News of the Month.

Metropolitan District. macadam surface course. Similar work has also been carried out hy Warringah Shire Council in Co'ndamine- The following Iwidges have bccn given minor re- street (hfail, ~~~d N~,r63). pairs antl painted recently :--Victoria , Penrith [Great \Vestern Highway). Fig Tree Bridge (, Hunter's Hill), and (Mos- Western District. man-Manly). A new two-span reinforced concrete bridge, 70 feet ~~~)~i~~ar~ill progress to t~lelIridgc Over E~~~~~~~long, over Cootnl)iiig Creek, on the Mid- Western High- is creek, oll (;reat \qrestern liiglllvay ill B~~~I<~~~~,~way in Lyndhurst Shire, heing huilt by thc Dcpart- Shire. This bridge was formerly only 16 feet widc ment by day labour. between kerbs, but. concurrently with re-decking, it is llcing widened to 24 feet. Ncpean Shire Council has receiitly tar-surfaced t!ie I'enrith-Mulgoa road (No. 155) for one mile, com- mencing just south of the l'enrith municipal boun- dary. Castlereagh Municipal Couricil has treated similarly one niilc of the same road between 7 miles and 8 miles north of Penrith. antl is preparing for further work of the samc kind. Vaucluse Municipal Council is re-shaping Bay-street, Watson's Day (Main Road No. 173). This has been made possible by the construction by the Council of 3. :: ft. 6 in. diameter colicretc pipe drain under the southerti sidc of the street. with consequent relief to tlie surface drainage arrangements. 'The pavement in Kurraba-road. Neutral Bay (Secon- dary liod No. ~OI()),south cf Ben Boyd road, has Penetrating with tar on the Bathurst-Oberon road been straightetietl by North Municipal Couti- (No. 256) at Kelso, in Turon Shire. cil to eliminate RII awkward liend. 'lhe re-surfacing of In Canobolas Shire, the Council is constructing a the rcmainder of the roadway will shortly he under- mixed-in-place tar macadam pavcmcnt on the North- taken. Western Highway east of Orange. The existing The uneven contour of two short section.; of Kings- macadam has been reconstructed to form a base for way (Main Road KO. 227) in the Shire of Sutherland the full length of the iicw work, I mile 3.176 feet, atid has been improved by adding a mixed-in-place tar the surface course has been completctl for 4.300 feet 'SI3940 146 MAIN ROADS. Vol. 111, No. IO.

~~ ~

l'lie district bridge gang is now reliairixg the bridge Contractors Farley aiitl Ixwers are maliing good over tlic 1,aclilan River at Condobolin, on the \Vyalong- ijrogress with the construction of tiic (leviation at C'otitlol~oliii-~l'r;ingietrllllli I-II:L

Southern District. A L)epartmental bridge gang has recently coinpletctl minor rcpairs to ;~nd p:iintetl the i)ritl:.e over the Shoalhaven River at \\!ami. 011 the ~uennlie~aii-Krai~l- wood trunk ro:itl (So. 51) 9 miles iiortli-west of l3raidwood. The gang is now engaged upon similnr kl.iin+cnancc patrol grarlcr on thc Mid-Wcstern 1 lighway in woi-k at the bridge wer thc I\Iongarlowe Ri\.er a: Lyndhurst Shire. Charleyoiig, on tlie Braitl\yootl-Ncrriga road (No 26jj replace a woril-out timlicr bt-itlge. 'l'hc Cou!lcil Ius received tenders for :i timber britlgc. Sz [cct long, over Laman's Creek. ni: the saiiie road near Stroud. I. I his I)ritlgc will replace ;iii old timl)er structurc which has rcachctl the cntl of its useful lifc. The total wor!c to Iic (lone will inclutlc i:nliroving thc ;ilig:umcnt of thc ap~'r0:l'hcS. C'ontr;ictoi-s 1:ryaiit and I3uchaiiaii arc engaged in t:rr re-zurf;iciiig 011 the (;reat Knrthcrn Highway be- t\vcen l I~~xh;llnan!l 'l'ar1-0. ;Z I)ep:irtnieiital hritlgc gang has completed repairs to the bridge over the I Iiunter Iciver at .Ilorpcth. and is at preseut eiigagctl upoii repairs to the timber bridge over thc eii!r;iiice to r.akc h~l:irqn;tric, oii the Pacific I I ighway at Swaiisea. North-Western District. The Ikpartment is liuiltling liy (lay labour 2 iicw Repairingi the bridge over the Murrurnbidce'. I

Expenditure from 1st July, "31, tu list March. ,932.

