on r' ;i-j J k.*. ^ 'o* <;*n n An pr,g<j,mj ct thr Tyne rr.isk was u n -(J a', a front sp.-<e tc* B'jnd's M vtc of far A.Jf n -fir ' T y nr p^bl shrd n rt.r- v p*rfc.i*-.1 rC-ct- <-. .1.*.c*rat G-> n *h 'K* , ' fi ^ -d*-' f'Si thru !* fltl^ j fa*w;jvt *. i '.n`i i a**d LoCkSe..r* li'.'h to .'1 '< '.m IN( t -i.i of C .1 n * t.o./j ng - fliiit*: t-"1!4. w.sh ng to H i .* th* ?*aj t.'.-.-.a fi.'. ' * r.j.,ng a s gn h a'- i On * o*>nJ t*r a ; g. an I to f.n '* Cj.* r th*- ri-j'yt <* h.s snr.p. f,.d .% wood CA'. "g mads* fro<T a?t tv hrr,n!, rftio*.-r| f Ijo-ta'*- M o >'-4 thr th*- -g'.i.i'-g `or t'-.s bu'iiOse he aS used a wood In < ar o* t*t-f- g:avt h.!`t rf t pj*?-i .* mjrjv.ng t` th. l.-ad as j pr-rtn s co ofhon Subse- I'ta* t'-i- il.n^nvori n< lh* a-*tl r.d th*- ho': tho-:d t * qy Ptly the < if mg p.u N.-d -r.fo Iff l*an<f y1 Andre* Jtnd Njb.f<! to V'ar..u Wdh *h. t*u;:\ J*->.gM- Ihr- found* o` a wr i snown fa* ** jst p* -r -g fum. and mi'.m ntorr a^d " oft- to ho-vi thr ba 'j'-r t ' n Vi " t' r I ado'nr.J h s uffaif's |.* m.s* s u't ' * . ntly when it .li'V g'aN* jt* ', w-o.i * Nt 1<r*g t on tv 1- tar was wth.lr.iAn into th.- ri-ci jit.ui ic-o"' u* 'nr company's -Vipr-.l (,-a*t ulerkt TIi-n n'.ikr n at 9 e* tiHpi a*- i `.u* * s \ rs. H *dsor* a*r*J And'** Be*d L'-l l ortrol l>* n *3* t *i>i-fc inij-uManI Thin .. *. ard thr intt* Du.' *'U -Is i f* t n - idab<*t t JO ,* ars ipnsu'i Im mask had pC'dt Or; O* iu-Uh'i- han't, rg t.i^i' t r* *n '-* taNt ti!OC be* n well i * *Ji -1 wth I* ad pa **t tor prot* c' on. and when Can tontr.l ulv Qu'nVf f' fh aj* of att. i*-!- , M*ipp"d n< th. <l r| g*i*ne >.*- pj r>| dnwn *o the bare wood. f 0* the `t In v ' *yat. t. I.vt.al c o n i o ' a lead 0 t* cast ke* I t emerged n 1 e'i-,t comJ ,;on Lr'ad pA'*>* does *ndvrd mo*e tf<an o'l-it-t I'f -t c*"-o`nicN At the |id m ho*t ho'e g tf la*|.ng pin?*, t os di}1trig, handing >md f,*i Nh-ng as wt it a\ t-^ tf * tup-f>t rjual*ty o? Iht ' |ni.dort f q ! \**u .n % on* o! a batch ir,r.!rr R\-J IrjJ /*j-*r t f j* ruo/caa i>l w *.-1n mad<* b/ Al* 1 ai.dt 1. T igu^Nfi*-- A Co Hd G^a n In the fate *1 ni yiy < hang* s that l'*c taken p'aci* in point gon tor the S` amaNl* t ?6 Hangi 1 t lass t*tinolojr in fei i-nt >< ,*r>. *h t* I* ad ami *< d trad rtmam Mipeftant o-gmc nts, parj-c ylaity tor punting p..nts formu- lO'Mfo'' -/ */i* j t < S '.'f hf l.ii**tt tr g'*" .1 gnod found.it.cm to p'utrct. re pa*nt coatmgs. A new fr sjaurant m Baker Sdect. I 0'<Jon ta ' d t'**> Tlx- lust inhibiting pfC-pi-Mn c that aie inhnen! m ted lead H00V. I'n* an.I Smknr. It liai a maiketl in<t.idoa<-lf m t'-M pamls meet many need** today as in the pat 0 ptoh*Ctmg ait. Ii.tr t ts Li nacd Man>s< h A part iters t,a- used dec o*a Nbi-Iwciik for CkriiupN the steel ia*fway bulge shown in t<vi* motives t'nougtiout that are di i**< d Iron' 1h* f.sht f<g 5. wfi.fh crosses the Mt motorway extension near mins* giar implied m the name. Thrsr* indude bng*;tl# LeiCestr . lias t* en pnm* d wth 1* *1 le'd pamt (Photograph (4lt*uii tJ floati mount* d on a ti ak panel on on* ot thM na'. n supplied liy U'llt'.h H.i.t Ch rf Cnnl Cngneet, London and (.ch .ig f.es t*r ii.nd limn 'rnti-t on jnofbei. fof.dl.md Ri r on ) Tti*' lo Jri'n} 1'. (>*,i.*nn t. 1 a th fast trad N.nki-fS *s*`e f <g 1* J tor H. > purpose t<'" 1* ad ,. r * *. * . ,ti. no liss l* r(e*.i.'*i V -iU't / <`Act /n'.(S rad'O rrmfro/ * P*i t-. 1 than r. tlren r i>?n.,il ! , Aim t> >n t*n* ot the re,i* ktur 1- *"d mM* I..*tin * | owned iiiduslrial Itu* k S .11 b* mg anji' i at.*ns of ** Mit a to re Ai .yhi n a rn j.ar t term and us* if in G*a* Or f.im (01 c'c.vi and eft.c .* 1 :,*echant* .*1 r .v>r **t ao'king < omn.. n<j 11\ uvr han'V.nrj Wilt* n spert.yiul.lt g'owlh m the number in uv< H ;i ' y<iw."'r (i*ywwtfue**.1 t"-v*<|.crk *.yigwj'i ~~*T,J'>.f*.r,` .V.Hii-itii.