MAIN ROADS. Issued Quarterly by and with the Authority of the Commissioner for Main Roads.

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VoZ. XVII, No. 4. Sydney, June, 1952. Price : One Shilling - ___

CONTENTS. PAGE.

Traffic Aids on the Sydney Harbour Bridge ... ... ... ... ... ... ... ... ...

Specifications for Road Gravels and Sand Clays-New South Wales and United States requirements compared ... ... ... ... ... ... ... ... ... ... ...

Indian Road Engineers visit New South Wales ... ... ... ... ...

George’s River Bridge becomes Toll Free ... ... ... ... ... ...

Central Tree Planting by Councils on Main Roads passing through Country Towns

Road-mixing Process-Trial length near Maroota ... ... ... ... ...

Steelwork from Germany for Swansea Bridge, Lake Macquarie ... ... ...

Organisation of Plant Maintenance and Repair ... ... ... ... ...

Military Engineer Units of the Supplementary Reserve ... ... ... ...

Payments from the Road Funds for period 1st July, 1951, to 31st March, 1952

Main Roads Exhibit-Construction Industries Fair ... ... ... ... ...

Tenders Accepted ...

Sydney Harbour Bridge Account ...

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Additional copies of thio journal obtainable from the- Department of Main Roads,

309 Castlereagh Street, Sydney, New South Wales, Australia.

Annual Subscription, 4/- ; Post Free. BOX 3903 G.P.O. Telephone : M 6231. Telegrams : cc Mainroads ” Sydney.

Reprints of any portion of this publication, unless specially indicated to the contrary, may be made provided the exact reference thereto is quoted.

Cover Page. City bound traflc on Sydney Harbour Bridge during morning peak period.

[Photo by Frank Hurley.

Next Iswe : September, 1952.

97

Trafltic Aids on the Svdnev U J Harbour Bridge I . llicrc Ixts Ireen ;i irqiid increase in trattic over tlic

Sytlne). I 1;irlJour Hritlgc sincc tlic \ w r years. tlic xverage 24-liiiur volume. of traflic iiow 1)eing approxi- iiiately +o.oc:o vcliiclcs. 111 the maxiniuni peak lioui- siriiie ,.Ciao Yeliicles cross the bridge. The growth of traffic is sliowi 11). the tliagram un page 9s. The bridge is now heavily ch;~rgctl at peali ppriods antl can function tn its fri l l capacity oiily ii tlie tlrw of traffic oii to ani1 ;icross it is orderly antl free of interference.

I his article rlcscrilwh tlic iii~‘aiib which have been iic\dopetl to proniote s:tfet! of the Iienvy trattic Hows. :tiid to e n d ~ l c tlic fu l l c;tpacity r r f the Iiritlge t ~ i I)c :tchicve(l at 1 i d I)eriotls.

’I’lle tcrtal length of the roatlwny over tlie britlgc and ;~pproaclics. 1mxc.n as tlic Hradticlrl Highway, is 7,550 feet. On the bridge itself and on the northern approach, tlie roatlway is 57 ft. 6in. wide, and is divided into six lanes. The nc\v toll Iiarrier. with tlvelve vehicular openings. is situated in 3 1)nh on the sollthern approach. That part of this aplmacli on the city side of the toll harrier is sn%cientl\~ wide to vrovitle for seven traffic

I .

The Bridge Roadway.-.\t a l l times spcetl is restricted to 30 miles per liour. I’xcept at peal; periods. tlirw lanes across the Iiriclge arc used for north-liucind traffic niitl three lanes for south-liountl traffic. Originally there \vas a donl)le. or “no crossing”. continuous ellon on^ traffic stripe along the centre. and the other lane linrc ( or stripes) were continnous single yellmv. The traffic i n tlie t w o tlirectiriiis is Ilrarketlly unbalancetl at peak hours. antl the present practice is to m e four soutli- hountl ( o r inwards lancs in tlic mornin:: peak, and four iiiirth-hounil iiir trritn;trtlsi lanes i n the evening peak.

I n ordrr t o secure stit.ty ant1 iiiitxitiiuiii service froin 4 / z and ~ / 4 laiir wurkiii:: in peak periotls. the following arrangements apply :--

I . The original ~louhle yellow coiitinnnns stripe has been replaced Ly a continuous red stripe nine inches \vide over the Iiritlge strnctiire and imnietliatc approaches. .i police tratfic regulation has heen made which requires that the red centre line shall not bc crossed at

Iwes and is so di&letl. 13e;ond the Iiarrier to the any time Iiut permits a vehicle to be driven. Ixitlge structure tlie lanes reduce from twelve to six. during the specified peak period, iti the first (The Iiarrier was built in 1940 to replace the oriqinal lane to thc right of the red line, provided six-ni)eniny struetiire. as tlescribed in “Main Roads” that lane is entered before the coinmencement for I>eccmber. 1949). of the red line is reached. Thus, there is

*87.%RR-1

MAIN ROADS. Vol. XVII, No. 4. ~ ~~~

One of the s i p s sus- pended over the road- way during peak

period.

June, 1952. MAIN ROADS. 99 - - -. _ _ _ ~ ~

Old lay-out at City end of aouthcm approach.

susyciitled froin the portal frames of the main arch span of the bridge. 111 off-peak perioils thebe signs are drawn up I)>- hantl \\inch out oi sight of traffic.

The inarkers nsetl 011 the rtratlway doiig the line separating tlie opposing trattic streams are niatle I I I strip ru1)I)er. 1i:iIf an iiicli thick and six-i~~clies wide. supported 011 a base made ii-om rulilrer conveyor belting. They are not ea+ tlisplacetl 1vhe11 struck by :I vehicle and 1 1 0 tlatnage is tlonc either to veliicle or inarker. The vertical ilrilis nierely fold ovcr and rectril. 'l'he letter- ing oil the niarlters is I)lacl< on an aluiiiiuiuin paint hack- groutid. wliicli has lreeii found to give reasonable visi1)ility mitler i v i ( l e l ~ ~ vai-yiti: conditions of light.

I<xperiinen~s have been carried out over a11 extended period to devise soiiie nieaiis of making the niarkers iiiore visil)le at night. \-arious types of rigid reflectors were tried. but their life \vas generally not more than two or three clays. Re tk r results ha\-e lieen obtained

d ClT"

New lay-out.

with the use [ i f reflecting fabric, but this inaterial is not yet in regiilar supl)ly. Tests h a w also been made with glass 1)eads. Slioultl it Ije practicable to arrange supplies irf a satisfactory reflecting material, considera- tion will be giwii I O the m e c)f yellow paint 011 tlie inarlters. as this \ m l l t i tilalie them mmewliat more conspicuous in daylight.

The placing and atljustment of tlic marliers is carried out by three rniployees who are 011 duty on the bridge tluritig the iiicirning ant1 evening peak periods. 7r\vo of the iiieii fot-m the crew uf a tcnriii: truck for removal of stalled vehicles. The third inan usually retnains nrar the toll Inrrier niitl adjusts markers in that vicinity when the iiiiiiiI)ei- of toll openings is varied. The towing truck drxws a trailer from which the markers used to separatc oppo5iiig ti-attic streanis iii tlie evening are drt~ppetl, as the vehicle proceecls \vithout stopping, on to spots tnarkctl (III the tratfic stripe at roo-foot intervals. At the end of the evening peak period the markers are picked u p with a hook and depositetl in

Islands, lighting and I' pavement marking , southern approach.

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I00 __ MAIN ROADS. -- -

Vol. XVII. No. 4.

Movable Rubber Traffic Markers on routhern approach during mid-afternoon.

tlic trailci- (inc ci i tlic iiicii. ’1‘li< triick : i i i i \ . ch uiitlcr l’olice nintor cycle escort \ i - I i i l ~ ~ placing : n d recoverin:. h e niarkers.

Other uses of Roadway Markerr.-l<ulilm ~ ~ a v c n i c n t markers ;ire also used to guide trrrHic at other locations 011 the I)ritlge ; for exaiiiplc. t o divide tlie ( i p p ~ i s i n ~ streanis cif traltic nii licit11 sides of the toll harrier. .\t tlie morning peak perioil. nine openings ;ire user1 for city-bound traffic. ancl three openings for out-liotintl traflic. At the evening peak pcriod tI1i.i allocation is rebersetl. Hetween peak periotls, the nnnibrr of toll barrier openings is varied tu snit the trallic flow. The markers are moved from time to time hetween 7.30 a.m. and 6.30 p.m. to corresponrl \\.it11 the openings i n use.

Six rubber markers at 5o-iert intervals are per- manently pegged down at each ~ n ( l cif the red centre line to serve as a remintler that crcissing of this line is prohiliitetl.

Traffic Islands at Southern Approach.-,\t the pcitit where several city streets join with the approach roadway to tlie Iiritlgc. there was originally a central traflic island of approsiniately rJ-feet dianieter. \\‘it11 the growth of tratfic. this was iouiid t ~ i Iic insufiicient to piiitle traftic satisfactorily cluring the evening peal< period, principally 1)ec:itise the streani cif tratiic froin (;rosvenor Street ( see plan \ <lid n(lt join s1111i~~t l11~ with the stream of traKic coniiiic i r m (‘larelice Street. ()rtlerly faster How to tlie Iiritlge h:is n ~ i w I~een hecuretl by prolonging tlie eastern kerb oi Clarence Street. as shown on plan. antl Iiy providing two c~increte lierlietl islands. In addition. ri11)Iier paveiiiciit m;irl,crs have beeti pernianeiitly peggerl tlo\vn s o its to aid in getting the Clarence Street antl (kosvenor Street streams r n n n i n ~ parallel on to the bridge approach roadway. These markers form. iii effect. ii narrow chrrnnelising island.

Thus, the tr:ilfic froin Kent. Clarence antl < h s v e n o r Streets enters the bridge roadway sniootlily and ivitliout merging ; any weaving can nccnr only after passing the

traiiic i..l:in(l\ :\m1 I)dllrt. reaclling the toll barrier, a distance ;IlKJnt feet. or immetli;itely after passing the toll harrier.

It \vi11 l)e noted that the 1;tyciur oi die islantls is such as to guide anrl ~narslial trallic coming off tlw bridge antl \visliing to inalie a right-hantl turn t o Kent Street. 1 his traliic crosses tlie line of Grosvenor Street at :t rialit angle and at a detinitc. location. \\:bile this has added to safety. it has also hat1 tlie effect o f encouraging iiiore traffic at the morning peak h(rrir to cnter the city via Kent Street, thereliy relieving congestion i n York antl Grosvenor Streets.

Towing Truck Service.-The 1)re:tktlnwn or stalling ~l vehicles on the bridge and imnietliate appruaches creates a serious interference with the smooth flow of traftic. In order to retlnce this. a free tow truck service ha. heen instittitetl during peak hour . l+.ull (letails of this were given in “Main I2oatls” or Septenilicr. 1951. Over the first nine months c i f operation. 230 disabled vehicles were removed from the In-itlgc Iiy the towing truck during peak hours.

Supervision.-The installation ; i i i t l olieration of traffic kicilities on the Sytliiey 1 larbonr I l d g e , as \vel1 as the ~naintrnance ( i f tlie structure itself, is carrictl (iut under tlie supervision of the Ikpartmcnt’s 3letropolit;in Iln- pincer. Mr. I.. \\., l-Ja\vley.

l‘he ’l.r&ic liriinch of the State Dep:lrtn~e~~t Oi I ’olicc.. mtler Sn~~erintendenr \\.. It. I.awrence, provides the 5taff for nianual control oi tlie intersections at each end of the Iiritlge alqiroaches aiitl also for the I~atrolling of tlic hridge antl approaches. I’ast solo nintor cycles ;ire used.

Siiicc the introtluction of I a n i I I g of the roatl\vay ant1 o i unequal lane usage i n the peak periods, the traffic flows have heen ol)serval)ly niiicli niore rirtlerly antl there have Iwen no fatalities or injuries due to head-on collision or opposing side-s\vipitig i n the niarginal lanes. It is notable. ton, that the use of reflector studs in the lane stripes has discouraged drivers from tlrivinz “on the line” so that relx~inting is less frequently required.

I .

Specifications for Road Gravels and Sand-clays New South Wales and United States Requirements Compared

0

1. OBJECTIVE. The objective iii this article is to descrihe tlie reqiiire-

ments in respect of properties aiid physical coinposition which a road gravel has to meet in order to give satis- factory service in a pavenient ; how these requirements as to composition are iii:asuretl or estiiiiated liy Iabora- tory tests ; and how specifications are framed to exclude as many ntisatisiactory materials and to inclutle as niaiiy satisfactory inaterials as practicable.

The compusition of gravels is so cumplex that coni- plete testing is not practicable. Testing procedure must be a comprimise between the greater rlsk of wrong c!ecisions if the number of tests conducted on each sample is reduced and the estra cust and difficnlty of testing if the number of tests is increased. There is no theoretical method by which the optimum amount of testing can lie tlcterniined. I t depends 011 tlie frequency with \vliich materials of different types are met with i n practice. I t will probably differ to some extent in tlif- fercnt countries. antl even in different p u t s of the same country. because ol the wide differences that occur in nature hetween the cotiiiiion soils in different areas.

The specifications of tlie American Association of State Highway Oficials and of the Department of Main Roads. New South \\;ales. are quoted and discussed in this article. The former may be taken as typical of general practice iii the United States of Rmerica. though a number of States adopt specifications that ai-e of a rather inore restrictive character aiitl/or difier in some respects. Similarly, the Department of M a i n Roads specificatitins are rather more restrictive in their effect than the .A.A.S.H 0. spccifications for certain materials of the less usual tvpes, and there are other minor differences. The differewes in both cases no doubt reflect the inevitable differences in the local materials available. as mentioned in the precedinq paraqraph. How tlie Department of Main Roads sneci- fications differ in their effect from the A.A.S.H.O. specifications is explained in Section ; of this article, which also describes the reatures of the New South \\’ales materials situation that made it nccessary to include in the Department’s specification provisions not considered iieeessarv hv the I\.A.S.H.O. for general application iii the United Ytates.

I t should he mentioned in this connection that the need for atlditional restrictions with certain unusual materials antl. therefore. in areas where such materials are found. was not overlooked bv tlie A.A.S.H.O. The last sentence of Clause ( I ) of that Association’s speci- fication, auoted helow. draws attention to the need of further limitations with materials of abnormal specific pravity. porosity, or grarlinq. Tt is onlv because of fairlv frequent cases mr t in New South Wales of materials with these particular ahnorrnalities that the additional restrictions ineluJcd in the I Iepartnient’s specifications IIRYC heeii found necessary.