COUNTYOF CLIM~ERIANI) MATNROADS Fwn- s. d. C,onstruction of Roarls am1 Hriiigcs ...... I J2.873 IO Io Cost o! Land I

~~ Totals ... 393.87.t 18 0 - COUNTRY IfAIX l

~. ~ ~ ~~~ Tc.tals ...... 66l,oqo 11 o FEDERALAm ROAD$FUND- Construction of Roads and Uridgcs. including Resumptions ... 116.ro71~8 Miscel!aneous ...... 304 2__ 5 Totals ...... II~,.+IIIj I 9.822 ij 6 126,234 IO 7

-. - ~~ DEVELOPMENTALROA~S ~'UND- Conslruction uf Roads and Ridges ...... 29,209 .+ 0 hXj I1 7 29.896 15 7 Survey. Design, Supervision, and Administration ...... 1.980 IO 8 80 J L r.060 ij in Miscellaneous ...... 123 12 o - 27 0 7 150 IL 7 Tota!s ...... SUMMARY,"ILL FUNDS- Construction of I?oails ancl Bridgcs, including Resumptions ... 276,615 13 7 18,839 6 11 Maintenancc of Iloails and ...... 616.gb5 o h 40,138 8 I Repayment of Lo;:ns ...... 192.592 14 9 +,qo8 IO 1 Survey, Design, Supervision, and Administration ...... _.. 103,666 16 o 8.629 9 3 Miscellaneous ...... 12.8jO 5 I1 219 3 2 ... - GRlND TOTAL ...... , 1,zoz,690 IO 9 71.734 17 6 I I I I48 MAIN ROADS. Vol. 111, No. IO. Use of Premixed Macadam for Maintenance in the Metropolitan District. BY S. M. BROWN,C.E., E7ZgiVl.W. N li of the characteristics of noii-rigitl paveinetits hut there was a hmit to the delitli of cL::ting 1mctic:hlc. 0 is that, with increasing age. tlic surface contour ( To eliininatc the iiiorc 1iroiiouiic(:d ritlgcs and high teiids to Iiccomc uiieveii. l'his phenomenon spots, it would have been necessary to cut completely iiiaiiifcsts itself either as relatively short corrugations through the road crnst :it these poiuts. exposing, iii (due to inst;iliility of the paving material itself) or some instances, material unsuited for the surface treat- longer undulations (due to unequal subgratle resist- ment to follow. In any caw, such decli cutting \voultl ance). ,411 uneven surface impairs the riding qualities have weakened the old pavement and destroyed its of the road. I)ut the most serious aspect of the matter, utiiformity of consolidation antl burfacc character.) from the point of view of a road authority, is that the (hi account of the restricted aiiioutit of planing prac-- slioclts which cauw tlisconifort to travellers increase the ticable, sprayed m:iterial iiaturally gravitated into the duty of tlie pavement. The forces of destruction in- depressions, which interfcretl with the ol)taining of a crease in cuinulativc fashion by virtue of the impact smooth-riding surface trc:rtniciit. 1rrtgul:lritit.s not rticct upon surface irregularities. When the original eliminated by planing were therefore lilletl by liantl wen contour nf a non-rigid tar or bituminous pave- with hot, preiiiixeil macadaiii. This \V;IS tiece ment Iias definitely been lost, complete disintegration slo\v and expensive, although effective otherwis is only a matter of time. Tlir 'nest advance was to discard patching in favour The Problem.-Many of the main roads in the county of a thin, continuous carpet of premisctl iii:tcatlani. of Cutiibcrlantl were reconstructed with cion-rigid (;reater quantities of mixture were reqiiirctl. but the 1)lack-top pavements in the few years prior to the continuous sheeting dit1 licit require the sprayed surface incel)tion of the Main Roads Hoard and, after a period treatment otherwise necessary. The metlwtl of con- of service of seven years and upwards. during which structing the inacatlam carpet was :is follows :-Aftcr they were all careftilly maintained. cxhilri:ed seriously the road had been planed and swept. the hot mixture iineveii surfaces. The preservation of these roads has was tipped from lorries into Iieaps, wlicnce it \vas I)ecnme a major problem during the last three year';. distributed by barrows. .and then raked to a utiifuriii In general, a subgra(le of uniform supporting power tliickness Iiy hand. After cooling sufliciently. the mis- Iiad been developed by traftic, the pressing need bciiig ture was rolled with a 10-12 ton three-mbccl rollcr, for a smooth-riding surface. Kiding qualities could rolling being continued at suitalile intervais until coni l)c restored by scarifying and reshaping the cxisting plete consolidation was ol)tainctl. surface course, Iiut tlie tliliiculty attending this lay iii that the re-consoli(lation of several iiiclies of material The constituents of the mixture \vert: 2s follox would almost certainly result in sufficient unevenness Coarse Mix. I 'cr c r11 t . of surface to initiate a new cycle of progressive loss of Broken stone, r: in. gaugc _...... _ 3.5 riding qualities atid eventual complete disintegration. ,, fill. ,, ...... I" Therefore. a solution was looked for in the tlirectioa Win. ,, ...... , 1.5 of :tdtling a thin, iicw wearing surface with a minimum Sand ...... _. ... .,. ... IO of rlisturlxtnce of the existing pavement. Bitomcn, 60-70, IO gals. 1''' tnn. Early Methods.--The Iirst method tried involved the Fine Mix. use of a heavy multiple disc scarifier, with the diycs ict l'er cent. Rrokrn cion?, t in. gniigr ...... ,._ SO close together, drawn Iiy a tractor. With this machine, &in. ,, ...... 40 the tops of all irregularities mere shaved off, and the Sand .._ ...... _. ... _.. IC) cuttings were reniovetl to tlie roadside by a light Hitnmrn. (x-jii. io;-io* gal-. pcr ton. grader, followed by a hrooni. (This process \vas The aggregates were proportioiirtl l)y volume, antl illustrated in the l'ourth ..\nnual Report qi the Ahill niixetl in thc hot-mix macatlani ljlant at the llepart- .Koads Hoard, 11. 22.) l'lieli the road was !:prayetl. ant1 covered with fine aggregate; in accortlance with the ment's Rosehill depot. The proportions ivcrc atljtistetl when necessary to cover the va:iatiotis in the gri' I'IngS normal surface treatment practice. Tater, :I heavy drag was built for usc in Icvelliiig the surface prior to spray--- of aggregates received from different sources. Tlic coarse was used I1 ing aiitl re-surfacing. This implement consisted of two mix wherever perinittctl by the (1ep1 l)l:tdes. set at ;lpproxi~nately45 degrees to the road, ill of carpet to be laid, in order to conle7. iiiasiiiiiiiii a rectangular timl)er framework approximately S it stability under traliic. wide antl 16 ft. long. Tlicx side-mciiiljcrs were steel- Continuous carpets. using Iioth hot and cold prc- shod, and controlled tlic cutting action of the I)ladcs. niixetl materials, have I)ecti in service for periotls i;p The drag coultl IK fitted with light scarifying tynes at to three years. antl have acliievc~tl. gi,iier:illy, thc rc- its forward end when required. :The results obtaincd stilts aimed at. Une feature of interest is that the with either of these machines were reasonably good, new surface has bonded satisfactorily to tlic 3ld, June, 1932. MAIN ROADS. 149