*r Ki+i^iAC-- 4r Jio the *anrtr of purpnes they tare, 1 it not tuipotmg t* at rchnements tuchasiad.OCooltolafebringmMorluced * j - HfrS o! truest operating Over rv'atui-ty targe a teat 7 hr uCV d'isef can b called up hf the control (OOm < any I *"f, sn<3 be directed 10 bo or*t ch >lhcul having to OOrt back to a central pomt 7ho vA.rv Mme, recreates " ciency in operating the truest and. of course. Cuts * csti. Hunood Mining Ltd Gat thi ad operate l(-n Stica*uC (ork-Ml tucks and (no (UctfiCJ't by this meant and asumate that t mates a ta.m^ .n drivers* time ol about II hours per truck lor ea< h 8 hour sh.tl (tee ftg (). AufomjJ* ireftii^e Jejeclur A.to connecting tead-oc-d LaMer-es *<lh mining it the aromatic methane detector manufactured by the CnQl-th l>;!r.< Company al Sljloid, whim hat been specialty approved by the M-n-'.Mr of Puavf for use in coat runes -- s*-** F.g J. Bc ng computed automtl c. the detector can used fc untrained opeat'.< t It r< asv' s the amount ' * - .rtt.ane In |h. a f tg The r.se n tempi. 'j Hu 'C caused c henuCal act-oft Let a * * n the gas ai- J a < ata;y t1.'*h<ch it ``s'-.d o-n to a ft- .-r ocoupV A e'a*m <s *;*o r*o- * J-a that l.yMs up a hi n ter t v~< e-.**.i* y n of milh.v'.e <i * j ' / <' rts a |r--<J* h-im-m J juc.'U'f C"> t ` e a i ght O* the do>. ifld^-'.g *\ !< j -1-.k >d butler, i -.arr p.yts. C"'r 4 lb The p. i n a lightM-'ijM i , stftrne c ave spec <a ' d<-s gnrd inp cable M: c uj*s. *. 1 g ./s 4 olt *<r 9 hou's b< or, ^ d.rg a recharge ' * *e p-r I'fr.; ~Pc*<t tv a i!fr *" of ft e mot' ad.uncid s M-ia o -. if* l*si iUi'.iJ thr j 'Me-on. 7rent tO'M ot Shr !,i*n Ii- * A Steel non in .det the most up *v J V< ? .. . . * r J* n ` * * " '* * ; and a * continuous cast ng p ii* t Y hr *our r- ic hi ftps r *h t plant-- |-e f-rsi to s, pi ,< z> 0- ;-* f< 'i a < o-ir n- <i` ( C Dg ng n' 'I -and 1". ' 1 -t *_ i < s u'e A 1 Osn J u"e L u-ld.ng WO Ly WX It T r-t ; a'..) j rin p, ' fT Lu-'d-og l-v the n a o'* .< rsa-- . -c vt-uclw'^i rowing Cif^l lu-iy Jwilmra* t '. < / .< *.r>J -ft the UK, and -i i ,is. each abo-t 10'; tr -,J c* saff-ng Imglfis . t*-r. mdi pcnd rfy dr-.i i % .it ft:** r.n-ct. r.Q eo-J f- pc r SiiH'y -f-.f. . he rn ^ Ai-*s s-?.^'.it-crt>. i* < h a is nsta; *t I j ft"J-sh |r,sv'-nt . r C-ui*-nd4 rv C-b?< . ?. inr v'poraV ai 11 tV .eg o , .i U ut s* athr-ii r VWO ;dt m iength. ^n,i . v* .ii ti i .t < a'.ih ft? 0 r VO jrUs.fiy8shoAtltV 3c u r ut.*< s .mu other s * Ihr mp*or rouni l;iii r i *it T r- ns *' the cal h-s are ."fed ahefe 1h-y r*C%S i ;i.if - ->n v.n'N in tr<e st'uc lure < alio* fee the posvlvMf on. .. n t-j Id.ng selMrmi-rit. J 'VJpO'e- (/rtdera f" t< . ,>f m A ifsd sht ath <l '.iilj-iMt.i p t* i.'i.i t.pe i aiiV, m one length If W>) yds lonji I' is Ij' i n sh.piii o the Uh for a.l und< r- nater link hrtAiii t*n 'amt-. i>* S-nQ.tpore and Pu<au (t.'lom (ftrshnuti r l-.lunOl ( S ~ r>t .it in Mu construihon u' iuK l a c able is a : ad u1,*'..!- i.un.n to (he mgre-st t mo .s Iu m*. and this is fhi n..un u>* t.o`> of the lead- thealli* m;j A special rcquii< im nt, Aas M- t.on ol (lie cable J'jiins! th< usk of attack by Mm- ten Jo .1 small marine a- -- nn>| (hs a as - tune mth an uuti > .. i..|iiiiig (if i upper l.i. p and double a mi- .trnui.icrg srr.e',1 -.> (!> compounded jute jfn. f -; * shuns tin- i *<g < u-ii :T <Ju.su into the ship's h.-. rs It. I.h. it- v ! - is m.rl T ii 1 t!.!-ivj<ol.rtion *>' 1*>i , (tin i- r mini ?,7S{' yds II . ali'e nas tc ' il <-'hi the ho:.I (s< e -i ju nt * .< 'oje n I * 'he tiiitish I'nst .liunat - i .stile* noil /.as us- il fur llm puipnM-. WF*iJt "TO j .4 a a '*; i ... ( -- '--Z M s ,- 'V-- 7\-' ;> mcfjj mi Mif WWUH.i l LIA23525 asneaf^n i niyf w ia ciW *i> ,d,, imr>Aiii.a.' Dispersion-strengthened lead 3 The Mcrflenf <orro**on resilience of lead, recognized for many centune*. ha* been used to advantage in wide variety of application*. Furthermore. the metal's softness and mafleaMity allow it to be worked mlo a multiplicity el shapes With little effort. For certain apolicalton*. however, <t would be an advantage if the general mechanical proper* hcl of lead, and especially >ts creep and fatigue prop* ertic*. could be enhanced without reducing it* valuable corrosion resistance A new technique, known as Disper sion Strengthening, promises to bring this about. The strength of metal may be related to the esse with which the atoms in rtt crystals will move, relative to one another, under the influence of an externally applied stress. K this movement can be