2. USE AND PROPERTIES REQUIRED.

KUad gravels and sand-clays are used in niaiiy dif- ferent pavements. but all uses can lie yougnly grouped into tiirre main rlivisiiins :-

.\. Top conrses suppurtitig only a thin hituminous

I(. ‘urfacc courses without any further cover (the

C. Lower courses of pavements under thick upper

Ftir the first purpose, support of a thin bituminous surface, the real physical requirement for the material is that, 2s laid and compacted. i t sliould not deform uiitluly uncler any conditions of weather and traffic loading to \vhich it miiy he subjected. Tf this requirement is inet the road gravel or sand-clay course will not of itself cause an!- trtinble. If it is not met, the movements in the tnaterial will eventually result in cracking and disintegration of the bituminous wrface no matter how well that surface and the remainder cif the pavement is constructed. There is also the essential practical requirc- ment that the material should be capable of being coni- pactetl to the thickness of course required with a smooth firm eveii snrhcc suitable for the subsequent coiistruc- tion of the I~ituminous surfacing.

For tlie second purpose, top course of unsurfaced pavenient. the first important requirement is again the ahility to resist tlelormatioii under trafic loads. There is, Iiowrver, one important differenre in this regard as compared with the first case. While deformation must still be liiiiited. tlie permissible deformation is much greater than in the first case. A second requirement of equal iiiiportance is that the surface shall not wear or disintegrate rapidly under tlie action of traffic and weather. The third is that the matcrial should be cap- able of being compacted to a h i even surface and of being reshaped to a similar good surface after traffic wear.

For the third purpose, base course, the principal reqiiireiiirnt is the ability to resist deformation under traffic loads. There is here a very importailt difference as compared with the first two cases ; owing to the load distributing effect of the upper courses, the stress intensity is much lower in the base course than in the surface course. The material must be capable of being compacted to a suitable standard of surface. but a much higher dcgree of roughness of surface of the course is permissible in this case than i n the first two cases.

In each of these three cases it is extremely difficult to conduct tests that directly measure the actual properties desired. The usual approach is to study the composi- tion of the material aiid deduce the properties from its composition. [n practice. only materials of suitable compositioii are used or perniittecl and the specifications

wearing surface.

ordinary tinsurfacctl “gravel” road) .

courses of various kinds.

I02 ivlAIN ROADS. -

cover the composition rather than the resulting pro- perties. :\I1 such specifications are I)ased on esperi- ciice. I he range t i f suitable coinpo~itions has heeii determined by o1isrrv;itioii over niauy years oi tlie ser- vice givcii lry ~i:ivciiients of inany different conqxrsitioiis. lixpcrience has sliowii that to secure adequate stability. or resistance to tleforniation under I t n d , the road-gravel or siintl-clay intist lie "well-graded" from coarse sand size to clay. 'l'liat is to say, the material n i m t 11c cuiii- posed of all sized particles in that range i n sriital>le pro- portitins. 'The proportions ( i f the m:itcriali i i i tlic r l i f - iereiit size ranges are very important and the major ljortioii of Iirrtli tlic A.;\.S.H.( 1, an(l S w v Soiitli !Vales hpeciticatioiis i h tlevotetl to this feature [ I f tlie coiiil)osi- ticrn. 'Ihe grading. or the distribution of pirticlc size. inay be illiistratetl graphically by plottin:: the "grading ciirvc". where the proportinn snialler tliiiii a n y giveti size of sieve opening is plotted against thc size of sieve opening. lf suitalily graded. niost of the usual soil minerals form satisfactory pavetneiit niaterials. Iiut it i h

necessary to incliitle requirements limiting or excluding certain tititlesirable groups of mitierals. Kequirenients as a niaxiinum size and/or proportion Oi large stone5 are also necessary to cover the practical coiistructionnl and maintenancc rcqiiirements. l'lie \v:iy tlicsc require- ments are covered in the two speciticatirrns is set out in iiinre rlrtail hereinafter.

~.

3. DEPARTMENT OF MAIN ROADS, NEW SOUTH WALES, SPECIFICATIONS.

(The esperiment:il and research i v r ~ r l i rii i which thr 1)cpartment of Main Roads epccitic:itiirns are li:isc<I were tlescrihetl in articles oii the tl:.sigii of iioii-rifii<l liavcmcnts whicli :Lppearcd iii tlic jniic. 1947. :iii(I hl:ircli. ~ y & . numbers of "l\lain liciatla". Thc nxjrk was carried nut iintlcr tlic 1,ersoiial sumrvisioii of tlic I I e p i tiiient's Lfaterids and Research I5igineer. .\I I-.

A. 'I.. I3ritton). A. " G ~ ( J ~ V / " ( i ~ t d " s c i r d d t r ~ " to rrcl.ir'r siirfocr frcnt-

The requirements given are irir inaterial as fiii+y compacted it1 the pavement. Sainples from deposits. ctc.. niay require special treatinent prior to testing. Tlic material will he suitalilc if it cotiiplies ni th all the fol- lowing requirenients :-

(a) Total "T' ( 1iy grading rule ) not tn eicectl 5. ( 1 1 ) lTppcr Snliil 1.imit not to c i c c ~ ~ l 20.

( c ) Plastic Tntles not to rsceetl $. ( d ) ~1:ixiiiium Dry Compressicrn strength not t o

lie less than 400 l l~/sq. in. if i i or i i i a l 111-acticc of i~ini~iact i~in iiiider tt-aflic is to lie i o l l ~ i ~ ~ c t l or 250 lli./sq. in. if special ~ ) r< iv i s ion is iii:i(lc iiir watcriiig. rolling am1 iniiiirrlintc mrface treat- iiienr.

.\ limit is also norm all^- ~Icsiralilc i l lr "o\-ci-.iizc" ( i . ? , , lrinportioi~ rrt;iinctl ,5 in. sq. qievc) ; tlesir;il)lc limit is -5 ~ i e r cent. of whole.

1 J l P J t t .

Thc gratliii:: rule cciniliiita~ioii is as i d l c i ~ v b :-

TXsregartl :ill ni:itrri:il rrt:lincd i n siliiiirc' sieve

Vol. XVII, No. 4.

June, 1952. MAIN ROADS. I03 ~~ ~~ ~~ ____

4. AMERICAN ASSOCIATION OF STATE HIGHWAY OFFICIALS' SPECIFICATIONS.

(i\iiieric:iii i\ssuciatiuii oi 'talc I ligliwsy ( )!iiCi;ilh'

specilications relirutlucetl liy courtcsy oi the .\hsocintioii. from its pubh'ation, "Standard specificatiriiis f i r i - high way materials, m i l i~ictliocls of sampling atid testing." Part T . j .

STANDARD SPECIFICATIONS FOR MATERIALS FOR SOIL-AGGREGATE SUBBASE, BASE AND SUR- FACE COURSES.

A.A.S.H.O. DESIGNATION : M 14749. Scope.

I . Tliese specifications covcr tlic qualit!; ant1 gra(ling of sand-clay iiiixtures ; gravel. stone IJ I - slag screciiiiigs or sand ; crusher ruii coarse aggrqate consisting of gravel. crushed sttine or slag coin1,inetl sit11 sciil mortar or any cotiibinatioti of thew materi;ils for use in t!le constructiou of subbase, base and surface coiirse<. The rec~iiirements are intentled to crivcr uiily inaterials hav- ing ~iciriual or ;iver:i e specitic gravitl-, ;iI)s~i~-~iti~iii a i d gratlation cliaracteri ics. \\'here other niatcrials are to he used. n p l q ) r i liniits suitalile to their use niust be specified. Types.

2. I lie LiiIImviiig tIl>es of mixturcs are specitietl:~ , . ?'?'pc I.-Ilisturcs coiisisting of stme, gravel or

m:i l or cru.;lietl s;uitl antl fine tnitier:tl ing KO. zco sieve aiitl ciinfciriiiiiiR to

the rec~iiirc~niciits (if T;~lilc I iiir grailillg /\, 1: . C' o r 1).

7'ypc. f /.-AIixtures coiisistiiig o f natural or cruslietl satid nit11 fine mincral Izirticlcs iiassiillg S o . zoo sieve and with or without stone. gravel or sl;q and roiiforniinp to the rec~uiretneiits of '1':iI)lc I for gi-atling 13 iir F.

General Requirements for Types I and 11. 3. [ a ) Coarse ;iggregatc (retained OII X(J. I O yieve)

for m e in Types 1 atit1 TI sl~all consist of hard, rltiral)lc pxtirles or fragiiients [ i f stone. grnvcl or slag. >\laterids lliat lireak up \\-lien a1terii;itcly frozen antl thawrtl or wetted and dried ilia11 not I JT iisetl.

!rear. l,os .\itgelcs tcst. i i f not mire t l i :u~ 50. Nott.--..\ higher 0 1 . lower 1)crcciitag:r of \ve:ir m a y lit.

qiecitierl liy (lie eiigiiieer. tlqie1iilitig 1111oii tlie materials availdile for the wid< .

4. [ ; I ) Fine agqregatc (passing S r i . I O sieve) For use in -I'ylies I a i i t l I1 shall consist c i f iiatural i i r cru.h:tl san(1. aiirl fiiic iniiicl.:il Iiarticlcs p a < s i ~ i ~ the Ntl. 200 hie\-c.

( 1 1 ) The fi-actioii passiiig the S(i. LOU sieve shall not I W greater than t\vo-thirtls of the frnctioti passing tlie KO. 40 sieve. Tlie fraction pssiiig So. .to sieve shall have a liquid limit not greater tlizm E.; and a plasticity itides not greater tlian 6.

5 . The cotnposite soil-aggregate ~naterial of Types I ant1 TI shnll lie free ~ ~ ~ J I I I vrget:hle mi t tc r a1111 Itiiiips 01-

I 1 ) ) C'(J;l1.5C ;lfiglYgZlt<' S11;111 h:i \ -C ;L ~l ( ' l~~~ ' l l t : l g~ (If

I d i s of clay and sIia11 coniorm to the grading require- ments of Table T .

Subbase. 6. Soil-aggregate materials for subbase shall cotiforni

to tlie requirements of Sections 3. 4 :ind j. Type I, gratl- itig iI> 13. C or 1). or Type IT. grading E iir F. The type and grading ilesirrtl shall be designated.

Nofc--\\'het-c local experience has shown that lower Iiei-centages Imssiiig No . 200 sieve than required in

try for subbase ~naterials iii order to Irevent tlaiii;ig:c. liy frost ;tcticiii. tlic engiiirer should specify such lower lxrceiit:iges.

Base Course. 7. Soil-aggxgatc inatel-ids Tor Imse course sliall coli-

form to thc requireiiieiits of Sections 3. 4 atid 5 ior Type 1. grxliiig . \ , I \ . C O I - 1). or Type 11. grading 1; or F. Tlic tylw aiitl g:I-atling desired shall be tlesigiiatetl.

Nofc.--\\liere local erlmieilce has shown that lower percentages passing No. ?on sieve tlian required in Tahle I arc necessary for Ii:ise course illaterials i n order to prevent dmi:ige by frost action. the engineer should specify such lower percentages.

Surface Course. S. SoiI-:iggregatc iii:iti~ials i i ~ i - surface course s l d

confni-in to reqiiireiiients for Type I, grading C or I ) . or Type TI. gratliiig 17 or F. l h e type antl grading h l l lie tlcsigiiated.

A'ofr.--\Tlicre i t is pl:innetl that the soil aggregate \ d a c e cinirsc is to lie maiiitainetl for sevrral years \vithout liitiiiiiiiiiius sui-face trratiiietit or other s i i l r r - iinpuseil inipcrvicius srirfaciiig, the cn~ i t i cc r slioultl specify ;I ~i~iniiniim iil S Iier cent. ~i ; is ing No. 2u0 sieve i n lieu of the mitiimutii perrentages shown iii Taljle I for grulinF C-. 1) or 77. and shoultl specify a ~iiasii i ir i i i i liqiiid limit (if 3,; :inti Iilasticity intles range of 4 to 11 i n lieu of tlic limits givrm in Scctiun 4 ( I ) ) . Moisture Content.

:I. All iii:iterials shall contain ~noistrirc sufficient to iiisurr that the tlrsign density requireiiieiits are o l h n e d when iiiatei-ial.~ arc CI mipactetl.

Admixture. IO. C;ilciuin cliloritle rised for the control ol moisture

shall meet tlie rcquirenieiits [ i f Stanrlartl Specifications for Calciuiii C'lili ii-iile i:\..\.S.H.O. I>esigtiatinn :

Methods of Sampling and Testing. I I . Sanipling antl testing sh,

the followin$ staiitlartl inethotl ciatioil of State FligIi\va!; Offic

i r 144).

accordance with l\meriraii Asso-

S:iiiililing . . . . . . T 2

ins and S:iliililiiiq Soils T 46 '1. $-

Tiquid Tiiiit . . . . . . T i ; l'lastic Idtiiit . . . . . . T Pl;isticit>- Tntles . . . . T 01 T'ci-crnt:igc of l\Te:ir . . . . T 96

Sieve .\iiaIysi< . . . . . . 1' I T :iiltl T 27

for Iiiqliwar Sd~gi-xlcs . . Prel)ariiig Saiiilllcs . . . .

104

TABLE I - G R A D I N G REPUIREMENTS FOR S O I L - A G G R E G A l R M A T E R I A L S .

l’crccntagc by weight, passing square mesh sieves. Sieve

1 Grading Grading Grarlitii. 1 ) I I‘ I v

- I I 1 1 I I

MAIN ROADS. ~ ~~

Vol. XVII, No. 4.

>-inch 100 1-incn _ ._ !-inch 30 65 No. I O 15-qo

5. COMPARISON OF SPECIFICATIONS.

:\t first sight thc 1)epartnicnt t i l A1:iin lir~ads, S e w South Wales, and ;\.ALS,H.C). specifications are widely dissimilar, Init in actual IISC they have iiiucli the same effect. The majority of the materials that would be pro- posecl for the uses envisaged \voultl either pass hotli specitications or fail to meet both. Cases where a material would pass hy one antl not by the other are nct very cotiinion. There are, however. certain iln- portnnt tlifiercnces. the nature of wliicli can only be untlerstwtl Iiy tletailrtl exaniination of the twrr speci- tications. This will he continetl to the important atid most critical case oi a top cinirse riiatl gravel or sand- cl;iy supporting a thin Iiituniinous surfacc. i.e.. thc. inaterials cnvisagerl i n Clause ; of the A..\.S.H.O. spccific:ition ant1 “;\” of the 1)rpartnient of Main Koatls. New South \\.ales spccificatioti. ;ilready qnotetl.