whether of tar or hitnnien, \i;ithout the light preliminary : After some eiperimenting, a combined hopper and .praying. or "tack" coat. often considered nvcessary in drag was built. . The mixture is tipped froni the lorrici such circumstances. : into the hopper, -and is spread by the drag, in one Recent Methods.-Further developments were directed operation, to the required level. Thc drag consists of towards two points. Firstly. hand methods of placing steel-shod, timber - runners? 12 in. high, 12 ft. long, the iiiixtnre were very costly. mid. despite thc greatest and IO ft. apart, securcly braced together, ciid carrying care aut1 skill. (lid not give the degree of evenness in a single steel spreading 1)lade. set near the centre r.f the contour of thc hnislictl work which was fclt to he the framework, at right a'ngles to the runners. This tlcsirable. Secontlly. ewii if tlie cxrpet was perfectly blatlc may be raised arid lowered as a whole. and tlie sniotrtli \r.lien placctl, its non-uniform thickness tmdcd .' actual shaping edge inay be cambered as tieccssary.

I, Old road heforr rcccnditioninc. undulations shown und-r a straight-edgc. 2. Inequaiitirr .how-n up hy means ot chalk lines, straight in plan. I. Side-strip. Hume Highway. Ashfield. three months after reconditioning. ahow- inp cflect of leaky hydrant and pipe-joint beyond. 4. Lower layer of drag-spread macadam ready for rolling. The high spots are left uncovered. 5. Example of completed reconditioning with drag-spread macadam. tu protlucc, ultimately, an uneven surface due to vary- (The latter provision was incorporated Ixcause the ing degrees of consolidation at different points. This older roads have cambers covering too wide a range to could he overcome by laying the carpet in two coats, permit of iniinediate st:mtIartIisatlon in the course of thus arriving at smoothness by t\vo sricccssive approxi- maintenance. The adjustable blade meets the condi- mations, but hand methods proved uiiequal to detecting tions, and enaliles sonic imprwetne'nt to be effected and corrccting any hut the more pronounced depres- without using an uiidue quantity of new matcrial.) At sions. Mechalktl means were therefore developed for the forward end of tlic drag, there is a steel-lined distrihuting the misture, eventually rendering possible wooden hopper extentling for thc full width of the a high degree of economy in addition to securing the drag. 'The hopper may be mounted at either end. as desired accuracy of surface. desired, making thc drag reversible in action. The I50 MAIN ROADS. Vol. 111. No. IO.