hindered or restricted, the metal Kill not deform so easily and wH become both harder and stronger. One of the traditional ways of strengthening a metal Is by alloymg. Here, foreign atoms are introduced into the crystal lattice, and these by reasons of physical size, energy considerations and other (actors. pro*de obstacles to the movement of the patent atoms and. consequently, the costal distorts less under a gi.en stress Virtually no pure metal is used m any engineering application today; alloy ing is nearly always used to produce better mechanical properties. AftOf-ng. however, i* not ent-reiy without its drawbacks and. to Circumvent some o* these, the technique of d'SperS'On strengthening has been rvplored. Here, fine particles of foreign materials are incorporated into the parent metal, by one of a vanety of methods, to g *e an improvement in oroperties equal or superior to that p>o><ded by conven tional alloying. A paper by Roberts. Ratchfl and Hughes' mentions the improvements attained e.'th dispe*S'On strengthened aluminium, nickel, copper and other metals and reviews the application of the technique to lead. The various methods by which small particles of foreign bodies can be incorporated arc discussed and the introduction of lead oid<\ PbO. by a powder metal technique is considered to be the simplest approach. LeneP used another metal--<opper~js the dispersed phase. Hr loot advantage of the tact that copper is appfeciahly soluble iff lead at elevated temperatures uuf virtually insoluble at its freezing point. Melts of lead, containing copper, were prepared <n the general range $$0-1,000 C and then a fine stream ol the molten alloy was 'atomised* by a jet of air. More than half the parities of the resulting fme powder were less than 325 mesh (t.e. 44 microns) and within each frozen droplet were tiny particles of the second element which had precipitated on freezing. The small size of each lead droplet ensured that the particles of the pre cipitated phase would be in the second order of fineness. On being compacted by mechanical pressure into a sot.d block of metal, (he particles of copper were uniformly dispersed throughout the matru In this case the presence of otygen introduces a complication. The fme lead par ticles. before compaction, sre lovnd to be covered with a f.lm of oiide and. unless this is removed, particles of lead oiidc become incorporated in tne final product and affect its Anal strength enj ductility. In the case of the copperlead powder, Ihc o'dc can be almost eliminated by healing to about 300 C m a stream of hydrogen for some hours. For his tests lend eibudod the powders into wire form by a hydraulic press, at about <0 : 1 rat.o, using pressure in the order of 3C.OOO lbs m. The products were near to the theoretical density. The mechanical properties ol the wires arc given n the table below, the average particle diameter (and the spacing between each) beng calculated on the assumption that all (he copper particles were spherical and of uniform size. Table f Tensile properties, orygen content, inWrpartrde spacing and averag* copper particle diameter of leadcopper powder eilrusions Coper* <oeiit wt. X TewsAr ilifA^fh * ** (a) at receded COUH > uoe fine as saoo 11 Stco II MOO it r?oo (b| rrWcrZ cewsa 0$ 3>00 h 0> 3700 X1 4300 SO MOO at 4300 (kxiqationOir?** en t n HI- i CM It 040 90 0 04 3 043 47 9or 42 009 3/ 0 0S 44 0 03 34 0 07 Aw m Spacing between p*rlKbt Arerape ynlKto diameter ISO 141 1 30 1 94 t 17 0 033 OM 0 41 0M : 4t 143 1 34 in 1 14 03S 033 0 31 0 41 0*4 If the ultimate tensile strength of pure lead is taken io be about 3.000 p.s.i., then tt cen be seen that the introduction of the dispersed phase has made an appreciable differ ence to this property. A study of columns 2. 3 and 4 in both halves of the labte shows that the pretence of a small amount of ode both strengthens and embrittles the product. Table 2 shows the effect on the creep of lead (at 2$ Q of adding 0-55% of aluminium. 8/ comparison, it should be remembered that the creep of nearly pure lead is about 1 % per year at only 420 lbs. sq. in. at 30 C. Tab/e t Sliest 16 in.