I n this cxbe the range of satisfactory coinpositions is iiarrmv, i f adeqnatr resistance to tleforni;itiii.i is to Irc secured. as if excessive deformation occnrs c11s age \vi11 result. eveii if tlie tleinrture froin a sat composition is small. Tn the case of an unsurfaced Invenient, the penalty for a sm;ill tlcparturc from tlir it1e:il coml)osition is relatively small. while in ii Iiase coiirse. with its lower strength requirrnients. a niucli wider range of coin~ii~siitions is satisfactiiry.

Tlie LA.zLS.H.O. specifications I)rovi:le six liossiiblc. grading?;. applicalilr h t h to natural illaterials and to prepared niixtures. The pradings applicable to materials which are to receive a bituniinons surface arc. drawn to lo~arithniic scale. vertically antl horizontally. in fiys. I to 6. I n .\irstralia. Kritish staiitlard sieves arc. used. \\:liereas i n tlie United States. .2inerican stantlards zre iiserl. Rotli sicve sizes 1i;ivr therefore lieen sliowii on the diagrams.

Tlie six different gratlings soecitied by tlic :\.A.S.H.O. constitute a familv. Each is of similar form. hut the maximuin sizr of agyregate atid the pro- portioiis of the laryer sizes decrease reeularly from typc‘ X to tvne F. Tvnes X antl B. with the largest agere- pate, are intended only for base coiirses. The other foilr. with a m:txininm size of I inch or less. are suit- able for either hase or surface courses. New Sotitli \\’ales practice corrcslmnds closely ill this rcspect : ty!m

A and 13 \vould he regarded here as very coarse road gravels with too much large stone to be suitable for sur- face course ; types C and 11 as normal coarse to medium gravels; and types E and I; as fine gravels antl sand- clays.

The .\..l,S.H .O. specitications are expressed in tlir siinplest possible way. The principal requirement is that the grading curve of the material should fall entirely within one of the bands of figures I to 6. Experience in New South Wales has sliotvn that this type of specification, and the A..\.S.H.( 1. liinits quoted. are satisfactory for what might he described as “uni- formly” or “regularly” graded matrrials. i.e., those it1 which the grading curve is smooth antl of the same general slope. I t is. however. pissilble tu draw inany crading curves ot’ very irregular shape withiii the limits c i f tlie .\..\.S.H.O. grading baiids. Satural gravels that have such irregular or uneven gratlinxs are iouiid fairly frequently in New ,South \\‘ales. antl many of then) have becn iotmtl to be unsatisfactory though they cocnply with the A..L\.S.H.O. requirenients.

, I I ART.E ~-E: .x .~PLEs OF NEW SOCTII \V.~LFS MATEI:IAI.S ~~

I ?,latt,rial l < c f c r u i w

‘l‘rst.

50 700 ‘ N o t il’,j” I , 5 0 0 r j o IKlOllC,

I.:xainplea. sI1owtl i n Table z ancl figures 7 and S are

;1fo/crii1f ( t i ,I .-:I typical “ironstuiie” ( ix . . late- ritic‘) gravel f o r m d hy concretionary tleposi- tion in a fine 3aiid-clay soil. This type of inaterial is coniiiion in tlie New South \Vales coastal lrelt t’rnm Gosford to Milton. Its i i n i n tlefect is the almost coinpletc a1)sence of the coarsc satid fraction. Many 1)ituinen srirfacctl gravel Ixivenlents coiistrclcteil ivitli this type of iiiaterial have failed. It coinplies. hrnvever. with the AA.S.H.0, specifications for type F. material in all respects.

.\ typical oversandet1 t1econil)osccl Tranite wch as is found i n many areas of New South \Vales. These materials ohviouslv lack cohesion and. i f not rejected nn siylit. would he abandoned after tlir first attempt at use. Tlioql i they cannot I)e cominctrtl into a paveiiient cnu rse tl lev iwinply wi rl l .~\ ..\ . S . 1-1 .O. specificatiiiii for type R tii;itcrial i n all tcy’ects.

as fclllo\vs :-

dltrti.r.iirl [ h j

June, 1952. MAIN ROADS. - ~- ~

I 05

.% FE.2. TYPE 43.

FIG6 TYPE F FK; 5 TYPE E

FIGS. I TO 6 A.A.SH.0. GRADING SPECIFICATIONS. Both these n1ateri:rls have irregular grading curves wise coinply with the grading 1-equireiiicnts. ‘l’his

over the cc~arsc satid s i x . the fault lieiitg in opposite requireiiient is supported by Kew South \\ales esperi- iiirectioiis in tlir two cases. Other similar examples ence. .4 local exaniple. slimvii i n Talde 2 antl figure could he quoted of irregdai- grading in other size 9 is:- I-;ingcs. Stiiiie tlificulties of tliis natnre iirust h a w I)een .lltrtrriol ( c ) .-.\rtificial !iiix of stream gi-”vel antl niet in the United States. for. in addition tu the principal saiid, frtrni hank it1 river, with Iiinding soil oi grading req~iircnients. tlic .-\..i.S.I 1 .O. sliecificatioue a h 1 uiisuit;ibIe gratlinfi. Vsetl for pavement antl require that the fraction passing S o . 200 C . S . sieve i d e t l in service. This material complies with should tint csceerl (\vo-tIiirds nf that passing No. 40 :\.A.S.H.O. gr;idiiiL: rcq~iiretiiciits except that U.S. sieve. This imposes a limitation of the slope the ratio of quantity passing the 200 sieve to of the gratlinr: curve in this size-region. and excludes 11g tlic 40 sieve exceeds the per- ccrtaiti irregnlarl!; graded tilaterials that \vould other-

*875RR--?

MAIN ROADS. Vol. XVII, No. 4. ~ ~

FIG 7. MATERIAL ( L A A M D . T Y P E E.--- U

FIG. e. MATERIAL (E)-AA.SHD. TYPE E---

M A T E R l A L ( C I 4A.SH.Q TYPE E--- MATERIAL ( D ' ~ ~ A S H O TYPE E--- -HD MAX. 200/40 RATK) LIMIT-----

FIGS. 7 TO I2 ABNORMAL MATERIALS AND A.ASH.0. GRADING LIMITS

June. 1952. MAIN ROADS. IO7 -I___ ~ __-. - - -

h \ : n to a very much smaller sizc. sizes i n the sieving range. what is required is :-

. is for the coarser

( a ) The geticral trend of the grading curve shoulrl lie Iier\veen certain limits.

(I , ) It shciulrl approximate to a regular curve. The detailed examinati~rii of tlie gratling curve Iielrnz.

the KO. zoo sievr is only practicalile Iby relatively t c d i ~ ~ u s i i i i d costly setlinient~ition methotls. Tlie time antl cost of testing is iiicrcased rapidly as the niiniinuni size deter- minec~ is tlecreLse:l. In practical work it is therefore necessary to closc tlic sizc tleteriiiination at some size that represents a reasonable compromise hetween the risk of passing somc uiisuital~le niaterials with inisatis- factory gradings and the high cost ci f testing all materials to a tiner hizc. .As a sulihtitiite for finer sizing niost specifications require some tests on the Iiulk material. Liquid and/m- plastic limits. shrinkage properties. strength tests. etc.. have been used for this purpose. They ai-e a11 closely correlated with average size of particle. antl thus witli the general trend of the grading curve. although they are incapable of detecting antl niea- suriiig irregularities in the grading curve.

Whether it ih rcasonahly sale or not to curtail the size deterniimtioii. and if so at what size it can Ire curtailed. arc q~iestions \vhich c m only be ;uis\veretl l ~ y experi- ence. Neither can be answered with certainty by theoretical reasoning:.. though the foIlo\ving argument suggests thr:t such curtailnient inay be practicable aiitl indicates the possible location of the bountlary in a general way.

The most CCI111111011 cause of irregular grading is the sorting of particles of different sizes by the action ~i flowing watrr. This niay liave occurred either in the present erosion cycle for transported soils, or in pre- vious c!.cles i n the c a s of strils fornietl by weathering of setlinieiitary rocks made from water sorted scdin)cnts. .\lXterial ( c ) quoted above is an example of the first possiliility, both thc saiitl-gravel antl the 1)intling siiil Iieing of recent alluvial origin. while material ( a ) . which is fnrmetl in areas wliere the doniinant rock is a massive tine sandstone. is an example of the second. Nwv tlie rate of settlement in water a t normal teinperatures of a sphere of average soil mineral that just passes the No. LOO sieve is only almnt I fcicit per niinute. of one-half that diameter only cine-quarter that velocity. of one- half that again only one-sixteenth. antl so on. I t would he most rcmai-kal,lc i n natiirc for a large volume of water to have an extremely low velwity of flow con- tinuntisly for tlie period necessary to segregate si$- cant quantities of inaterial of very fine size. The figures quoted suggest that water sorting will not be comnion Irelow No. 200 sie\.c size antl will hecome rapidly rarer as size IS further tlecreasetl. Other actions. such as \vind-sol-ting. or average size of crystal in igneous rock. may also ~iriiduce irregular grailing curves, possibly t1rnz.n tn finer sizes than water sorting. Init they would lie much less frequent.

Tlie most cxtreinr examplc oi water sorting helow No. ZOO sieve yet f o m d in New Soutli \Vales. as shown i n Table z and figure IO, is :-

i l fntniol ~ d ~ . - ~ l l l u v i a l soil in a very flat wide upland valley. catchment area granite antl con- tact metamorphosed rocks. This very unusual

. .

material has curious physical properties, and is obviously unsuitable for pavement construc- tion. I t does coinply. however. with the :\.A.S.H.C). spcciiicaticins for type F material in all respects.

New South \\‘ales experience indicates that niaterials Iiaving irregular grading curves I i e l o ~ the No. ZOO sieve are ~ i t i ~ i s ~ a l but nevertheless of ton frequent occur- rence i n this Statc to hc ignorcd in road work, so that i t is iiecessary therefore, to check tlie grading numeri- cally to a smaller size. I t also indicates that most of those irregularities occur not very far helorv the No. zoo sieve. antl tlie high cost involvetl in carrying the testing to much finer sizes justifies the sniall practical risk in curtailing tlie grading at a slightly snialler size.

A typical esaniple of tlic class of material i n question, shown in Table z and figure I I, is :-

Mrrtcritrl ( e ) .-Origin :is for material (c 1 , and pavenient also failed. Coniplies with X.A.S.H.C). specilication Type 1’ in all respects.

11 .O. specifications the principal check on the general trend ol the grading curve helow the No. 200 sieve is tlie restriction of the plastic index to a maximuni of 6 . New South Wales experience sup- ports this view. hut suggests that possibly this limit could be raisctl to 8. Evidence on this point is limited as only a very small proportion of materials tried as paveiiients conforni to all other requirements and have plasticity indices in the range 6 to 8. Pending the accuniulation of sufficient data to decide tlie matter, the Departrnent of blain l h i d s will consider the use of imterials with P.1. i l l ) trr S . hut will prefer to use, where practicable. on ly inaterials with I’.I. not exceeding 6.

There is no requirement in the A.h.S.H.Cl. specifica- tions which restricts the use of materials whose grading curves below the No. zoo sieve size have excessively steep general trends. i.e., there is no lower limit to the proportion of very fine sizes. Tlie plasticity index req~iireiiieiit sets an upper liinit only.

The Ilepartnient of Main Roads has experieilced two main difficulties in using materials which are very low in extreme fines. and therefore low i n cohesive strength. particularly when dry. Firstly, it is coiiinion practice in New South LVales to open a gravel pavement to traffic for a period prior to applying the 1)itumen surface. Materials IOU- i n titics are apt tu currugate antl unravel : heavy expenditure on \vatering and maintenance of ritl- ing surface may be necessary ; and sonietiines evcii these measures [ail t u prevent deterioration of riding quality. or even partial loss of pavement material. Secontlly. eveii after the I~ituniinous surface is successfully applied failure of the pavement untler a thin bituminous surface has occurred in dry seasons with materials of very low cohesion. I t might be mentioned that these difficulties have much less force in the United Statcs. where the generally heavier traffic volumes and tlie relatively low cost of bitumen discourage both the trafficking of unsur- faced gravel. and the use of very thin Iiituminous sur- faces.

T o iiicct New Siiutlr \\-ales needs. it is necessary to include in the specifications some requirement that will

.

108 MAlN ROADS. __ ~~ - ~ ~ ~ ~~~ .__

set a lower limit to the grading curve and ensure the prcsence of iuflicient tines for satisfactory cohesion. As with the iipl)er limit set by the plasticity index. practical considerations reqnire that :in iiidirect Imlk test I>c s d - stitutetl for the direct cliecl; of the grading curve. ’l‘lie Ikpartnicnt of Main Kmtls uses for this purpose tlie conipressivc: strength of the cotiipactetl and dried inatcrial. The niininium strength required varics with the expected or litio\vn conditions of nse. I t might be iiieiitionetl here that other Australian road authorities faced with the same l)rol)lem have also developed speci- tications :iiiiictl at cxcluding materials low in cohesion. Examples of such requirements are niininium limits for triisilc strcngtli and maxitiiuni limits for kiss i n an almsion test.

Suitalile grading. though thc iiiost iiiqmrtant i:ictl)t-. is not the only requirement for a satisfactory pavctiient inaterial. l~spericncc has shown that a prnl)crly graded material will be satisfactory in service if it is composed only of noriiial soil minerals and coarse ygrcgatc. hut not if it cont:iiiis an apprecia1)le quantity of certain objectionable con ituents, particularly if they are titially divided. hese undesirable constituents are those that, by reason of their flaky, fibrous. spongy. and/or clastic nature, interfere with the proper pack- ing, interlock, and cohesion of the soil and aggregate particles and thus reiluce both the interiial friction antl cohesion of the mass. I.’eaty or vegetable matter and mica, chlorite, or similar minerals are thc most inipor- tant and undesirable coniponmts in New South Wales.