drag is guided, within limits. by a long ;:rm attache11 necessity to stq) tlic rlclivcry of t1iateri:il in sufticiciat to the top of one of tlie ruutierc. In this way a straight time to allow the last load to I)c sprexl ancl complrtely edge to the surfacing can he o1,t;iinetl without recourse consolitlatcrl beforc the entl of the tlay. \\‘hen usiiig to edge-strips or similar devices. tlie drag, the latter portion of each (lay is :dlotted t.) In operation, the drag is attaclirtl to a loatlcd lorry tlie lower layer. wliirli iieetl not inimrt1i;itcly ljc COLI- by incaiis of chains with smp Iiooks. 'l'lie body of the solidated so thoroughly as is necessarv for the upper lorry is then raiscd stithcieiitly to start die mixturc layer. Spreading ciui tlitir Ije contiiiuerl practically runniiig under tlie tail-l)o:Irtl, tlic rate of discharge to the entl of tlie tlay. being controller1 by a rope attached to the liody aut1 IVitIi tlie drag. the surfacing is placed in two layers. running arountl the tail-hoard. Tlie lorry is thcn driveti The lower layer. avcraziiig $$-inch tliick. is applid forward at a malliitrg pace until it iq empty. 12 5-pi over a suit:ible length and thoroughly rolled with a lorry is tlischargetl nornially iii six minutes. iiiclutlil~g 10-12 toti three-wheel roller. Trailic ii ciiL.ouraqetl IU the time occupictl in attaclikrg antl tletacliitig the drag, ruii over the new work for as long as practicable antl but miser capacitics have $0 far liniitctl the out1)ut 1111 assist to coiisolir1:itc it immcrliately tire prelimiiiary tlic majority of works to from So to itx) tons per tlay. rolling is complete. The 101ver layer is tlius t1iorougli:)i Recently. on the !'rincc's I ligliwy :it Suthtrlantl, compacted atid sct up IicfoI-c tlie wciriirg surface is

I! I!