* 5000 3900 noo 3000 Creep rate \ year 013 o?4 040 1 is Duration Ol teat hov'S 1300 1174 1000 Specimen faded alter 700 hevn later worl hat shown that systems containing discrete particles of metals whi:h have .'datively high solubtlflies in lead a( liquid temperatures (e g. Sb, Ag, Zn or Ce) ere not markedly superior to ordinary lead. In particular they are thermally sensitive, end these systems do not appear lo merit further study for the time being. Dispersion ol lead oide alone cen also produce strength ening and the lead lead oiide system seems to have advant ages over other systems and to offer better promise of industrial eiploitalion. The amount of oiide may be con trolled by varying the particle size of the feed powder-- which will usually carry a thin Mm of oiide on its surface-- and also by further treatment of lead powder, in a ball mill for etample. Ettrution or rolling techniques can then be used as beta's to obtain the dispersion sbengtnened product. At onetime it was thought that there was a roughly linear relationship between strength and oride content, but later wc.k tqgeits that the nature of the dispersed phase and its degree of dispersion arc more important than the actual amount present ErWusion temperature itself has an effect, and it is clear that the higher the eMrusion temperature, the tower the strength of Ihe product. The dispersion strengthened materials show a pronounced improvement in creep properties, when compared w.th ordinary lead end Tabte 3 shows some figures for dtspcrs:on strengthened lead. ** AAntfc. f\, . f |i*'i<f``ri OS I *1 $( (0S7j 1 LIA23526 formed Irom lead powdcf having an average particle ll/a of I S microns and an side (PbO) tonlent l 4-30%. TaWe J Creep rate T*mp. *c Sr* p sk 41 10?4 2000 XdO M 400 1000 IMP Steady T4*l slat* duration (rtfutt oi \ff* last (Kit) Tola! eOngarion to tr*l % ON M2 (M 1440 2440 tlOO 09 nnt haclw'rd 1S not IrMtueod 021 nof fractured 1 44 n1 M004 2tl0 1720 244 0 44 nor fractured 3ft broke 1 broke By comparison, the creep rate lor ordinary (cad at 4$ C under a stress of tX00p.il it in the order of 2,000% pci year and fracture would occur in a few hours. ., 4b., <4', 4 jr<j lltl?|siltl?lMl AfipJrctlion ofO.S. feed Several woAcrs ha>e listed the possible fields of e*pio<td* tion ot dispersion strengthened lead. Evan:, Huffman and Wainn1 have made prototype battery grids from expanded d'Spersior strengthened lead strip, and pointed out that this matetiat. as well as hiving the necessary strength, has satisfactory corrosion resistance, slightly Improved electrical conductivity (compared with conventional antimony lead alloy used tor (his purpose) and being free from a second metal cannot Qive rise to setl-discha/ge through 'antimony poisoning*. These views find support in a paper by N. E. Bagshaw and T. A. Hughes' who fabricated grids from dispersion strengthened sheet lead and tested them under service conditions wthencouraging results. Cable sheaths may pt oide a tai ge outlet for this material, in spite of the introduction of alternative cable shcalhing materials, lead and conventional lead alloys stiff find edensive use and are almost invariably specified for the most sever* service conditions. The mam advantages of lead are impermeability, high corrosion resistance and ease of handing and jointing. all of which are retained by 0 S. lead sheaths. The improved strength of D.S. lead would permit a reduction in sheath ihickness, which would once again make lead competitive for those types of cable where substitutes are currently being used. Lead sheet and pipe have always provided a popular outlet lor (cad in Great Britain, and the principal reason lor their retention in this market in the lace of strong competition is the ease with which these materials can be worked and installed, coupled with their permanence in service. It is clear, however, that it an alternative type of lead could be provided which was stronger and more rigid in use. and still e c^rrosicn tesistant, then the two types could act in complementary roles to one another, particularly in the building and allied industries. The above is only a brief description of somo of the ctcnsive work now in progress on dispersion strengthened lead. The results obtained to date show eicctlent promise for commercial application of the material and much of the development work is now being carried out by individual sections of industry with specific end uses in view. References 1 O N Rebuts. N A R.it<t*ft and J t Hughes. Render Mtiit- to*ui *?. No 10. p ir 7 F V Leori. Ao-tfw 4Vlj^cr 467. No 10. | 114. 