All specifications contain soiiie requirement aimed at excluding materials with harniful proportions uf such components. Their presence cannot he determined by sicving, antl visual examination is an unsatisfactory arid unreliable guide, and separation from the mass of the soil is difticult and often impracticable. The only inethods that can be applied in practice are bulk tests on the soil, selecting those tests that are sensitive to the presence of such undesirable components. Examples of such tests are the Lower Liquid and Lower Plastic Limits, Conipaction tests antl Strength tests. Both the two latter groups of test are very sensitive to other factors. hut are not easy to apply in tlrc prcsent case, so the first pair, being simple to conduct, are the obvioiis first chrricc. I h t h the Lmwr Liqiiid Limit a n c l Lower I’lastic Limit rise marketlly i i untlcsiral)le component^ are present. the rise being more or less indicative ( i f

their harmful cffcct. Cnfortnnately these tcsts arc also sensitive to other factors. ant1 are therefore by no iiieaiis a perfrct trst for thr present purpose. 1)ut no lletter tests have yet lieen rlevisrtl.

The ~\..\.S.H.O. specifications require that tlie Lower Liqiiitl Limit slioultl not exceed 2 5 . This obviously sets an upper liniit to the amount of undesir- able coinponcnts that can he included in any given material. l‘his limit is. Iioivevcr, very different for different material ; materials free from undesirable coni- ponents and confortiiiiig to the grading requirements will, on the average. rangc from L.L.T.. 25 and P.I. 6 to L.L.L. 17 antl N.P. (non-plastic), so that the allowable rise in Lower Tiqnitl Limits ranges froin o to S (or even ninre in extreme cases). This suggests that the

Vol. XVII, NO. 4.

.A.A.S.l I .( ). sl~ecifications may I J ~ sorilewhat liberal for materials of zero or low plasticity. This is borne out by New South \\’ales experience, :IS :I nuiiil)cr of noli- plastic materials f J f satisfactory grading with h w e r Liquid Limits in tlir low twenties h;ive caused pavement failures in this Statc. The follow in^ exaiiiples. shown in Table L :ind figure I 2 . indicate this :-

M u t r y i d [, j ) .--i\ iiloderatcly plastic mic;iceous decomposed granite gravel, I’avcnicnt failed in service. C‘iim1)lic.s with 2,\.A,S, t1.O. gratl- iiig type I:, ant1 with . \ .A,S ,H.O. plasticity index reqnireiiient. l)nt exceeds :\.A.S.H.O. maximuni of 2; foi- 1 .o\ver l i p i d Limit.

Mntcrid ( 9 j .-‘\ non-plastic niicaceous tleconi- posed granite gravel. I’avenieiit failed in scrvice. Complies with :\,,\.S,kl.O, type F grading and all other A\,i\,S. K( ). require- ments ; i n particular, I.ower I,iquitl Limit is less than 25.

On theoretical grounds what might l)c callctl thc “Upper Solid Limit”, i.e., the moisture content at which the material cliatiges froni the solid contlit ion to soille other state (the Lower Liquid L.imit if the inaterial is non-plastic or the Lower I’lastic Limit if it is plastic) seems a more attractive nleasure of the presence of untlesiralrlr ~ ~ l i l ~ J ~ l i ~ l l t S than the Lower Liquid Limit. In the allseiice of undesirable componeiits, tlie Upper Solid T h i t varics much less with changes in plasticity than thc Lower Liquid Limit. The I~epartinent of Main lioarls has therefore atlopted this nieasurc in lieu of the Lower Liquid Limit, aiid from expcricncc in New South \\:ales has set ai1 upper limit of 20 to the Upper Solid Limit. Cnfurtunatcly experience is limitctl, atid the iiiumher of saiiiples on which this boundary has been set is undesirably sinall. Further experience may lend to some modification of this requirement.

One further diAiculty in this matter is tlte sensitivity of the Lower 1.iquid Limit and Lower I’lastic Limit test to factors other than undesirable ingrcxlients. These , limits are raised or lowered by differences in the grad- ing curve or differences in the shape, or nature uf sur- face u i the particles. I t is almost impossible to evaluate these effects numerically. and iiiq)ractical)lc to make pro- per allowance for them in routine testinE. I n most , normal materials. fortonately, these effects are not . uiiduly !arge. ‘I’\vo other iiuportant factors which nay produce great clianges in the Ltnvei- 1,iqiiitl Liinit :ind Lower I’lastic I imit figures are the specitic gr:ivity of the soil particles atid their porosity. if any. Specilic gravity is not dificult to nicasurc. lf it is abnurmal the siiiiple corrections can easily he made and the revised Lower Liquid 1.imit and Lower Plastic Limit figures used. The porosity correction is easy iii theory ; the \vater alxorl)ed it1 the pores should he suljtracted from the Lower Liquid T.itiiit ;ind T.ower Plastic l imi t figures and taken as part of the solid particles for the specific gravity crirrection. The tlifliculty is the prac- tical one of nieasuring the actual porosity of the very fine sizes of partick with which \ve are concerned. -411

accurate determination is impracticable though all approximate estinlate can sometinies be made.

I

’

I . 1 he importance of the Iiorosity i;lcto1- lies in the fact that materials with I)oruus particles have high Lower J iqnid Limits and Lower Plastic Limits, and materials of this type. complctely satisfactory in service, may not comply with the limits for Lower Liquid Limit in the X.A.S.€I .U. specifications, nor for Upper Solid I h i t in the 1)epartnient of Main Koads specifications. An extreme example was an unusual material used for pavement construction in New South \Vales, namely, a carbonaceclus shale, wasted from a coal mine in Iargc heaps. which had burnt by spontaneous combustion, lejving a protluct iresembling burnt fireclay of high porosity and run-of-crusher grading. Breaking up the large pieces prodiicetl a material of satisfactory grading with apparent specific gravity less than 2 , approximately 30 per cent. voids by volume, Lower Liquid Limit approxiniately 40, and non-plastic. This material In-ovetl to he very satisiactory.

There is 1 1 0 reason why satisfactory porous materials should not be used wliere they are economically avail- able even though they do not conform to the letter of the specifications prcpared for normal materials. For an unkno\vn material the noti-compliance should, how- ever, be regarded as a clanger signal strongly suggest- ing the presence of undesirable components to a harm- Tu1 degree. Tt is nccessary before using stich a material to be satisfied that the high figure is due to porosity, and to porosity onl?-. No set lahoratory procedure can lie laid tlown for this. Microsopic examination. geo- logical histor!-. antl previous service experience, are use- ful guides to a tleciaion antl a lahoratory determination of voids in the larger particles may he indicative, pro- vided they are d tlic same natnre as a proportion of the finer particles.

In addition to the preceding requirements, thc .L\.S.H.O. specifications also require that the coarse particles should he hard. tlurahle and not liahle to hreak up unrler alternate wetting and drying or freezing antl thawing. ‘TIle 1 kpartinciit’s rcqiiircments are siiniI;~r.

W‘e can i i o w suniiii~irise the total difference I r twwn the practical effect o f the twn specifications, il l so far :IS they affect selection ; i i i iI accrptance nf matcrials :--

i

I . .\laterials with normal or regular grading curves ancl free from undesirable constituents are xceptcd or rejected about equally by the two specifications. The i\.A.S.H.O. limits are a little more liberal on the low fines side, bath in grading requirements and by absence of any test restricting overall grading in this direc- tion below No. 200 sieve. The Department ui Main Roads limits arc a shade more liberal on the high fines side, both in grading require- ments and in overall control hekow No. ZOO sieve by plastic index. Few materials, how- ever, fall in the very narrow zones of differ- ence, and the practical effect of the differences is very sinal1 with regularly graded materials.

d . For materials with irregular grading curves, the Department of Main Roads requirements are inore restrictive than the A.A.S.H.O.

3. For materials of suitable grading, but containing iintlesirahle components, such as peat or mica. the Department of Main Roads requirement is tiiore restrictive for materials of zero or low plasticity, the two are equal in effect for a plastic indes of j. and the A A restrictive with Irighcr plasticity.

.is the majority of materials used. or satisfactory for use, fall i n the first of these three classes, the two specification5 c h i not differ greatly in their overall effect.

The lither imprirtaiit rlifference is that, as compared with the A ~ k S . H . 0 . specilkation. the Dcpartment’s .specification alsn in\Tillves the performance of the fol- lowing additional tests :-

determinatiiiii nf the proportion of particles than 0.0135 m.m. equivalcnt diameter.

arrietl out hy sedimentation ; approxi- mately one-third man-hour per sample. 1

2 . The detcriiiitiation of the dry compressive strength.. (Required for non-plastic samples only-average over all samples, plastic and non-plastic. allout one-quarter man-hour per snmplr.)

Tndian Road Engineers Visit New South Wales.

Four Indian enginccrs, in .\ustralia under the Mr. V. V. .\yyar. Executive I’ngineer. Public VVorks Colombo Plan. have recently lieen attached to the Department. Travancorc-C‘ocliiii State, and Nr. I). K. Department of Xlain Roatls. \‘ibhakar. Technical .\sbistaiit t o the Secretary of the

I I O Vol. XVII. No. 4. ~ _ _ _ _ _ _

George’s Kiver Bridge Becomes Toll Free

The bridge on tlie I’rinces Highway over the George’s Kiver. Sytliiey. opciietl as a toll bridge in 1929, I)ecanie toll free on the 3ist May. i ( ~ j 2 . I t \vas built by the Sutherland Shire Council and was financed hy loan. Toll receipts have been sufticient to meet all lomi iiitle1)tetlness.

The nnmher of toll tickets sold during 1930. the tirst f u l l year of olieration of tjie lxidgr, \vas Sl?.jIS. Tickets sold during i ~ j i totalled 3.235, j35. I<ach toll ticket represents uiie vehicle ; in additloti. season tickets were issued. Init the nunil)er of crossings by season ticket holtlers is uiirecortletl. There was ;I substantial drop i n ticket sales during tlie war : whereas I ,s j4.320 tickets \vcre sold in 1939. iinly 554.76) were strltl 111

‘043. koi-ge’s liiver Kritlge c~iti i~)risrs six re.j-iret

truss spans and three plate girder spans each of S!) feet 3 inchcs. iiiakitig a total length of 1 . h q feet 7 iticbes. I he piers each comprise two lintlers. fouiitled on rock. Tlir al)titments are (cif 111; concrctc hcctl \vitli santlstoiie masonry.

The roadway is 30 feet I)etween IierlJs oil tlic trus:, spans antl 34 feet I>etwccti kerlis 011 the approach slyans. .2 footway mi the upstreaiii side of the Iiridgr is S fret

I I inches wide (111 tliP apprciacli spans and 6 feet wide oi i the truss spans. 2 1 clear lieatl\v:iy of 20 feet alitr\~ Iiipli-water level ordinary spring ticks is provitletl nnrlcl- (!re truss S ~ l ~ l l l ~ .

The

,.

e

;\ propusal for a I)ridge over tlie (kvrge’s River i r r the vicinity of Toni Lgly’s. I’oint was considered :is far hack as iSi)r. Imt iio tlelinite action \vas taken at the time. ;\part froin occasional interference causec! liy \veatIier conditions. tlie irrry scrvice inet tlie ncetlh o f hirrse-(lr:iwii vcliiclrs. IHo\vevrr. with the iiitrotluc- tion of the motor vehicle the volunie uf traffic iticreasetl to such a11 extent that seriou:, congestion occurred at the ferry atid i t \vas tlecidetl to bridge the crossitlg. 111

1)rcenil)er. 1 9 ~ 3 . an . k t was liassetl ena1)ling tlie Suther- la id Shire Ctiiincil to 1)orrow tiiiriiey. take all the csseii- ti7.l strps for Ijuiltling a Iiritlge. :und to levy tolls t t i

repay the capital cost.

The tiesign of tlie b i - i d p ! aiul tlie prel):tr:~tioii oi plans ancl specilicatirins were untlertaken by the T’ulrlic \Vorks llepartment under the tlirection of hIr. I’ercy Allan. Chirf Engineer for Saticinal and I .oca1 ( h w i i t i i e i i t \\'arks. The construction was supervised by Alr. Percy .-\llan until hlarch. 1926. a i i t l f r m i theti until con - pletion lip Mr, Slienser Iknn i s wlio had assistetl Slr. Allan on the work. air11 \vhri later Iiecanie Hritlgc Ikgiiieer. 1)epartnient of Main lioxls.

Iiivrstigaticiiis to tleterniitic the iiiost suita1)lc 1oc;c- tion fur the Ijriilge wrre carried out Iietwwi-

I . ‘I‘oni Ugly’s and I Iorse R(ic1i I’niiits, 2. liricliy ant1 l‘arrii I’oiirts.

j. Ealtl Face Quarry antl E;:ingaroci l’ointx.

George’s River Bridge-Prince‘s Highway. S.H. 1 .

4

The Toll Barrier which was located on the southern approach.

‘Hie site Iretwceii T ( i i i i LJgly’s and 1 lorse Rock I’oints was selected. I t \vas considered that this site wnultl best niect tlic needs of thc public. and \roultl perillit also the tliscontinuance of the ferry scrvices oprrating lietween Tom ITgly’s antl Horse Rock I’oints ancl lietween ltocky antl Taren Points. It \vas tlecidetl later t n continiie tlir service lietween Rocky :ind Taren I’riints.

.\ contract for thc supply i d tlic steelwork for the ( korge’s River Hritlge was let to the Xrnistrong C‘rin- structiun Comliaiiy Ltd.. of Glasgow, Scotland. l’hc contract for the construction of the piers. abutmcnth. ;~pprciachcs and rrectinn of the steelwork was let to the State Monier F’ipe a i i d Reinforced Concrete \\.or!is Intliistrial Undertaking. The fi11al cost of the work \\;a.;

The fnuiidation stone was laid on the 7th June. 1924, by the hlinister for Public \I.nrks, tlie Hon. R. T. Rall. antl the Iiridge was oflicially opened hy His l ~ s c e l l e n c ~ ~ the Governnr of Sew Sriuth \\’ales. Sit- llutlle!- de Chair, K.C.l{.. on the I ltli May. I ( j 2 1 ) .

From the date of its opening until Novctiilrer. 1947. the bridge was tnaintained by the Sutlierlantl Sliirc Council. On the 0th Novemlicr. 1947. tlic care antl ccintrol of the Iiritlge (other than lighting and collection of tollsi ~iassetl to the I3epartnient of Rlain Roads.