where the outpit from two mixers was :ivailable. 3-30 applietl. which ret1ucc.s io tlic minimum any tciitlciicy tolls of material were spread tlirmigli otic drag in ;lli for the formatioli of irregul:1ritics of .~rf:~rc,cotitour ortlimry working day. due to uneqwl coiisolitl:.tlon. The upl~erlayer is lait1 r.1lie crew requirerl consists of six men. esclutlin:g to an average tliidincss of 'i-inch. mil i< thoroughly the ganger atid the drivers of thr roller an:l the lorries. consolirlstetl by the roller. Tlie \vorli is tini4ietl. after Of tliesc sis. two guide tlie drag (one operating thr: the final rolling. by tlustitq the surf:ice wit11 CI-LISIICI- arm mentioned al)ove. antl tlie other guiding the lorry- dust (material sinaller than :P-inclr gauge J at n rat: oi driver'). twu regulate the flow of mnterial from the 2-.3 11). per square yartl. which is ii-tirlted into XI>)- lorry 1iy controlling the tail-gate opening. and the re- surface voids 1)y tlie traliic. .\ very clo:t. nwi-skicl maining two see that the mixture is evctlly tlistrihute(1 :xrface texture re.solts. aloiig the blade of tlie drag. 111 between loatls. tlie men Materials (Hot Mixing).--l'lie greaivr ;mi-( of thc :ittend to any iniiior bleniishes in the spread m-ttcri:;l inaterial used so far has 1)ecii niisctl Iiot at tlic ccntr;il nut1 attend to tlie slioultlers. Evctitiiall\~.it is Iiopetl to (lepot at liosrhill. Iiut Iiot inixers :ire w\v iii,txllr(l :LI reduce tlie nunibcr oi men required. but so far, thc sulisitliary depots. :ciitl the output r~f~vc~-al couiicils' differences in the tlimensions and rear-cntl arrange- nlants may l)e utilised wlicir required. Tu thi> \ray tlic ments of the hired lorrim haw militated agaitict tliic. needs of the county of C"~uml)erlantlIia\.c !it:en :de- 'The crew required for 1i:intl sprcatling contained quately covered. nine cstra men. aiid the average tlaily output was only The mixtures used for spreading ;villi a drag arc .Go tons. Tlie main reason for the low output \vas the generally similar to. and liavr beeti developed froni, June, 1932 MAIN ROADS. 151 those used for the earlicr liaud-spread work. A fine mix Ground Cuban a5plialt was added I at the rate ,. of ( i.e.. @ iiiaxiinum size) gives the hest scrface tinish. 2% Ib. per gallon of binder) during tlie actual mixitig Sand IS geiierally omitted from the I~.imcr laycr mix- to increase the tenacity of the binder. The work ture iii order to give the maximum bond with the carried out with this binder has exhibited a tendency csisting work and ( Iry reason of the rougher surface I to disintegrate during cold weather. particularly wlieii \\it11 the wearing course. To incrcxc the ease of the aggregate has comprised. priricipally, crushed matiipulation. or workability. required for dragging, quartzite and Imrphyry gravel. Worts :we king greater lrroportion of fines is required thm for hanti- matie to trace this difficulty to its source, and to spread material. cliniinate it. l\t present it is hoped to ohtain .batter In keeping with the general policy of preference to Yesults lly utilising a softer grade of pitch. local materials, oiily a very limited quaitity of bitumen Bitumens fluxed with light oils, conforming broadly Iiintler has been used in tlrag:-s!ireatl wirk "Duraten;l.s" to the characteristics of Sj/sO liquid bitumen. have alco -a mixture of gas-tar pitcli. and lri:uiiicn--lix been been used. At tlic Iirrscnt time. eilorts arc being made the Iiintler used fur the Iiulk of tlie work. It consists to adapt local tars to coltl-mixing by conilriiiing with of fm per cent. of Ioo-pen. bitunien aiitl 40 per cent. of thein a percentage of parallin-base road oil. gas-tar pitch of GO penetration. This tnisture has a Results.-The succcss of tlie work described above jxnetration of 180. i.c.. it is softer than eithe:. of its inay bc tested definitely. up :o date. in two ways--by constituents. The principal cliaract(vistics of Dura- examining the riding qualities of the completed sur- :enax are as follows:- faces. anti by comparing cost data. Later. w1ie:i Soltcniny pnir.t ... 1;. Ihctility (77" F.)... So cm. suflicient time has cl:ipsccd. the (lurabiiity of the work Float test (.5"-.jo" C.) ... jjo secs. ,, (Gg" F.\ ... 50 ,, carricd out more recently by drag-spreading will have Pr-c carhnn __. ... -?.- , prr ccn!. ,, (50" F.j ... I i .. .. f.30' I7.j ... 4 .. been estaldishetl, ant1 a conipletc survey ui the results will Ire p(idile. The rlctails of tllc surface layer mixture tiow used ( subject to slight adjustment to suit wriati$insof gauge Kitliiig qualitics are tested by means of the rougli- in cotniiierc-ial supplies) are as follows :- ometer. This tlcvice. dieti nttaclicd to the axle Per cent. of a car. will ailtl up the vertical iiioveiiienr9 of the axle hj weight. caused by ineqti;ilities of the road snrfacc. so that. ii I4roknn stmc. $in. gaiigc ...... 36 tlic saiiic car is tli-iiw at a coilstant speed ovcr various i",. in. ,, ...... -I 5 roads (the tyre pressures remaitling ro:~stant), tlie Sand ...... rq Ihrati-nau, ?;-io gdlrin-: pm ton. roughometer registration per mile for each road \vi11 be a measure of its e\enness. Tlie follnwitifi rea& The general ride is to use the c-oarsest mixture which inys wcrc taken at a speed of 30 miles prr hour:- can be placec! with tlic depth of siirfacc i-cquired, ~..c/., in super-elevatiiig cwves. or lrllililing up the edges Rouqhn- nrter Reg- of high cain1)erctl pavciiicnts, a mixture similar to that istration. given aliove for hand-spread cnarse ni/x is oftm uscd. ~ ~~ ~ - Tlie hot mixture is transported in niritor lorries of a miles. in. prr capacity suited to tlic length of haul (i.~.,for short mile. !iauls. c.fj.,2 miles. lorries of alrout 2 toiis capacity are Ihag-yh-cad fincad .6r 63 pi-efcrrerl. as making tlic joli inore near!y a conrinuous ani reronditioninq. To Cal,ramat?a Hanrl-sprcarl macall- .R: 166 process, ant1 for long hauls, c.q., IP miles. lorries of tnrmotf. am rccondi tinning. cp to j tons capacity are most siiitahlc? .is the larger At TTn:<'s l-?il! !?iturnen ~ siir!acc!il -zR 120 body of iiiaterial retains its hcat hettei-j. \Vhen the maradam, built prioi I hot material is covered with a 1)lanket liiil(!e h!; sowing to IO?.?. togcthtr ciiipty cement I)ags. it may Ire carried 1111 to 20 miles without sufi ig dctrimcntai loss of heat. I land-spread macad- 'q) '3.5 I?n Materials (Cold Mixing).--Material f.?r uqe nutside ;im reconditioning. ',I .18 J61 Ritum2n - sur(aced Y j 2 76 thc radius of action of a hot-mixing plant is prepretl macadam. hiiiltprloi liy mixing aggregate and hiutler cold in concrete to 192.5. mixers. The advantages of cold mixing are. firstly. Pavran~lln- Riclmom rond (A'c. 18.1). that a small. mobile plant can turii nut cheaply a sub- Vrom Jiinc:ion-road . 53 stantial volume of niiuture. and, seronrlly. tlic mixture 615 inay br stored for up to teii months without untler- Hnnt's Crcrk to Bar 124 cuing alrirrccialilc tlcterioration. The constituents of my-st.reet. From railw? c.roi.in: 31.5 the mistnre. except the binder. are identical with those (19 m.) tn !unction I28 for hot-mixed material. Two binders have been usecl- TDad. a t:ir-bittiinen mixture and 85/80 liquid Iliturncn. The compositiou of the tar-lrituinen mixture \vas as follows :~-- Surnniarising thesc figures. which are thoroughly Per cmt. representative. it appears that thr micveniiess of the Gas tar pitch !?c-?o pen.) ...... -0 new drag-spread surfaces ranges from 53 to 66 in. pcr Hravy tar oils ...... IO Flnxcd Trinida:! aqpha1C ...... 17 mile, the average Iieiiig hr in. per mile. The hand- Mexican bitumen 1100 per..! ...... 8 spread surfaces show a range of from 120 tu 166 in. 152 MAIN ROADS. Vol. 111, No. IO. per mile, with a’n average of 149 in. per mile. The j3.365 square pards, of wliicli 4j.617 square yards latter surfaces are, of course, a season older than the receivecl two layers of new material. 'lie details arc former, so that annual tests of the two types of surface as follows :- will ticetl to be undertaken for some years before a Materials. coml)letely fair comparison will be possible. The Doratexas, delivered in bulk to icixer ... 9:d. per gal. untreated surfaces, all of which arc ninrc than seven Broken stonr, in. and & in,, in stock piles, years old. show a roughness ranging from 276 to or miser hoppers ...... os. &I. per ton. in. per mile. the average Ixing in. per mile. Sand, in stock piles. or mixer hopper< ... 5s. 611. .. 430 362 Crusher dust, in stork piles at mixing dcpot 7s. &I. ,, ,\ strip of \rell-finishctl concrete pavement in good ortlcr gave :I registration of 124 in. !per mile. 1;. Plant Charges. seems clear, therefore. that the use of the drag has Hot mixing plant ...... & 105. pvr day. introduced a regularity of surface contom markedly Heating kettle. Soo-gal...... I1 U. .. superior to anything previously obtainable in recontli- Lorries, 5-ton ...... 10s. &I. to I IS. 6d. per hoix Drag and hopper spreader ...... IS. gd. per day. tioning work. antl superior even to that usually asso- Stcam roller, 10-12 ton ...... LI 5s. od. .. ciated with new high-class pavements. There can he no tlflLllJt that this estra smoothness is an extremely Costs per sq. yd. v:ilu;ible feature. ‘fhe rcsults. viewed from this aspest, Prcliminary planinji with heavy drag (two jobs only can Ire regartletl with much satisfaction. treated) ...... ~~Sd.-r~~~d. Lower layer (.{=,.017 sq. yds.), average thickness Costs.-The following tlctailP have heen compiled .3-.4 in., average for all jobs ‘34 in...... 625d. Rolling lowver laycr ...... 33d. from the cost records of work carried out from a field Upper layer (53,3h.; sq. yds.1, averase thickness mixing lhnt located on the Prince’s flighway near in,, average for nll jobs ‘72 in...... Is. 1.2jd. \\-aterfall. During September antl October of last Rolling npper layer ...... 3-ld. year. pni-tion ( ~h.;y)squarr yards) of the Lowcr Surfacc iil!ing (crusher dust). average I ton pcr goo sq. yds. !three jobs only treated) ... .2d. South Coast road (No. 1S.j). from the foot of Bald Miscellaneous ...... +;d. Hill to the T’rince’s Highway at the foot of Bulli Pass, was recontlitionetl, ant1 during October of the same Summary. ycar. portio’ii (7.524 square yards) of the Prince’s Total aret rccorirlition~~l ...... ~5.36~sq. yds. Highway hetween George’s River and Loftus was Total quantity of mixtnrc ...... 2,.tI? tons.. Length of haul ...... 5-9 miles. similarly treated. In each case. :he materials were Weightcd average length 01 h?nl ...... 7‘8 .. unloatletl atid fed to the iniser bv liand labour. ant1 Average total thickness of surfacing ...... 1.0 inch. tlie mixture was spread on the road. in a single layer, Average cost per sq. yd...... Is. Sri. by h:llld also. Average cost of mixture, consulidatcd ... 34‘. 3d. per ton. Costs per sq. yd. The cost (lata do not afford any comparison of value S. d. between hantl-spread and drag-sprearl work because Wcaring surface ...... I 9.8 the prime costs of the materials. the mean lead from Rolling wcaring siirlacr ...... 0 0.8 thc mixer to the job, and the mixing ctrntlitions are hliscellanepiis ...... o 0.3 entirely dissimilar for the two groups. One point.