3 0 J I C<an. H K and J P. Warner. MstetaH m Orvf'< ,'g<`eeri.ofl 1S44. Apert. p. IOS 4 N t 040** and T A Hughes. Fowilh International Sympo- tiu<n on 6.ittv<ic 6"ghion. September 1964. Paper No 14. rv*r .' :; : . \^fr:..:: O ; . :- -.. ->.. ~ri ',i niirni r'--1*-1- - ,^" -'^ i^l. -l LIA23527 f. 1 Whtfl painting new galvanized stref. it It usually necetsary to pre-treat the surface; but it Is possible to make a direct application ot certain paints incorporating calcium p'um- i bate. T hit rgtt inhibiting lead pigment hat analmott unique I- property that enable* paints based on it to adhere weft to galvanned ttccl without previous treatment, other than simple degreasing. Some years of practical experience in (he use of calcium plumbate primers in this way have proved that (hey will continue to adhere firmly even after a long period of weather ing. The following four summaries of recently compiled case histories demonstrate that confidence In the effi cacy of calcium plumbate paint is wed founded. Case 1 The eiternal galvanised sheeting of the steel mid building of the Geest Keen Iron and Steelworks at Cardiff was pamted in 1956. using calcium plumbate paint at a pnmer. The surface was not pre-treated in any way other than degreasing with white spirit, and after priming it was pamted with one lead-based undercoat and one lead-based finishing coat. The paint system is subject !o quite severe conditions of exposure. There areindustnat fumes, deposits o* powdered l>me and iron onde. and furthermore the site is within a quarter of a mile from the sea. An eiamina'.ion in 1962, some six years after the original pa>nt<ng, confirmed that no flaking from the galvanized steel had occurred and at no time had it been necessary to renew the priming Fig. 1 shows a close-up view of th surface at this time. Case 7 A new budding, erecled in the Spring of I960 at the Abbe; Works ol Ihe Steel Company of Wales, has gal vanized steel cfadd<ng painted with two coals of calcium plumbate p'lmcr and one coat of an exterior quality bdumen based pamt. The surface was prepared simply by degeas<ng wdh white spirit. The site is only a short distance from fhe coast and there fore the exposure conditions are partially mar.ne as well as mdustcial. Fig 2 gives a view ot the plant. An tiaminalion of the condition of the paintwork in the summer of 19&. showed that after four years exposure H was tut m excellent condition, with no signs of any need f tor re-prim>ng. Fig. 3 gives a dose-up view of the surface at thu time. Case 3 The roof of a power house at Richard, Thomas and Boidnin's works at Scunthorpe was constructed of galva nizing sheeting in 1958 and pamted with a calcium plum bate pnmer and a top coat of white lead phenolic finish ing pamt. after degreasing with white spirit. The environ ment is a severe industrial one--a sulphurous atmosphere with depositions of finely powdered time, coke and iron f oxide dust. Examined late in 1961. alter over three years service, the paintwork was found to bo in very good con dition with excellent adhesion to the galvanized surface. Case 4 In 1961 the City of Montreal In Canada began to > replace its existing temp standards with a new design. These standards were fabricated from sheet steel, then hot ? dip galvanized and pamted immediately with a calcium plum- bate primer applied by spraying at the gatvanizer's works. They were then transported to sites and further painted with an undercoat and finishing coat after erection. In addition to the general town atmosphere to which the paintwork is exposed, the bases of the standards are subject to attack by salt used for snow clearance during the winter. The specification of galvanizing plus calcium plumbate priming was chosen to avoid the rapid deteriora tion of the base of the standards that was ptcriouilf experienced. In 1963, after Over Iwo years service, the paint work as a whole was reported to b in good condition, with no fj<lure of adhesion to the galvanized surface. ....v?