George’s River was first explored b y Bass and Flinrlers in 1 7 y j i n tlw “Tom Thumh.“ The river rihes in the western slopes of tlir Illawarra Rangcs an(l pursues a \vintling COIII-SC fur over fifty miles beforc emptying into the I’acilic Ocean at Rotany nay. In tlie early davs of S e w South \\‘ales the route from Sydney to the lllawarra district rail Tia 1.iverpool. Campbellto\vn and .Appin, but in I 83 I tlie Survcyor- (;encral. Sir Thomas Rlitcliell, propiseetl a more direct

F.308. p).

route which lie said ”. . . . U ~ I L I I C I cross rhe lowest ford at Cook’s River ;ind (;eorge’s River l )y ferry and follow a ritlge d m v n the cna\t nii~uiitnin.” After a further survey. in I S13. \1itchell relwrted. “The passage of (korge’s Kivrr 111;1~- be e.;talAishetl at once hy a punt. as 1 fountl. at the very Iiest ~ i o i n t Cur this general line to Illawarm, olcl landing places on each side. and a road of access i i o w Iiassalilt. Cor carts antl which leads southmartl to ivlierr I proprise to cross the \\’(irnnma.’’

hlitcliell. c o ~ i i ~ i i r ~ ~ c i n ~ : frrini ~‘001~’s River. inarketi out the course of the new road to cross thc George’. River a t I .ugarn~i eight miles friim tlie mouth of thc river. . \ regular ferry service Ilegall at 1.nprmi i n 1843 ;iiitl is still in operation.

t’ollo\ving the extension ( i f ~ctt lrment at Kogarah ; incl 12ocktlale. the need arose for ;L crossing of the river tu Iic provided i n this localitv. antl in 1Ph4 a ferry was established l)et\veen Tom Ugly’s I’oint 011

tlie nrrrthcrn sick and T loi-sc liock I’oint on the south- ern side. one mile fro111 tlir n i r ~ u t l i o f the river.

The :tranjir ~iaiiic. “T(ini Ijgly’s“ is said to be an almriginal corruption of Toiii Husley. the name of an early settler i i i tlir r ( i l r i i i ~ - . N I K once lived on this point,

111 1016. :i further c r i i s ~ i i i ~ r i f the (;e(irge’h River 11) ferry \\-as esta1,lishetl I)etwecn Rocky I’oint and Taren Point.

The icri-y scrvicc at I.n.:ai-n~i is ;~tlnlinisteretl I)!- tlw Sutherlantl Shire Council. and that at Taren Point hy tlie 1)epartnient of LIain lioatls. The service at Toni Ugly’s Point was a~lministcretl 1,)- tlir €’nhlic \\.arks 1)el)artmeiit up to the 30th lnnt.. I C ~ S . and froni that date un t i l the oiieiiinv r i f the bridge iii 1929. by- the Delxartmeiit of 1T;Liii Roads.

MAIN ROADS. I Vol. XVII, No. 4. ___

by Councils

passi

Central

P ' -. . ...- [,+".,-

Oxley Highway S.H. 1 1

I

'1 T o p kff.-New England High

Crntlr IrfI.-Hume Highway S

h ' o f f o ? ~ Irff.-Trunk Road

Tot1 rt~ihf.-New England Highw

Crn I rr ?I qRt.-Trunk Road

Bvttuin right -Trunk Road

lune, 1952. ~~~

Planting ain Roads

wns

of Coonabarabran.

.".

1. 9. City of Tamworth.

Municipality of Camden.

Rth. Shire of Wade.

.9. Municipality of Scone.

unicipality of Manilla.

!ton. Shire of Leeton.

MAIN ROADS. 1 I3

c - * '*

..

Road-mixing Process Trial Length Near Maroota

.\ id1 scale trial length of 1)ituminous roatl-niix con- structioii on a country type road was recently carried out hy the 1)elrarttiient of hIain Koads l)etwern Glcnorir and llaroota. [in Slain Riiacl N o . 100. about .<S miles by road froni Sydney. It comprised 1)rrtll ii relatively thick Iiituniiniius roarl-nlis ciinrsc antl a I)ituminous rniulsiiin stal)ilisetl coiirse.

'flie rel;itively high cost i i i tlicw t y p of constrnc- tion. owing to thr amount of Iiittinien used. has hitlicr- to m;itle thcni iinattractive fiir country main road work i n New South \\'ales. Ilut with the esllaustioii oi local iii:itcri:ils i i 1 first qudity iii ;i iiiiiiiber of areas. tlie stagr liiis noi\, lieen reached where these t\vo tyl'cs of coli- structioii. i n certain r;ises. tilerit econotiiic coiisitleration. In order therefore to chtain information o f the plant requirements ant1 outliuts, and tlie most snit:il)le iilixinx technique antl likely costs uiitler local crintlitions. trial lengths were laid i n the autunin of 1 ~ I j I . 'Tlie wnrks were seriously tlainaged I ) ? min that fell tltiring and after construction. but the objectives were acliievcrl antl it \vas possil)le to obtain rc1ial)le estiniates oi plant requirenients and oiitputs o I i itdl wale work and tlevrlop suitalrle techniques. The rain \vxs [ i f valuc to the extent that it enipliasiictl tlir cliniatic (lil'tirtllties which :ire always likely to occur with nwl-ni ix ciinitrnction in this Statr.

I he ninre southerly trial consists d ;ipl)roxiiiiatelv half a mile of surface cn~i rsc \\it11 :I seiiii-rrj)cii zrarling of

I >

tine ii-ec. saiitly gravel road-niixetl with fluxed liitunlrn ( apprcixinlatcly 93 per cent. passing 3-16 inch sievc. j o per cent. liassing No. 25 and X per cent. passing N o . 100 1C.S. sievc I)lns 7 per cent. of hitutuen plur flus as required. ) 'This was mixed with two gradel-s and ii

rotary hiw. slireatl. allowed to aerate until sufticient flus had evapiiratctl. ant1 finally rolled to a ciinipactrtl thickness of 3 inches. Continued rain prevented tinisli- itig off at the correct time at id trial compaction. when ii siiitalile consistency was reached, showed that thc mix was danip so tliat it liatl ti> he re-opened f o r evapor;i- t ion . 13y the time the material h;id dried ont t r i o InLich Hus Ii;it l Iiceii lost ; in( l , with the onset of cirlrler weatlier the inis \\:is t o t i stiff to \ v d ; inc l ciiiiip:ict properly with tlie aratlcr atid roller. .\s :i conseqne~~ce the fin- ished surface is iiiidesiral)ly rongli. .\notlicr defect il l

this trial section is excessive hlcediiig in pl:ic-es I)eciiuse of errors niatle in the ~ ~ r ~ q m r t i ~ i n i n ~ c;i I)itnnien to aggre- gate tlrie to unfiiresecn difficulties in tliih typr cif work. Seitlier of these two tkiccts shociltl occiir under nornial weather contlitirin.; and \\it11 the r,sliuience now gained.

The t\vo ticirtherl! sections Iii i i l)ouI ;i iparter of a mile each tverc FyperYintwts in I)ittuminous stabilization [ i f a stony soil sliqhtly too chyey til makc ;I satisfactory rilatl grnvc.1. Slow Iii-ealiing 1,ituiiieti-rtiiulsion \vas nsed. t l i ~ niising being done on the I . ronil I)! two power graders and two rotary hors. I hc nlisetl material

Pavement material spread ready for sprayinp; with bitumen.

1 I5 ~- -

June, 1952. MAIN ROADS. ~ __

\vas riilletl tci a cotiipactetl thickness of 3 inches. The soiitliern half of the more southern of the twci section.; Ilecanie (ivcrwet 1icc;iusc of an overnight shower. and subsequent mixing of this portion was difficult. The oiily other difficulty experiencetl during construction was in keeping a steady ‘prayer speed when q)erating on the hilly ntirthet-n section.

On c~inq~le t i i i i~ , tliese scctions were left t o (lry (itit i l l

;iccor~Ia~ice with iiorni;il Iiractice c o that the emulsion woiild Iii-cak ; i i i d the iil;itt.rial 1)ecoiiic xtal)ilisetl. Iiut continued rain i t i the late autiuiin kept the mix wet until wiiiter set i i i and drying (it11 tl i I not takr place till well 011 i i i t i i sliring. .\fter the tlryiiy in i t . ;I Iiitumiiirius surface \vah aplAied in t h r iisiial w a y .

Mixing with bitumen, using

hoc.

-

fluxed rotary

From time studies made during the progress of the work, it was tleterniinetl that suitalile 1)alanced equip- nient for work of this nature would be :-

I a ) Rond-rrri.r Siirfac-cs Cotfrsc. I K o o gall. callacity bitutiien sprayer. I fluxing unit 3 heavy duty- power graders 2 nrtary hoes self-propelled j feet wide or one

rotary tiller feet wide I Iiower ciperatctl siiiooth whrel roller I O / I Z

tons. Siiitahle e q u i ~ ~ i i ~ e ~ i t for loading and delivering

inaterials (aggregate and binder) and for ciinstriictiiix shtrultlcrs.

Spraying of bituminous emulsion.

~~ __

MAIN ROADS. Vol. XVII. No. 4. -~ ~ .~

Mixing with emulsion in progress.

This equipment allows for final preparation of the Iiiise Iiut lint for its initial construction ani1 shaping.

The :ipproxiniate output of this oramisation under norinal conditions \voultl lie about 3,000 to 3,500 square yards of pavement per (lay of 3 inches coinparted thick- ness.

( I J ) E~iir t ls ioiz stiihilisnfioii. I SOO gall. capacity Iiiturncn sprayer .+ licavy duty p w e r graders z rotary hoes self-liropellecl .j fcet wide or one

rotary tiller 7 feet wide 2 Soo-gall. watering lorries

I pneuinatic t!-retl roller drawn by water lorry).

Suitable equilmtxit tur luadiiig ant1 delivering materials (soil and emulsion') and for constructing sliouldm-s.

This cquipnient also allows for final prepr;ition of the base liut not its initial constructiotl ai i t l slialiing atid not for the bitumen wearing surface. The (nrganisation c;in treat approximatcly Z , ~ C K ) to 3 ~ m o sqii:iw yards of .{ inches thick compacted ~~avei i ient pcr [lay \vhen staliilising soil of the nature treated i i i the trial length ( soil required 5 per cent. by weight of rnicllsion with some niargin for field variations).

Section of completed work.

June, 1952. MAIN ROADS. ~~ ~~ _ _ _

Steelwork from Overseas

For Pacific Highway Bridge Over Entrance to

Lake Macquarie at Swansea

View of openinp span after completion of temporary erection at works of Contractor. Maschinenfabrik Augsburg-Nurnberg (M.A.N.) , Germany.

(February, 1952).

Unloading steelwork for approach spans, Darling Harbour, Sydney.

U

Vol XVII. No. 4. __ MAIN ROADS. _ _ ~ ~- I I8 __

Organisation of Plant Maintenance and Repair

I t is axionlatic that pl;int kept i l l good condition will illrerate at nlaxiiiiulll elliciencp antl to ellsure this i t is essential to have adeqiiate provision of plant main- teiiiuice antl relrair facilities atid efticient supervision ant1 planning so that such facilities are used to the 1Jcst advantage.

The 1)epartnlent oi hlaii l Ki)atls has local ofices ani1 depots, some pernianent antl some teniporary, located tlirorighont the State antl from tliese, the various works, I)oth iiiajor ancl minor, of road arid bridge mainteii- aiice atid construction are directly controlled by engineers or foremen. The local ofices and depots forin tlie centres of operaticin of groups oi plant from small to large. ;u id facilities varying in degree are pro- vitletl for plant niainteiiancr and repair. In addition. each plant item is suliplietl with service charts. ~iperators’ itistruction I)ooks. a kit of tools and lubri- cants so that nperatrirs are able to uiirlertake the lubri- cation. niaintenance anJ running adjustments.

1 he equiliiiient provided with each plant item, ancl the facilities at each local office. tngethcr with service which may be availalJle from other Goveriimeiit 1Iel)art- ments or private enterprise in certain areas. eiiablc atle- quate iiiaintenaiice and repairs. mainly oi iiiinor nature. to be untlertalien in the field in close proximity to jnbs OII wliich the plant is engaged.

l’lant items worked hard :mtl contitiuously over Iirng periotls gratlually deteriorate to such an extent that fre- cluelit 1)reakdowiis atid resnltant disor~aiiisatioii in jobs arc cxpericncetl. antl they require niaj(ir overhauls wliicli are he!.oiitl the rcsoiirces c i f thc field organisa- tions t o undertake.

I’latit i t e m requiriiig iiiajor ~irerliaul are returtietl to the Ikpartiiietit‘s Central \\.orkshop at Granville, Sydney. where they are completely stripped down atid rebuilt. .A high standard of repair is aitiietl at so that each plant item is iii near IICW condition on completion of tlie repairs and fit to give long. service in the field Irefore requiring another major overhaul. thus avoiditil: frequent costly tran.;port charges froill a l l p:irts of the State t n Central \\~orlisliop.

.\t times tlic volume of ivork at Central \\.orksliop is such that it is necessary to iiiiilie arraiigeineiits with private enterprise to sulimit quotatiims and nntlertake sniiic (if the tiiajnr overhauls. I n these cases supervision is effected I J Y 1)eparttiiental Inspectors in order to ol)- tain a similar stantlard of workinanship to that achieved 111 the Dcpartiiiciit’s Central \\;orksliop.

Field Workshops.-The types atid numhcrs nf field ivorlisliops estal)lishctl I)? the Department are as

I . hlinor I\Jorkshops . . . . . . 20 2 . Travelling \Vorkshops , . . . 3. Major Workshops . . , . . . h

?.

4

0

operation. 1 ’eriotl which plant will lie iqieraietl in area to complete the job. I h t a n c e friini facilities c i f private, riiterprise 01- irtlicr ( ;i)vcrnmeirt I )cp:irtiiients \vhich have cal)acity to tltltlertalie repairs. \\:hether plant is located iii coiiiliact :irc:is or dispersed in groiips i i1 one or twir units over w r y extensive areas. Whether :L nitrtlerately large groiq) C I ~ pl;uit is engaged on a fast moving roadivork neces- sitating frequent moving. of tlie reiiair facilitic3.