Avcragc cost pcr 3qq.yd...... I ro.9 however, does emerge : i\ihereas the a5cr:ige tlriclincs. of the hand work (one course) is .8 inch. that of the machine work (two layers) is 1.0 inch. Tlirrc is. of Summary. course, a gaiiT in riding quality. antl an addition to the Total area rrcontlitioned ...... 24.31# sq. yds. thickness of the road crust, in the lattei- case tc: which quantity of mixture Tot;tl ...... 872 tons. considerable value can be assigned. lint it 15 evitlen: r\vcr;qc thicknrs.; of surfacing ...... 9in. that if the niixtnrc could be spread at least as thinly as I.rngtli of haul ...... 124-14 miler. in the former case. then the supcrioi-ity of the newer \Veighted avcragc lrngth of haul ._. ... 13miles. *nethod would be complete. It is hopd to achieve this Cost of hrokm stone at niiuer .._ ... 15s. d. per ton. as a result of developmental work at pcent in Cost of sand at mixer ...... 19s. IId. .. progress. Avcmgr cos? oi misturr, ennsoliilatrcl ... 5%. 6d. .. Trend of Future Developments.-Trials arc IJcing made The next tabulation is n summary of the cost data of a combination of a lower layer c,f lire-mixed for live jobs carried out durinK (.)ctober, November 1:iaterial laid through a drag and an upper layer huilt aiid 1)eceiiiher. 19-31. on roads within raiige of Rosehill lip by spraying antl covering with aggregate :is in a tlrpot. viz.. Hume IIighway, hctrvcen Parramatta-road normal surface treatment. 1t is Iiopxl to overcome in ( (;reat \\‘estern Highway) and Cross-roads ; State this way tlie tlraining of sj)rayctl biiit!rr into surface Highway KO. 13, between it? junction with tlie Hume depressions. i\s dragging is now an c~tablishcclpr:ic- Fligliway. north of Liverpool, and its junction with the tice in surface trcatnient. it is espectc;l tlint there will (ireat \\’catern H;gIiway at Parramatta ; antl the Se no loss of smoothness. as compared \\it11 t\vo-l:i) Parr:iiiiatta-\\’indsor road (KO. IS^) ne:ir McCrrath’s pre-mised work. while the smiller quantity of iiiaterials IIill. In each cabe, tlie misture was prepared at Kose- 1,ivolved will make for wry iiinch cheapcl- work. hill. where niechaiiical handliiig of the compone.it Cniicrctc pavctiieiits rcnderctl roiigli and uiicven by materials is pmsible. and was spread througl? a drag. heavy wear have been resurfaced successfully with a The jobs varied in size from 5,030 square yards io carpet of pre-misecl material ronstructrd as described 19.826 squarc yards, the total area reconclitioncd beiiig in this article, but on account of tlic difficulty of June, 1932. MAIN ROADS. 153