-^*?**r?*iw,'iw-m gjigWTOyi^ . rr- O LIA23529 .' Lead in modern architecture .-*a I * of pmf of (ho C'ljr of lomJon vhQAn in iei*r * fo HwM*#fr the important iolc played by Tj vhevf in budding. lod.tjr 0 <n (he p4t The dome of S' Pau`. no* a boot ?S0 , cai % old with motl of (he original -id co.n-ng si.H intact. will be read*1* crcogni/cd. 1A Thr lorn r p >i of |fir pn furr < an be i w i (he impte**ne - a h*-jvJqoaMerk c*l The Trrei* nrMpipn jl Pr.n(.ng Hout> Square. ihe *(< Ih it lias t><` n the home of (he paper > n<. .1* foundat-on in t 7K5 When the photofl'^ph Jt 1aen. all the rebu-lding work h<J not reached the final tfage, but the mim new hu*ld<gi j i seen complete with tterr U-Ad-COered pdchrd rooU Hee, m contrail to the tt'OAg'r moulded *<h.H'Ctu`* of Ihe Si Pjvt'i dome, the roof hdl the mo'r vmplr And sharper hoes ot contemporary <Jr i,g-i, to *h.i h the use ol lead toer.rg , (Vjrt, adapt able Whilst kud *hf t not so m dr-ly used tor root f-.e* <*g today Jt in the pjt. >t it i! i-as no peer as an c? .aiding roof for Outstanding ba-i.Vjigv (t *iM g>,e a ' iong i.te wth t.ttV or no ecn in cr u ov* d pont on*. and Aid bu:fd pp\ bu tf tc ta>! the best v .- f to b the chi apest in the lorg r-n A , tt, 4i'j-y. the n-t f.g J --* V-. C.n a j , to *-e. a! a 7 i~C- te.- **io'e of A''o!ti | 0't.iet n-01} rn lead root. ; .i* i.` *** !o a i i t1'.! k cf it', j ''.. C * "f "* r fl'inp c* f.a-IJ igs standing on Thames VJ< South 6 ink in i <HU,rn Wabr-oe .-.r<! W* ?m.::!, L* dg*c * *> 4 *. g*-: o' 3$' M ft * to 'd-ng tj . pr, t l t:'r tho** * 'f a 'o St Pj u 1'* .ir-J !* oc* ,s . tj n', in a .c , "01. r { .'i f on V/ ?V . o'f' 4 o' It t CO tt :h- run! : . t % rn ;*o u > *. * <i` -.-ut 9 a -u I 73 . er-d a th a !1 * * f-AS 13 UMiH','- I, I'.M A3';'*.s.ti,"r,\ A? A >&! A . VI ?ch.;. Sdljll o' tf.-\ t , t ) J- -J '" 1. f.:.-Jc ;n. * 'ad StO'-c- *A -ng .. e-d a *h.n v'S`i| of A'-nl^.r of Lo*dyf* L.>l A' >!c* c fAnrtn'Ar** --Ml*- Tc*'*'. Anothe r sf'.kv.g - t ,' : '} tti.it j p :.*iethe ( C.nf'..Tj*0r4r| on of { *. `.i f T f.: <,PoiMriJ nt S' K At I * *- Oo< k - ** * ( J i 'C * ! : a hi .Jii j vV* . 'd d >.'>a ! oH t * 'or o', I r fore*- of Ihr Po't C* Lonrjm AutfiC'-t* It ** l*| * iC*1:* Ml i *^n-{ > of t*} .*' .-**<!*> iniSoSU'il f* u*i Af'rt I'.lt b< i n *f * gr. if i.ontorm Lc'h in , . a * -J ii'l-jj* He A-M. I'li- a j '(*i)o *c in i |*nr c.dr i o* A'i f' *i <K A'i -Ji. a P- nfon A Associ-tf* * (*a c - V.P'.mJ^i * e. liu t.S>:.{} of sf\ ngih inj d gn.f) *<th a 1 o>- cf t<AritA*`.1'iny a mi! '.fo,')f ni ! ma I* in T*.e tr.uJ* 1 o' V;r f. ry din t t.o.M nys ' i*"pO'ta':t u'.r of ii id sh* H nn thi* buiiil.ng tv a * '. inj` :l.ttl r 'g l-i Mu- f* -<di nt*.' Ap.irf*r nlthAt i* i- ;'-.a*"f on flu- p..i:fi flnf fyo* fig 1 (<>019 general r a o` !*> .ipaflnu-i.f a iid v twins the crcpi of the i'-.wf *orh ie img tor f.isriK. i !-* f.inV toutr As can be n t'om Hie <los<- uj>. ( >g C li.- Ir-adeOik lias Ctren, ; `i-*r; fmet. to which thr v* t * -M m !!-d joints add v Nu a I ' *r t-c.td shwl. di*sp;f< ?IS c <<-lyi.uwfi.i If^ 1oa m-(firiu i v. -igfh, can bn Applied to near .eihrjl or .i-H-c a I ' u i fully -..j'. sf.rc lor.I>. (/ pro.it.<iq t.*ngs at Hu- light to gi.n pioper suppoif ^ iiT'piiftanl use of l-.ut ci thr St Katharine Dock A j i lo< ri.imp i*roof <cii" rs inco'roiali d min 'ir Ml . ,:ii i, ..* !M, .g% I The ** ( tuoil* Mi d P'l '1st c or< pov-d au<i"`'j,i:i y . nq . da t i.(h :: (r uii:0Uii ?;*! r V . fi etw>t 1 f-i J'ir*{s!! !lJs! S'< iiHj, el!!'f ! fo !5 . e *. tn1 TCTT V ,U XV*r"jrnr"r- **<3*1*1*I* * / UIA23530 j '. .V alrY - S.SriaNra* ' VifcV 1CJl.'.i'-^-^:t^ d*fbp-inoof y ct y;r? 3*rt *"*,,*w:COU\* 4lb. | ^ d f ! f J ddzld dddddddddd d d d ~ WW*WH*,WHWWTO^ id Jj tj [i j eThI el H id ^ ^ ^d ^dddddd.d 1 ' df'r<< tf aj I ^ j;f- 'N *:r ! f^-CM 4KS i * *-- } Kl* < o t-'CJCJl, i-rr _!' lu I'*** : : } v.ss *. ^ : r.iA.trl*f\ &* *-; M C-' \i V '..*.* ' (} T'la*. 