( 6 ) ‘Thc nunher of titters available f ( ~ r e n q h y -

In lit-actically all areas where pliiiit is i n use :I tiel11 \vorksliop of some tlescriptiirti has beeii ehta1)lisIietl li! the Departiiient. ’The irnly exceptions are where one or t n ~ i plant itenis are engaged in a remote area on work oi coinl)aratively short tluration. In these circunistatices new plant or plant wliicli has lieen recentl! owrli;lulctl is selected for the work so that niaiiiten;uice IJY the operator is soilicirnt to ensure efficient i ipcratio~~ tir completion of tlic work.

l l i e contlitioiis ill each arca have to I)e carefull> ccinsitlec-et1 I i~f i l re tlic iiiost suitalile type cut’ w ~ i r k s l i o ~ ~ is deterniiiietl. 17yen after the most suit:ilrlc type r r f workshop has lwei1 selrctrtl it is still tiecessary to tlecirlt, \That eqiiipiiient is to Ire supplied as it is not practicalrle to staiitlartlise tlie eqtiipiiinit for each type (if work- shop. ax this must vary with local circutiiht;iiices except in the case of Travelling \\‘orksliolis for \vliicli equilj- tiient has hecti staiitlartlisetl. Fur instance. if a Miiiiir

I\’orkshop is consitleretl suitahle for a partiriilar areti it will Ire iicccssary t u provitle I i ;~~~tl-o~~er:~tet l , cngille- operated or electric motor driven tools. according to the roluinc of wiirk t ( ~ I K uiltlcrtaltrn or tlw av:iil:iliility trf local electric poirer supply. Again. thr su~qr I \~ oi soiiie items ma)- l)r not cssctiti:il as I i i r : i l fncilitirz already i n the area c:iu cater for some rqiair rrcltiii-e- iiienth. ’fhe saiiie remarks apply t o l l a jo r \\~~rrlisli~ips.

The majority o f field WO ;ire priivitletl with ;I

Minor tf’orkshop cotiiprisiiig a siiiall lriiililiiig of sulfi- cient size to arronunotlate the equii)iiiciit and t o c i l ~ q)plicrl ant1 t o Iirrmit of one or two litters workiiig on cmipotieiit 1)arts of plant itrms. The ~lisiiisntling a id assenil~ly of tlie plant item is uiitlcrtalicn cintler tar- p:iiiliiis in the open.

’Tr:lvellin: norlisliolrs. coiiiprisiiig a large stccl I~otlv fitted on a 4 to ;-ton lorr!., are provided when small plant groups arc tlispcrscc‘l over a very \ride arca or

ment ant1 the capabilities of those etigagetl.

_.

MAIN ROADS. 1 I9

Portion of Machine Shop, Central Work-

shop, Granville.

~ I i e i i :i I ; I I - ! ~ iiiniilxar of plant unit5 is cnfi;igcil 011 :t fast-iiicivii~~ I-oat1 jnh. l'lie Imtly of the 'I'ra\dling \ \ ~ i~ i -ksI i iq~ is sntiicient to house the equipment and tools. stores. and nl) tri twr litters repairiiig ctrn~ponetit parts of plant.

Major \\'orltshops are provitletl when a large groul) [ i f plan^ iteiiis will l>c i n oper:~tion for a long period iii a particular area and the work is remote from facilities c i f private enterlrise or iither Government Department having the cal'acitv to midertake repairs. The huiltl- ing is larger than that h r a mintrr workshop antl will ~:cconimoilate niore in;rcliiiie and hand tools and room to house one or two niajirr plant items as well a i litter. ctigagctl mi repairing cnmpi)nent parts.

Equipment for Field Workshops.-The iiiacliine and hand tools, stores ant1 itiiitlry spccial eqiiipment will. as explained Irreviously. vary. The noriiial equilniicnt antl stores slipplied ior each type oi wc>rksliop is set out hereuntler. Store\, cr~niprising espciitlable materials aiid spare parts. will be located in the Local ( Ifice store together with iitlier riiatlwnrk stnres when fixed Minor and Major \2'orkshops are established. In thc case of Travelling \\70rkshops a small supplv of stores is carried with tlie \vorkshop.

A. MINOR WORKSHOPS-EQUIPMENT AND STORES.

A. (i) Equipment-Located in Workshop.

Fitters' Benches J'yces. heavy d u t y j in. . 6 in. with offset jaws. (;rillding Machine. electric. two S in. to T O in.

wheels.

I )rilling ll:iclii~ic, rlrctric, 3.5 in . Iieavy duty con- pletc wit11 Iic~icli stand ancl twist drills.

Drill, breast. o to % in. f'ortalile 1ll;iclismith's Forge. anvil and tools. Welding Sct. oxy-acetylene. Sledge I~animer . cross-cut saw. potlger antl pinch

Cylintltr Sleeve Extractor. Sockets sets for .C...\. IC. aintl \\-hit, liolts up to

Spanners. King. S..4.1<. for liolts tip to I in. rlia. Spanners. T).I<. for S."l.lC. aiitl \$'hit. bolts up to

1% in. dia. Wrenches. Stillson I S . in . , ('resccnt -71 in., Multi-

Grip 9 in . \Vrenelies. Talipctt. lizyonts. Set. :/4 i n to .+$ in. Reamers. expantling. Cnivers;il metliuin (It

gears, etc.. w i t h . Chain Bl(rch-. 3-ton. including slings. Hydraulic Jacks. j-ton and Io-ton. Blow Lainp antl Siiltlcring 1 ron. Measures. Oil-r pitit. r quart. r gallon. ~iiniicls. filling. oil ani1 !>etrnl. ' l'iinips. I land. for +-gallon drums. Set of Fitter's Tools-such as hammers. cold

cliiscls. screw-tlrivcrs. pin punches. hacksaw. pliers, feeler gauges. rules. tinsnips. scrapers. calipers, etc.

1,al.s.

I 2 in. dia.

wheel puller for timing

I20 MAIN ROADS. .--

Vol. XVII. NO. 4.

A. (ii) Stores-Located in Local Office Store.

t;iles, all types inchtling thread files : Iiolts and nuts; Briglit steel, S.A.l<. antl \\.hit. ; S a screws ; Metal thread screws; Castle nuts ; Washers, flat. spring antl fibre ; Split pins : Morse taper pins; Square steel for keys; Rivets ; Hacksaw blades ; Grease cups ; Grease nipplcs, assortetl Zerk, Tecalmit, giant button types ; I’acltings antl jointing ilaterials, cork. lilire. riil resisting, greasy lienip, hcat resisting. steam. red lead, litliagr ; Copper tuliing ; Pipe iittings. small diameter. unions, elbows. cocks ; Sheet copper ; Gal- vanised irtrii ; ‘Tinincti’s rivets ; Friction tape; r\tlhesive tape ; l h e r y cloth ; I<niery tape ; Brass and steel for sliitiis ; Cotton waste : Stockingette ; Valve grinding paste ; Solder- ing flus ; 1)istilletl water ; Gasket cetnent : “Wostick” cemcnt ; .\sl)estos Ii;icking ; 1Iatli;itor hose ancl clips, assortetl bims : II’eldiiig I-otls :1nd fluxes.

1;ast-movitig spar<> parts such : Special nut.; atid bolts as for grouser plates. etc. ; fuel antl oil filter elements ; fan belts ; magneto and rlistrilmtor puints ; cylinder, iiiatiifnl~l, siiiiip. etc.. gaskets ; air cleaner aiitl petrol filter glass I~in.ls ; circlips ; Irather, caiivas and rnlher

1)elting ; be11 fasteners ; spark plugs ; generator Iirushes ; Reynolds type chains. etc.

B. TRAVELLING WORKSHOPS-EQUIPMENT AND STORES.

B. ( i ) Equipment.

shops with the following ntltlitioiis :- Similar IO cquipniciit i u r n i s l d with Minor I\’ork-

,i K,\’..\, I’etro-driven A.C. (;eiieratiiig Set to operate macliine tools.

6 in. tu S in. T.athc. nlutor i ,d . conililetc with all accessories. straight. 1I.H. antl I,.H. offset tool ~ l ( J k ~ C l 3 , lioring I)ar and holtler, parting tool holder. ;issorted Iiigli-~pced tool bits. thread chasers.

’rod I’ost Grintler. \’alve S a t Grintling Rlachitic with grinding wheels

;nid pilots. loo-goo amp. D.C. .\rc \Velding Set-either

mounted on \\‘orltshol) or Trailer niounted.

Arbor liench press

Heavy (luty portal)lr rlrctrir grinder. 6 in. dia. s 1-in. n.heel.

AIR CONDITIONING PLANT

UBLE ENDED BENCH GRINDER B‘DIA W M E L

W A R D WITH PLUG IN FML 2 4 0 Y TOWN ~ ~_ SUPPLY

LATHE ACCESX)OI PETROL ENGINE 16H.P

JAWBEYCH-VYCE

OCWIIIYE*I or W#* ewD5 HIW

CHAIN I ROPE_BLO . ~ ~

June. 1952. MAIN ROADS. 121 - - _ _ _ _ ~~

. 1

.. 1

Exterior of Field workshop on road construction work.

B. (ii) Stom. Similar range to Minor Workshops but smaller

qnantities to reduce weight. In addition. the following materials to bc on hand for use with the lathe :--%lid and cored bronze stock and Briyht M.S. shafting of assorted sizes and flat kr.s.

C. MAJOR WORKSHOPS-EQUIPMENT AND STORES.

C. ( i ) Equipment-Located in Workshop. Similar to that provided for Travclling Work-

shops. except for tlw followin:: additions :- 15-25 K.V..\. diesel engined generating set in

licu of j K.V.A. set to supply camp lighting in addition to workshop 1-equirements. Unit supplied only if no local electric power supply is available.

ho-ton Hydraulic Press. Steam Cleaning Unit. trailer mounted. \;alve Refacing Machine. complete with stantlard

grinding wheels. Garage type .Air Compressor Receivcr Set with

high prcssurr 1ul)ricating giins. trailer mounted.

Battery Charger. Post Drill. h;iiirl operated. I cnliacity. with

ratchet feed. Stocks and Dies, S.A.E. Taps and Tap \\Trenches, \Vhit, and S.X.E. Ilie Nuts. \%'hit. and S.A.E. Xficrometer Set. inside 2 in. to 8 in. Microineter Set. iiutsitlc o in. to h in. r'yliiider CoinpreArr Gauge. lievolution Counter. High Rate Discharge Voltmeter. Spray Painting Gun complete with air cleaner and

and air regulating valve. Heavy duty \\'heel Puller with standard atlaptors. Electric \,.ulcanixr.

Special plant tools demanded as required-supplied generally on loan only.

C. (U) Stores-Located in Local Office Store. Similar range to Travelling \Vorkshops but held

in greater quantities to cater for larger group of plant items.

PLANNING OF PLANT REPAIRS. In undertaking plant maintenance the following prim

1. Good Planning is essential to:-

ciples must be kept in mind:-

( ( I ) effect minor repairs as soon a5 required and thus nraintain the plant in good condition with resultant high work output and also ensure that unnecessary damage to other parts will not result in breakdown involving major repairs, lengthy joh interruptions and the unneccssary supply of valuable and scarce parts and absorption of fitter man-hours ;

( b ) permit periodical major repairs at the Cen- tral Workshop to fit in with road works pro- grammes so that major breakdowns in the field are kept to the minimum and valuable field fitter man-hours are conserved for the important work of preventative maintenance and minor repairs:

( c ) reduce time taken for minor and major repairs to obtain the maximum output from the plant fleet which represents a large capi- tial investment.

2. Good Planning can be obtained by:- ( 0 ) plant operators reporting noticeable loss of

plant efficiency and wear so that action can be taken to obtain parts and make a fitter available to undertake repairs speedily to suit the road work organisation :

( b ) plant opcrators faithfully observing the requirements of the service charts in regard to lubrication, maintenance and adjustments so that normal operating periods are obtained from the plant before niajor attention is required ;

(r'l supervision of I'lant Operators in regard to ((1:) and ( 6 ) by Road Gangers, Foremen and Engineers. assisted by Inspectors and Engi- neers from the l'lant Section;

( d ) periodic assessment of the number of titter inan-hours required to effect the repairs to all items of plant enyaged on each road job arid the transfer oi plant items involving major repairs to Central \\'orkshop if the I:)eaartmental fitters and private enterprise facilities available locally are unable to effect repairs within a reasonable time ;

( p ) the early examination of seasonal use plant at the end of the season to determine repair work required, obtain required spare parts atid have the work rinrlcrtaken so all items

I22 MAIN ROADS. Vol. XVII, No. 4.

Repair work in progress at Field workshop.

can lie p i i ~ t o use at the start of the next senscln ;

( f ) close watch ( i n issue ( i f spare Iinrts fro111 the Loc;il ( Mice store to tletcrminc usace rates :ind ensure that adequate stricks of fast iiiov- ing psi-ts arc :twildile \\lien rcqiiiretl : iiiaiiitaiiiiiig at C'ciitr:tl \VorksIioli Store :L rcccirtl of a11 sliart' I):irts i i h d lor tlic main- trtiiiiicc i i i i d rcpair of all itcins in tlie 1)eliart- iiient's Illant fleet so parts caii l)c siipliliecl iroiii stiicli to any 1i:u-t i i f tlie State viitliin 24 lioiirs : hiiltling iii stock at Central \\.orkslinp recon- tlitioncd unit assemblies availalile for replace- ment of similar asseiii1)licc (111 plant oprratiiig iii the field ; the old :issenil)lies Iieing returned to Central \\'orksliop for I-cc~rntlitii~ning au(l re-issue as rcquire(1. 'This is 1)eiiiK (lone for parts swli as :--l)icscl fuel iiijectiir.;. siilicr- cliargers for tlicccl ctiginrs. cr;i\vler track assetiil)lies. inagiieto~. etc. This I)roctylurc- results in saving ( ~ f field litter i i i: i i i- l i[ inrs ant1 :I large cspeii[liturc o i i czpeiisive tool5 which \voultl othcnvisc rc(1uire tlihtriliutioii t l i ~ - o u ~ I i - n u t the State:

1 i ) maintaining a record of hours ivorked since tlic last major overlianl Iiy cacli tiiajor item of l)laiit. in the I'laiit Section at Head Oftice. tlins permitting tlie recdliiig U i plant for major overhauls at C'eiitral \\'orliehop before major troubles are eqiericncetl i i i the field. This record \vi11 also assist in deciding \\lictIicr plaiit broken (l(i \vii in the Iieltl s h p l i l ,

lie re1)aired in the iieltl or at Central \\'orksliop. 1 1 is cif little use relxiiriiiK oiir Ixirt of a plant itciii in the field if thr Iioiirs \vrirl.;rtl itre such :Ii:ct earl!. trouble c;in lie eslicctctl \vitli iimierotts other parts of tlic iiiacliine ;

( j ) tleterniiiiitig order of uiidrrt:iliiii: plaiit repairs to suit road works and tlieii permit- ting repairs being uiitlertakeii witliout inter- ruptioii. Frequent interruptioii to repairs not only increases the cost of iiitlivitlual repairs hut results in a seriow decrease in the number o f units it is Ixissililc to rcc~iiitliti~in with the I)reseiit-tlay liniited facilities.