:horoughly cleaning the concrete it is usually necessary the identity of the body carrying it out. This informa- to make use of a preliminary priming or lack coat sf tion is due to the travellers using the road and who pay tar or bitumen. for its upkeep, and it very often prcvents inisunder- 'The method is also being used succesaftilly to restore standings and forestalls possible criticism. the riding qualities of liadly worn wnotl I)lock pave- The notice-boards used by the Depa.rtment of 'l'rans- ments. As in the case of concrete. a tack coat is founJ port arc illustrated in Fig. I. Those relating to road- ndvisa1)le. For- a lasting surface. it ;s ~~c:ccssarythat work comprise the following signs :- the pavement be perfectly tlrained, otherwise the arch- (i) Reconstruction Sign.-This gives notice of a road coni- iiig action due to swelling of the blocl;~ conseqi~ent pletely blocked to traffic for a period. It is of white characters upon absorption of moisture from bclow will disturb on a hlack ground, as this is the most conspicuous form of sign when illuminated l)y headlights at night. The arrow is the I)ontl with the surfacing. antl tli.;intryption will movahle, and may he changed to indicate a by-track either to occur, if nut before, when the blocks dry antl resume tlie left or to the right. or he removed entirely. The name of :heir normal position. the anthority givrn is either the Dzpartment or the particular Council, w-hichcvcr may lie in direct ciintrol of the work. -- (ii) Repair Sign.-This sign is used where men and/or plant are engagecl iipon a road during working hours but the Warning Signs on Repair Jobs. rodway is clcar and unohstructcd for the remainder of each day. There is 110 nee11 for white characterc upon a black ONEor two instancci have come under notice lately of ground, as the sign is not displayed at night. Black characters work being carried out on main roads iniilci- contlitiocs on a white ground. which arc tiinre conspicuous diiring the day, are therefore usiid. Thcre is the same provision as in the giviug less than the desirable amount of warning antl case of (i) for indicating the direction to be taken by traffic. guitlauce to travellers. and less than sufficient prot-c- (iii) Resurfacing Sign.-This is used to indicate the pres- tion to thr workmen engaged upon the rod 'l'ravel- ence [if wet tar or hitutnen upon a road. Spattering of these lers are entitled to due warning of ally co:idition of a materials tipon vehicles will occur if a newly rcsurfaccrl section

[WET TAR] DEPARTMENTOFCONSTRU~~ON TRANSPORT DEPARTMENT OF TRANSPORT I 1 (iii) (iv)

Fig. I. Road and bridge repair signa. Signs (i)-(viii) are 3 feet 6 inches wide by 2 feet 6 inches high. Sign (ix) is 3 feet 6 inches by IO inches. The characters are road or Iridge requiring black upon a white ground, or whits upon a black them to take another route ground, and are 7 inches, 5 inches. 3 inches, or 2 inches EYZRACK THIS WAY high, as required. They are incised similarily to the or reduce their speed, or standard direction sign boards. otherwise to exercise a de- gree of care not norrnallv is travelled over at other than a low speed, or before the work required at the particular iocality. as otherwise acci- i5 complctcd by the incorporatinn of the agxregate into the tlents or tlela\-s arc likely to occur. In addition, the surfacing. This is just as detrimental to the vchiclc as, it is to the success of the work on the road and timely warning is haply relations which should exist between the road thercfore imperative. Tar or bitumen spraying work is gener- authority atid travcllcrs generally are somctimes ally conhned to half the width of the liavement at a time, so impaired. that the necessity for indicatinp a by-track does not normally arise. As in the case of (ii). hlack letters upon a white The displa!4ng of suitable notice-bo:irils is the most ground are used. as the sign is needed only during daylight, convenient nicans of covcring tlie situation. The same (iv) Deviation Sign.-When portion of an existing road is means are effective in protectiug the workmen from heing replaced Iiy a new road, it is desirable to mark the ends possible injury by vehicles. as well as saving uiicom- of the deviation with this sign, which is of an explanatory plcted portions of the work from injury by premature rather than a warning natiire. The sign indicates the natiire of the works, the idcntity of the au~horitydirectly rcslionsihle. use by traffic. It is generally possible to give, in thc and presents an ohvious explanation of any shortcomings of trotices, some indication of the nature of the work and the section of existing road to be eliminated. I54 MAIN ROADS. Vol. 111, No. IO.