1 ,. M\ L '.own !K < i! mci''s .-.i!-b<t. c <1*, t- r-" ;ii"l.r fl-r|% t)r -g ,o'^`-r<l A-!*- . *c *) . a (m a > i ! . *(4< jo-'!* fc.-.a^j ,-t*-vyrfd r j!*>- <! , g*i<i>-i-% i.K ofj'O'a! ftg a f-t :. . v* .s f'g ^ aO-J',or\ to <'*,'* a a mIIik I.j j M a i1!, II i hC' - 3 nlv t-4 A \!'.;; c*' J<1 Um vt(< 1b %q *1 Ai.UlAliJ , 4'IXJ ir. *n n 1o- 1pufprW o! r. t*ia! ,(r, ,'f cc`l, < !*- J ,r l*-r , M.< *1 jontS i\ i*-d ow!*'d* . r^c,' if .c'. .* f g 2 undoubted1** 3o'^fs < <ii4nl*gft o-f r.^Vna1* *u<1t damp poo< COjikn. uncf A ' > a fftyh 4-h ! nip-ib' jb'o ot high ' i -. *bt h is ayl^ sh^pt d 4n*l wU & <! f <'< <* i'oi!.oi to 'ni/if a <lo*t- ( ( nd c <c a load r fEV*&T ' 4n^nAi^'^r i.'TT \' "' V LIA23531 ..w.. .^J.-.-~.-'-i--i-uf^ wr*.if.v, r.w'w'n,,h>.>jiJi^.'i i .wS'w/; Lead/asbestos anti-vibration pads i j ':, ;i ;-i "Ti } ;q f i } -! Fl { -.- -1 -M For many years p^di composing lead shed and com pacted fibrous material hi.f been successfully used at anii-ibration mount.r.gs, both in Europe and the USA. The pads are made m vanous forms, but they consist basically of layers of lead sheet and layers of asbestos or wood fibre board Shown above is a Cut section of a trp.c*f pad developed in the US A tHthicknessulJin andtheouler layer of lead sheet. about i w. thick, encloses two layers of asbestos board separated by a steel sheet stiffener, h seems that such pads were fust used m budding nearly SO years ago ahm. on the recommendation of the New York Central Railroad, they were instated to isolate build ings on Park Avenue from the vibrations caused by the passage of trams on the adorning railway S*nce (hen the use of the pads has become an accep'ed method ol re ducing the 1ransm.-ss*on of vibrations from rad and road traffic mto bu'ldmgs. and among important bu*ld.ngs recently isolated n th.s .*, are the new Ue.o Carb.de and Pan-Am bu.'d.ngs, both m New Yorh. Atirr thru intioductmn for sVuctutal iso't on m bu>ld-ogs. the pads were subsequent-, applied in t**- USA as meunt* mgs for heavy machinery. a *e!l-Snow' nampte bring the rvr wvpaper press*** I the hr* YerS Hr`d Tr-bune The t uropean use ol the pads eas m tael. \.e.* qu.te re<* ntty. been confined to the erg.nrermg industry Machines mounted on the pads (us-i'r the lead fbreboard t,pe| are qj.te common . Francr and the UK. where they ha.e been wideiy used under flic; 'immmi-i `o'gct and a'so under rr.jch.nv r, t*>t pa** Cu<arly sens : <e to v.brat-on 7he efficacy of *ra3 ashes*!- pads has _s tieen der-.pnS*rt,1 Over the last 50 yea's >n 4 w>de range O* prjct-cat arp''cat`Oe.s On` m re-cert years. hc*rer. has th-f been a Systematic attempt t- measure t*>- character.st.es of the pads unde* ,j*,.eg leads and or a wide ra-'ge of frequencies Th.s wo*k is e ng earned Out by the Irtr-rnational lead Zmc Re".ea*c* Organisafon. Sp*C>al f-tfd tests hae been earned Out *n conjunction *.th the tabo'ator m^est^atron. and in addition the performance of pads in several weft Snow- applicat-oni has been c'osefy studied and. where poss<to>. mea*ur-meMs of the degree Of isolation achM-iv-d have been made ft has been shown that, as the bearing lead iS increased from ?00 p s i. to about 1.000 p s . the pedormance cl the pads it improved and te*-, become e*cche at tower frequencies. At present the theory of Th- behaviour of the pads -s still not luf'y uodr's'ood. but t*e stage has been reached where operating conditions can be reasonably well defined --particularly <r. bunding applications It is interesting to note that isolaf<on values predicted from theoretical considerations have invanah'y proved to be lower lhan those actually achieved m practice. Results for two particular budding msta'iabons are Oescnb.-d br io*. The Philharmonic HaH m th* new Lincoln Centre for the Performing Arts in New Yc'k >t bu<!1 o.rr a subway rail road. and lead asbestos pads were installed under the building columns to isolate ! from the v (nations caused by the traffic. Stacks of pads making a total thickness of 3 my were placed under the columns nea'x-vt to the railway but the thickness was reduced for columns further away From a wide range of measurements earned out on site the consultants concerned have assigned a value of 10-15 d8 for the low frequency v.hral.on reduction. Smce low frequency vbrjt on is m (act most l.sety to cause annoyance, this is a .