I I1c experience ( i f this Department sliowv.; that under present-tl;iy conditions the proper care and inaiiiten- u icc ol lilaiit is difficult to olitain even with adequate worlisliop facilitics unless ciiiistnnt attention is given Iiy all coiicrriietl to the points essential for good plan- ning of repairs.

In a few cases where the Ikpnrtnieiit Iins supplied \vorl<shop equilmicnt (in a scale similar to travelling anti mobile \vorksliops it has Iiccti iowitl that the on-cost charges. expressetl :is a 1)erceiitage of fitters'

Iiavc Iieeii excessivei (Iiic to thc rmavailability rielit litters to \virl . ; iiiitler lieltl coiiditioiis. i\

c h e \\-:itch is kept on this aspect : i d it is uiilikely that many atlditioiial w i i r l ~ s l i ~ ~ ~ ) s will be sulqilied with facilities to the saiiic esteiit as I la jor \Vorkshops. It is considered that thr trentl will be to supply field workshop facilities in the f o r m of a 3-4 ton lorry. con- tainiiig shcar legs, 3-toii chain block. liytlraulic jacks. fitter's hench. large offset vycr. liaiirl-operated emery wliecl. oxy-acctylene vdtlilig set. stocks and dies. reamers. taps. socket ivrciiclies. ring slianticrs. set spatiiicrs, Iircast tli-ill : incl other siiidl titters' tools. In some areas a light \\.eight electric arc wcl~ling set atir l :I light caravan for the litter atit1 titter's assistant may lie justified.

The S L I ~ I ) ~ ! . I ) ? facilities 011 tlicse 1iiic.s will decrease c:tpital outlay and iiicmisc iiiiiliility. I t will. however. rlccrcase the extrnt of rcl):lirs ivhicli can Iic effected ill

the field and iiec .itate I IN, iiiorc irecluelit returli of Illant til Central Worltsliol) for major repair.

, .

June, 1952. MAIN ROADS. I23 ~. ~~

~~

Military J Engineer Units of the Supplementarv J

Keserve

I ) c v c l q ~ ~ ~ ~ e i r t s in niotlel-~r \vxrfarc have led to CUII- siderable emplia~is beiiig placet! on engineering \vorks iir the IJ;LW :tiid co1ii1iiu11ic~itic~11 areas of ariiiies. In \var. eiiginrci-ii~g w ( i 1 - 1 , ~ in for\vartl areas have :il\\-ays lieeii tloiie I J ~ military engineers ; Ijut ~ r u r k s in rear areas. which u m l not to l ~ e of :in urgent nature, have 11ftcn been Iiantlletl by til-il authorities. or by civilian Ia1)oiir under :\i-niy rlirectiirn. However. in the 193y 45 war there \vas an un~~r~ce t l rn t ed dcmantl for air- fieltls. strategic ro:i<Is. IJiirts :in(l other works in rear areas. aiitl maiiy of these works weiw so urgcntly

cnult! not lie prcitluced in the time . 'I'he result \\-as ii marlietl iticrcase i r f ctigirieers in the Army. and the

adtlition to the order of liattle of construction unith with the special task of rapid cotistructiun in rear areas.

In .\tihtralia. wlien the threat of invasion i n 1941 illcreased the tlematirl iul- civil eiigiiieering- ivorks. there was time for the defence authorities to arrangc with the larger governmcni ~~rgaiiieatiiriis. normallv occupied \\-it11 tlic coiistruction atid maintenxiice of pulilic utilities. t o undertake tlir construction o f n i a i i ~ of tlre airstrips. strategic roads. tlocks. and ports required 0 1 1 the 111aiii- I:tnti c i f .\uxtralia, ant1 i i i i s ~ i i i c i r f the islalltli in the I L1 rilic ' . )ce:ui. 'l'lie rt:cortl of the Ikimrtliient of Main liiiatls ii i this tielrl is tle~crihed in "

tenil)er a n d I)cccn~l)er. 1046. ( h i tlie (Ither hand it tlries appear that i n R fiiturc eti iergetq~ thei-c ma!' not

be this tiiargiii of time, antl that urgent defence works within .\nstralia. in nearby territories and in oversex tl1e:itrt.s will have tu be rscciitct~ at short notice by engiireer units which shoult! I w trained in peace for that pi-pose.

These niatters have hail serious consideration by the Institution of Fhgiiieers. .\ustraiia. antl as reported in the journal of that body CJIi l'age 55. Vol. 2 1 (l larcli , 1947) it appoiiitetl a special Coininittee to esaniine ways and means of ensuring there would he

anizations t o Iiriwitle large scale en- in tlie event of \v:tr.

In I)ecember, 1948. the C'ouncil of the Itistitution forwarded a 1iroposal. t o the Minister for the Ariiiy. fur the formatiim of engiticer units oi tlie Army on an active reserve Iiasis under the sponsorship of Govern- ment 1 )epartnieiits. Such units would be part of the Citizen Military Forces Iiut woult l have special terms of s e n ice OII the lincs oi the Supplementary Reserve in the United Kingtloin.

The 11Iinister for the I\riiij- almrovcd the proposal and by arrangement with the State Governments of l'ictoria and Ncw South \\.ales siipplementary reserve engineering units have Iieen set Lip in each state. 'l'lie iiiteiition is that tlie units muuld he formed of recruits from larger State Government organizations concerned tvith the c~~nstruction and maintenance ot'

A squad of N C O . . moving to training.

~ - - MAIN ROADS.

, .

Vol. XVII, No. 4. .

Recruits receiving Bren Gun instruction.

_ _ - ~

Training in assambling and use OF heavy

bridging equipment.

- -- __ -

June, 1952. MAIN KOADS. ~~

I25

The catiip ~ v a b ii succcss i i i that at tlic curl of thc fortnight tile iiicii had stttletl down into sqiiac1rons. antl had h r n t or Ibeen retresried it1 the elements or iniautry : t i i d engiiiecring ivork. 'l'ile unit undertook the coil- struction of a sports oval at Middle I Iearl antl liefore I)i-eaking ul) lml coml)letcd the desiKii m c l in l'art the construction. The work was later finished Iiy a regulai- army unit atitl tlic oval will shortly lie in use.

The second ramp was heltl at North Fjcad. Sydney. in ; \ l i r i l - lk iy . i y j i . The policy \vas continued of I raining the i i ir i i it1 chmrntary drill and eiigiiieeriii: txslis ;unrl giving tuition in the liantlling of plant to thosc not regularly engaged on such nm-k. Other thaii iis iiistructors. rcgtilar plant operators did not hatidle

Ihriiig the year I~etween the camps tlir Snowy Mowitaiii Hyrlro-l+ctric .\utliority was invited by . \ rmy to s1ioiisor a special reserve unit antl it organized a cotistructioti squndroti which was placed oiitler con- m m t l rif the 2Ist C'oiistructioii Reximetit duriiig the catnp

r l ruiy also apl)roaclietl the Shires antl certain Mimi- cipalities it1 New South \\'ales and suggested that these Irtrtlies allow their employers to join the 2rst Cnnstrcic-

plant.

tioii Kegiiiieut. l'lie enlistiug of the shire employees \\as to i)e untlertalicn by ttlc Ikpartincnt ot Main Koarls. tlw h1ioiisoriiig Iklrartiiient. and any shire em- ployees joining \vci-e t o lie attachctl to Squarlronh furirretl liy that I kpartmcnt. . \ sprinkling of Shire employees entered the 1932 ca:iip ant1 it is expccted tliat their nuili1)cr~ b r i l l iucreasc at the next camp.

.\s far a.; possiible the Regiment endeavours to run i t 3 ow11 atTairs as woultl be the hituatioil were it on x t ive servicc. I t has. Iio\w\w-2 to lean heavily on a corc d regular aruiy soldiers, especiall!- on the atl- jutant and quarterinaster sides.

The strength or wealiricss of a Construction l<egi- tileiit lies in its noli-coinmissioiied officers. The spoil- soriiig authorities have a tiuinlxr of al)lc loremcn. overseers and gangers antl a number of these have cnlisted. Every cffort has ticen made to inculcate these inen with tinsic tnilitarp traiiiinx with a view to their hccotiiing the NCO's of the unit.

A survey after two years shows that the Supple- mentary TJiiit i n S e w South \\'ales is a success and the extension of the scheme. as envisaged 11y the Insti- tutinn of Ihgineers. appears justified.

__t_

PAYMENTS FROM THE ROAD FUNDS FOR PERIOD 1st JULY, 1951, to 31st MARCH, 1952.

.\mount Paid ( 'OlJNT\ . OP C'VMBBRLASD kr.IAIN I < O A n S 1'LTND L

Construction a i i d rccrinstruction o f Roads and Bridges Acquisition of Land and 13i:ildings for Road \ridenin: Maintenancc and minor i~nl,rovo~ncnts of Roads and Bri Intcrcst, EschanKe a n d Krpaynimt of 1.oans ....................................... 67,oc.t Other I'xpenditurr ......................... l<,j.o:'

.................................. :1,703,687 ~

COUNTRY M A I N RnAns FUND : Constriiction antl rmx,nstroction of Roads and I3rid;c.: ........................... I ,;3ci,qi I

Acquisiti<in of Land and Ihildinjis lor Road \Vi<lenin:. - 1.5.9o3

I n t r r r ~ t , I:uclianfe and Rrpaymmt o f Loans ........ I 1o,qo5 \laintznance and minor improvrnicnts of Roads and Rric gcs j , O / ~ J . f > R j

................................. I'nrchase anrl repair of I'lant anrl 3lotor Yeliiclec 73 1 .4SS O t l i c , r I<sl)enditiiri. ........................................................................... ~ ~ o , u . i t ,

'I'ot:1i ................................... t5 , '447.93~ ~~

O I ~ E N ' L . \ I . I<w\i~b l i i . ~ ~ ) : . . . . . . . . . . . . . . . . . . . . . . . . . . . t'crn.;tructicm atid rt,cnn\troctinn of I<iiads ancl I{ridgc\ h.3.lirj

Othc'r !Ixpenditul-r ........................................................................... 6.50 ~

7'i)tai 1JX&lO"

Sunlsi.AR\ .\LI. I;< AL)h

C~mstroctiini and r~~rmslruc.t ion 1)f Itoad.; i i i i t l ltriclgv. . . . . . . L , i j 7 , 2 4 '

.\cquisit iuii of I,aiid and 13uildinjis for Road IVidenin:: t(J.S(J4 hlaintmanct, and minor impniwments of I<oads ani1 I3riduc.i . . . . . . . . . . . . . . . . . . iIO7.i.7.i5 Intrrest. lixchange and Repayment of I.oans ....................................... I j7 ,qoq l'urchaw and Repair of I l a n t and 3lotor \'ehiclr~\ 73 r,qqX fl thrr I.:xprnditiir? . . . . . . . . . . . 426,757

..........................

................................

.................................................................. I',,tnl t7,(135, j z j

I26 MAIN ROADS.

Main Roads Exhibit Const rwction Industries Fair

i\ C'uiistruc~i~m tntlustrics ];air, ivith which \\ab associated a Construction Intliistry Convciitioii. was held in Sydney from tlie 8th to 15th ;\pril, 1951. 'l'lie Construction Intlustries Fair was located 011 an area iri Moore I'ark adjacent t n the Sytlney Showground. where the annual Royal :\gridtiIra1 %J\V \vas in progress.

The Fair iiiclutlctl extctisivc tlispl:tys U[ cnrthmnving and other constructional eqtiipiiieiit. to a large degree nianufacturecl in Australia. together with exhibits by ( ;overiinieiit:il constructing authorities.

l'hc Ikpartmeiit of Main Roatls exhibit \vas divided into two Iiarts. -\ large niarquee housed display cabinets of colorired photographs on gl froiii beliintl. illmtratiiig the tlevelopment of roads and 1)ritlges. changes in vehicles and road I)uiltling equip-

ntciit. t ~ e ~ ~ ~ ~ J ~ ~ l i l ~ l i t : \ ~ roads serviiig cuuiitry arcas and safety furnidiings : I n i 1 ~ Y I I - I < < 011 niaiii ro;tils ; cxainples of plaiit parts matiuiact~iretl at the I )epartnictit's C'entral \\'(lrkShO{J ; iiiaiiual ~ n t l rharts relating to tieltl service and repair of pI:tnt : ;t model ex1)I:iiniitg where over-

i1)k ( 1 1 1 i i i i t i i i roatls whew there is ;I ie ; a 1arg.c. m(idcl illtihtrating traHic

arrangeinetits at the southerr o l ~ ~ ) r ~ ~ a c l i to the Sydney Harliriur Pridgc ; aucl n road niap atid ;t <lisplap of the Jourtial, "hlain lioatlr."

The foIlo\viiig special ruatl etluip~iwiit was on csliibi- tion ;idjacent tu the marquee :-a travelling ivorkshop made at tlie I)eprt~ticit t 's (~'entral \\'orksliop ; :L cara- van of the type uset1 for housing plant operators in the field. also ~iianuiacturr~l I ) ? thc 1)epartitieiit ; and a line-marking macliine usetl for i i~arkii ig the ccntre-line on main roads.

Entrance to D.M.R. Exhibit

Transparent illuminated colour photos. of Main and Developmental Road Works.

I 8

Lentre line marking machine

Plant Parts manufactured at Department's Central Workshop. Granville.

June, 1952. MAIN ROADS. 125 -

Tenders Accepted. The following 'Tenders (esceeding Lr,ooo) were accepted b!. tlic Department during the months of

January, Febrnary and March, 195% :- -~ ~~ _ _ _ _ ~~ ,

Work I n Scrvice. I s a m e Tcndcrrr. of acceptrii .\mount. I Ilonil s o . ('i>uncil.

Boolooroo S . , Macintyre S . , Severn S., ... Tentrrfield S . , Tenterfield M.

~~ ~ ~~~ ~ -

f s. d. Constructiun (jf a steel and reinforced concrete briilgc

ovm the George's Rivcr a t Liverpool- Cnntract No, 1 .-Manufacture. supply and ilclivery Cleveland Bridge and 130,343 ,19 4

of motdlwork and machinery. (For rivctteii Enginccring Co. Ltd., Sterling. splices.) Darlington, England.

abutments. Australian.

completion.

do .... 204.739 I? 3 Contract No. 2.-Construction of concrete piers ant1

Contract No. 3.-Construction, crcction and final <IO do ... I17.210 I 2 L

do

Surfacing and resurfacing work on State Ilighways, Coiiatrucliciii Scrviccs l'ty. 20.064 T 8 1 0 . 5 1 - 5 L . Ltd.. Dubbo.

Arrial photography along Trunk Road No. 61 between Brown and Dureau I-td.. 2,419 o 0

Parkes and Condiibolin and State Highways SOS. 9 Melbourne. I and I O i n the Sewcastle 1)ir;trict and an area in the Manning River District,

The following Tenders (exceeding f~ ,ooo) were accepted by thc respectivc Councils during the months of January, February and March, 1952 :-

I Road No Cnuncil.

I Bland S . ... 6

Burrangong S. ._. 78

Byrou S. ... I O

Coolamon S . _._ 24.3 Demondrille S . . . . 78 Deniliquin 11. ... 20

Dorrigo S . ... 1 5 1

Harwood S., .., i o IIaclc~an S .

Illabo S. ' ' ' 1 57 1 2431

... Jcrildrrir S. '7

h ~ a r t ~ i a g u y S . ... ! 2 0 2 1

JIrrriwa S . ... I . . .

Mitchell s. . . . I 5'1

33.3 j

no ... 59

Work. I 'Cen(lcrcr. i

Amount.

Supply, delivery, spreading and rolling 4,000 cu. yds. F. A. Lewington . , . _ _ . gravel. hverage lead y m.

Surfacing . . . . . . . . . . . . . . . . . . . . . B.H.P. By-Products Pty. 1,td.

Supply, heating and spraying of bitumen __. do do

Supply and delivcrv of h a m hrtwren I m.

... . . . . . . . . . . . . . . .

do do

Surfacing 13 m. 2,400 ft. t o 16 in. 2,400 ft. Surfacing

...... Supply and rlrlivery 2 . 2 6 5 cu. yds. gravcl to stockpiles./ (Isenford's Pty. J.td. ...

.\vcrage lcrigth of haul, X I m . Supply and delivery 4.392 cu. yds. gravel. Average 1'. .\. L)elancy . . . . . .

Construction of cartliworks hetwem 3 m. 4,765 ft. and I,. D. Swcrney . . . . . . 4 ni. i .mo ft. and between 5 m. 2,600 ft. and 5 m. 3.750 ft.

I'liish hitumcn seal 12.75 in. to 15.75 m . . . . . . . B.1I.T'. I(y-Products I'ty.

lead 54 m.

I.td. Flush bitumen seal I 7.1 5 m. to 20.15 m. . . . . . . du cl0 ... Supply, delivery and spreading of X , I m cu. yrls. gravrl. J . Bruton . . . . . . ... Supply, drlivery and spreading 5 , I I O cu. yds. gravel. do ... . . . ...

.\vcragc lead, 3$ m. ~~

.\vcragr l p a d 3 : ni.

lnam a t various locatirins.

roadh.

...

. . .

Supply, dclivcry- and spreading zj. l .%o cu. yds. of sandy G. G. Gillham

Supply, delivery and spreading gravel on various main Clifford Urns. Leneth of haul variahle between d . 5 in. and

Average haul I ) m.

~" ih .5 m.

. . . . . . ... Rcpairs t o Bullenbong Creek Bridge J. T. Hranry . . . . . . Surfacing 15.8 m. to 19.4 m. . . . . . . . . . _. . B.H.P. By-products I'ty.

1,td

6 s. d. 2,000 0 0

2.136 16 6

1,661 o 11

2,370 7 3 2,363 6 8 3,696 9 9

2.837 17 7

4,800 19 n

1.53s .I o

1,228 2 6

',o..jj o 2

2,061 17 2 2,651 13 8

1.533 0 0

6,916 .j o

8 , 3 1 0 1 2 o

1,760 I O o 2,766 18 3

I28 MAIN ROADS. Vol. XVII, No. 4.

! Koad No. Council.

I'crlS ...

Do ... ... T I

Sutherland S . . . . I 2 2 ;

I

I Construction of I<.('. 13ridgv 140 It. long over Tangaratta1 b'raser Bros. Indwtrirh I'ty. Creek. l Ltd.

Construction of R.C. Bridge Xr f t . long over Timbumburi do I l l ) ... Creek.

X O / I O O bitumen. Pty. I.td. Supply, heating, fluxing and spraying r q . 1 0 0 gala. ofi IV. I3 Carr Construction/

Tumbarumba S . X g Supply and delivery 3,788 cu. yds. gravel . . . . . . Klioberg and Barber ... Do . . . I 2 8 2 ) Supply and delivcry 673 cu. yds. aggregate .. . . . . ~ G. C. Ashcroft ... . . . ~

U'ade S . 80 Surfacing . . . . . . . . . . . . . . . . . . R.H.I'. Iiy-Prodncts P L ~ . /

2x4 . . . I 1 .15r

321

Urana S . Construction o f hridge over Billabong Crcck at liand . . . I E. J . \Vhitty . . . . . .

. . . . . . . . . . . . . . . . . . . . . cl<) (10 ... Woodburn S . Supply and application of prinring tar and bitumen do do ...

SYDNEY HARBOUR BRIDGE ACCOUNT.

Income and Expenditure for the period 1st July, 1951, to 31st March, 1952.

Inconic. .L ...................................................... Road Tolls 434,111

Contributions - Railway Passengers .................................... S1 ,583 Tramway and Omnibus I'ashcn~ers ............... 20.720

Rent from Properties ....................................... ro,zg9 Miscellancous 57 ...................................................

~ ~. __ 1546.780

~ ... ........

lixpendil!rw Cost of collccting road tolls ...... Provision for traffic facilities ..................... Maintenancr and minor improvcmt~ts . . . . . . . . . .4lterations to archu'avs ...........................

. . . .

....

. , . .

Amount

I I ',,,<I I i 0

2 ,188 i o I O

i ..... 37,505 ..... 4,834 . . . . . 4O,lCJ7 . . . . . 1 IC1 . . . .

.Administrative Espcnscs _. .. I . X J ' I.oan Ch;irgch--

Interest ....................................... IC,S,U io lixchn nzc ....................... 15,075 Sinking Fund .. . . . . . i').X75

L . { I , W O Miscellaneous . ........................... 1.247

4326,635

MAIN ROADS STANDARDS. NOTE: Numbers prefixed by U A '' are drawings, the remainder are specifications unless otherwise noted.

Form No. 402 Instructions for Design of Rural Intersections (acceleration and

deceleration lanes). (March, 1951.)

KERBS, GUTTERS, AND GULLY PITS. Integral Concrete Kerb and Gutter and Vehicle and Dish Crossing, (Revised, July, 1939) and Drawing.

Gully Pit (Revised, May, 1939) and Drawings (a) with grating (A 1042); ( b ) Kerb inlet only (A 1043); (c) with grating and extended kerh inlet (A 1352); (d) extended kerb inlet (A 1353).

A 190 Gully Grating. (1933,)

243

245 (Ar34A.)

Form No. EARTHWORKS AND FORMATION.

70 Formation. (Revised, June, 1949.1 A 1532 Standard Typical Cross-sections. A 1149 Flat Country Cross-section, Type A. (Revised, 1930.) A 1150 Flat Country Cross-section, Type B. (Revised, 1936.) .4 1151 Flat Country Cross-section, Type DI. (Revised, 1936.) A 1152 Flat Country Cross-section, Type Dz. (Revised, 1930.) A 1476 Flat Country Cross-section, Type Er. (Revised, 1937.) A 1101 Typical Cross-section One-way Feeder Road. (1936.) A 1102 Typical Cross-section Two-way Feeder Road. (1931.) A 114 Rubble Retaining Wall. (1941.)

PAVEMENTS. 71 Gravel Pavement. (Revised, June, 1949.) 228 Reconstruction with Gravel of Existing Pavements. (Revised,

254 Supply and Delivery of Gravel. (Revised, Augost, 1939.) January, 1939.)

72 Broken Stone Base Course. (Reprinted with amendments, August,

68 Reconstruction with Broken Stone of Existing Pavement to form a 1947.)

Base Course. (Revised, October, 1933.) 296 Tar. (Revised, May, 1949.) 337 Bitumen, (Revised, February, 1939.) 305 Bitumen Emulsion. (Revised, September, 1942.) 351 Supply and Delivery of Aggregate. (Revised, July, 1941.)

301 122 Surfacing with Tar. (Revised, January, 1949,) I45 Surfacing with Bitnmen. (Revised, January, 1949.) 93 Re-surfacing with Tar. (Revised, Jannary, 1949.) 94 Re-surfacing with Bitumen. (Revised, January, 1949.)

65 Waterbonnd Macadam Surface Course. (July, 1939.) Supply and Application of Tar and/or Bitumen, (Revised, June, 1950.)

230 Tar or Bitumen Penetration Macadam, Surface Course, 2 inches thick.

66 Tar or Bitumen Penetration Macadam, Surface Conrse, inches thick.

125 Cement Concrete Pavement (April, 1939) and Plan and Cross-section

466 Bituminous Flnsb Seal- and Reseals-Fluxing of Binders. (January,

GENERAL.

(Revised, December, 1936.)

(Revise,, September, 1936.)

A 1147 (March, 1932.)

1949.)

342 Cover Sheet for Specifications, Council Contract. (Revised, Jan., 1948.) (Revised, Sov., 2 4 ~ General Conditions of Contract, Coiincil Contract.

64 Schedule of Quantities. 39 Bulk Sum Tender Form, Council Contract. (Revised, Augnst, 1946.) 38 Bulk Sum Contract Form, Council Contract.

121 Provision for Traffic (Revised, June, 1947) with general arrangement, (Revised, Tanuarv,

1951.)

.4 1323 and details A 1325 of temporarv signs. 1947.)

A 1342 Warning Signs, Details of Constriiction. A 1346 Iron Trestles for Road Barriers. A 1341 Timber Trestle an4 Barrier. A 1824 Light Broom Drag. (1941.) .4 1924 Pipe Frame Drag. .4 178 Mould for Concrete Test Cylinder. A 1381-3 A 1452-5)

A 478

Tree gaurds, Types A, B, C, D, E, F, and (;.

197 Hire of Council's Plant. (Revised, April, 1937.) Specimen Drawings, Rural Road Design, with drawings .S4784 and

L -0-

.4 141R Concrete Converter. (1936.)

FENCING. 14% Split Post and Rail Fencing and Drawing (A 43). 141 Post and Wire Fencing (Revised, December, 1947) and Drawings (a)

143 Ordnance Fencing (Revised, February 1934) and Drawing A 7.

144 246 Location of Protection Fencing (instrnction). (Revised, May, 1940.)

Plain (A 494); (b) Rabbit-proof (A 498); (c) Flood gate (A 316).

(Revised, November, 1939.) Chain N'ire Protection Fencing and Drawing (A 149).

A 1301 Motor Traffic By-pass g feet wide. (1936.) A 1875 Motor Traffic Bypass 20 feet wide. (1942.)

A 4 I8 84

A 26 371

A 421

.4 44 A 2995

25

A t A l+Z

138

206

A 1832 A 309

W O

A 1886

A 45

BRIDGES AND CULVERTS. Standard Bridge Loading (general instruction). Data for Bridge Design. Data accompanying Bridge or Culvert Designs. Waterway Diagram. (Revised, 1943.) Waterway Calculations. (1939.) Boring Gear, 2 inches. (1930.) Boring Gear, 31 inches. (1949.) Rod Sounding Apparatw, with tripod (1947). Pipe Culverts and Headwalls (Revised, December, 1939) and drawings, Single Rows of Pipes, 15 in. to 21 in. dia. (A 143, Revised, 1951) 2-3 ft. dia. (A 1391, 3 ft. 6 in. dia (A 172), 4 ft. dia. (A I?$), 4 ft. 6 in: dia. (A r74), 5 ft. dia. (A 175) 6 ft. dia. (A 177); Double Rows of Pipes, 15 in. to 21 in. dia. (A 211) 2-3 ft dia. (A 203), 3 ft. 6 in. dia. (A ZI j, Revised 1951) 4 ft. dia. (A 208), 4 ft. 6 in. dia. (A 207) j ft.dia. (A 208, Reviked ,19511, 6 ft. dia. (A 213); Treble Rows of Pipes, 15 in. to 2 1 in. dia. (A 2x0, Revised, 1951), 2-3 ft. dia. (A 216) and Straight Head*alls for Pipe Culverts, 15-24 in. dia. (A 1153).

(.1948.) (Revised, November, rq48.)

- . Joint for Concrete Pipes. Inlet Sump Pipe Culverts for 3 ft. dia. or less. (Revised, Dec., 1947.) Pre-Cast Concrete Box Cnlvert (Revised, February 1948) and drawings 9 in. high (A485), 12 in. (A446), I ft. k in. (A447!, 2 ft. (A 448), z ft. 6 in. (A 449).

Reinforced Concrete Culvert (Revised, February, 19qR) and instrnction sheets (A 305, A 359, A 306, A 304).

Cast-in-Place Concrete Pipe Culverts. (1942.) Concrete Cnlvert Posts. Pile Drivers, specification for 25 ft., and drawings for 50 ft. (A 209 40 ft. (A 253), and 25 ft. portable (A 1148).

.lrrangement of Bolting Planks for various widths of deck (Revised, September, 1948.)

Timber Bridge, Standard Details.

(Revised, Augnst, 1933.)

(Revised, June, 1937.)

(Revised, May, 1949.) -

(9,) iction sheets, ft. (A 1761).

1 sheets for ) Single Span ft. between

ft. 6 in. high to 8 ft. high,

ed, October,

:onstruction.

to Councils.

c -_ 7 I

State Highway SystJem of the

St,at,e of' New South Wales

3 State Highways ,-,

Divisional Boundaries __"__ ---_ Divislorml Offices __ 0 Area of New South Wales, 309,433 square miles. Length of public roads within New South Wales, 126,272 miles.

MILEAGE OF ROADS . -- CLASSIFIED UNDER THE MAIN ROADS SCALE OF MILES -~

A'I, AS AT 1st JULY, 1951. State Highways ........................ ................................. 6,533 Trunk Roads ..................... .......................................... 4,089

Roads ................................................... 2,859

Main Roads ............................................................... 12,698 59 ............... Secondary k ~ ~ d s (County of Cumberland only)

26,238

2,705 UNCLASSlFlED ROADS, in Western part of State, coming

within the provisions of the Main Roads Act ............

TOTAL .................. 28,943

..