<-'y va' victory result and a marked improvement on the estimate ol pad performance that would have been made from the early research results. The second application concerns the Quern tl'/abelh Hole! in I* yntre.ll The hotel luild-ng is .mn*ed..ilely adja cent to the Dorchester Boulevard Bridge, both structures being located directly above a large array of tracks of (ha Central Station of Canadian National Railways. Smct the columns of fhe hotel are isolated and those of the bridge are not, the situation s very suitable for a direct comparison between an isolated and unisolaled structure. Measurements were taken simultaneously at the tame levels m columns side by side, when trams wwca trevethng on the tracks at distances from the eolumns of 17 to 220 ft. Based on these measurements the consultants calculated that an average reduction of 8 d8 had been achieved Ovee the tow frequency range (20-300 c p.t.) of vibration--again a better result than was epected. More accurate prediction of pad behaviours should ultimately be possible. In Europe, developments have taken place along somewhat Ciherent lines, because the use of the pads has until recently been confined to machinery mountings. Tha 1*-ud wood fibre board pad has been the type used for this purpose, either to isolate the machine from general vibrat.on. of to prevent vibration from the machine being trantm. Jtcd through the shop floor to other equipment. Mr at u'v-mentl made m IMS at the Geneva School < Ho'otogy indicated that the pads behaved as 'elastic* matey,a!* under loads be tween 1$ p s.i and 215 p.s.t. Based on thu f.ndmg. nearly all pad installations have been dei-gncd to ensure that the total of stahe plus dynamic lo.id ng does net eiceed 200 p t r To isolate forges, this *ivn means that the pad ar*-a is calculated on a stat< loao ng of less than ?Qp.si. giving a capacity of up to tftOpsi for the cl.na-nic loading wthout nceedirg the 'jvtic l.rmt'. Obviously, such a h.gh dynam.< loading is possible with a fo'ge. but there are many machine appliCJt ons where th* dinm-c load-ng iS unUely to be SO much in cictss of the static toad. In sp-te of this, the limiting of static loading to such tow hQures has become virtually standard practice in the UK lor machine mountings. (n 1002 a series of tests was earned Out by the title institute of Fluid Mechanics on the effectiveness of pad isolation und*>( Ihr concrete foundation block of a grinding machine. In these tests, pads t <n thick were installed over a suffi ciently large area to reduce the static loading to 14-2 p s.i. Measurements of vibration amplitude were taken in three directions, at right angles on the concrete block, and in the same d.rechons nearby on the shop flooh Transmission factors of 0*06}. 0-17 and ^*14 were obtained which can be expressed approximately as ttoUltons of 24, IS and 17 dB. Other measurements carried Oul under varying conditions en-phawed the vital importance of ensuring that there it no post'bility of bridging or short circuiting which can minimize the value of the pads. Tests on other machine tools planned in the UK wilt, it is hoped, yield further reliable design data. Taken together the American and European tost results indicate that effective isolation can be achieved at 'high* or 'tow* loads; the relatively poor performance obtained at intermediate loads being assooateJ with the natural frequency of the pads. Uo loads are not practicable, however, as far as budding applications are concerned, and in the Montreal application detenbrd, for e*ample, specially dusigned column bases were required to Veep the loading down to the 900 p.s.i. range. For budding applications of the pads m the UK, the Ameri can practice of using the high loadings is being followed. Eamples are, the rebuilding work at Sloane Square Station, London, and at Nr w Street Station in Birmingham, which are perhaps the fori-iunners of a more extensive future use of the pads for Hus purpose n the UK. j; !* 1 ; >