I.Ilie signs re1;iting to liridges arc as follows. All The signs slioivii (supplemented 114' iiie tisunl lights the shoultl have white Icttcl-s oti a Ihck ground. as .rnd barriers) arc bcing uscd oil the L)el)arttiietit's owti a11 may lie used :it night :- road aid 1iritIg.r. works. They :ire coti~iiietitletlto cntiri [v) Bridge Repair Detour Sign.--Rrikc rcliairs, unlcss of cils for usc on ivorks mitler their dircct control. It is a very slight c1iar:icter. iiicvitalily mean sonic temporary re- strictions in regard to the weights and speeds of vchicles prr- niissililc (luring the repair pcriiid, This sign gives tiinely ivarniiig tliat a hridgc is closed to traffic exceeding a certain weight, and indicates the route whirh wch vehicles should follow. It wiiuld lie placed in a cmspicuous position at thc apliropriatc rnad jnnctions. (vi) Bridge Repair Warning Sign.-This is the sign to he used close to r;ich end of :I Iirirlgc under repair. It inay lie dis- played intermittently or cnntinuously during mrorkii~ghours. or clill-ing the full t\venty-ioiir hnurs of each day. [t map or may not lie used iri conjuncti(ltl with (v). In the former ra.y the two simis. (vii) Bridge Repair Stop Sign.-lluring a rrpair joli. if thc liridgc is lint clost~lc8)mliletel~. it is necessary to stop traffic ciirnplctel~from timr to time, and :it all tirncs. owing to tym- Iionry partial clismantling. only limited loads moving at afely lie accunnnodated.' The Ilt!rl>ose of to limit the weight anrl spccrl I>[ vchicles riclp. and. scc~ndly,tu ciisnre that no tlic hridgc until pcrrnitted to do so l~ythc. ir pang (Iiy clay) aiitl the \v:itchman (by Fig. 2. Trestle lor supporting signs (i)-(viii) incluaive. is perhalls the most imlwrtaiit of those ticlr. Onl> I)? its nsc and riliscyvance in all cases where apiilicalrlc will prollcr protection lie gircn rlur- itnportant (hat thcy l)c displayed coiis~~icuiriisl~~,hit in iiig liriilgc rtyair~, l'his sign wiiukl Ire used instrxl 111 (vi 1 iieat a~id~iniform imiiticr. so tliat tl-avdlers will lvlien a g:rc;itcr dcgrre of rcstrictiiin tli:iil indicated by the :.c.cogiiisc them as ai1 atixilliary of the ~~cri~ia~ieiitstan- I;lttc,r is necessary in tlic iiitcrcsts of trafrir ainl the saiety and proxress oi the work. tlartl sign-posting systcm. :iiid rcqxct :iicm :iccordingly. (biii) Bridge Closed Sign.-This i, thc sigi aplilicablr when tratlic (Iver a lxiil::~. ii:h repaired or re-liuilt is con- Illctely hliickecl fcir a 1irri

ill accordnncc with the ..\wards made undcr tlic formation ; conscqucntly tlic outlet riiads---of which Industrial Arbitratiiin Act. 1012, and .4c1s ainenditig the ~Viiighaiii-Comboyiie~OsleyHighway main road same. and no claims whatsoevei- are outstanding against me in respecr 3f wages due anrl owing in ( No. T 12) is the chief--travcrie, in part, a greasy rctl rcsprrt of thc s:iid contract. clay which. unless surfaced, blocks traffic in wet (3) Insurance has Iieen effected Iry me in respect of all iveathcr. The grades of the road mentioned are steep i~iployersengaged on the said rnntrart in pursuance and the alignment tortuous. The pla'icau supports ex-- (if the Workers' Ciimpcnsation .2ct, 1926. as amended. tcnsive dairying. which is served by a butter factory and the insurauce nolicy therefor is still valid and snlisisting and covers my full liahility and the liahility at Comboyne. The Iiutter is transported by road to of the 1)epartmcnt of Trniinpnrt as a Prinripal. I',ringhani (thc rail hcatl of the district j, but, if thc main road is hlockcd for any time, t!ie factory tilust .\nd I make this solcnm declaration, conscientiously Iielievinz thc same to he true and in accordance with the provisions of cease taking cream, as it cannot store butter indefi- !hC Oaths Act. rpo. nitely. Sulrscrilictl and dcclarcrl the From \\inghani to within 5 ides of Coniboyne the clay Uf 11)s :it wain 1-oat1 is in the area of the Manning Shire Council, Iiefore me lnsticc of thPcacc. aid no difficulty is found by that h0d.y in maintaining it in a condition suitaMe ttr carry, in all weathers, the ST.\TT:TOH Y n IX'I ..\U .\TI i J S. !ioiited trafiic prevailing. although this section is. at its (Oafii.~:Ic!. IOM. -\-irifh .>'rhdirlr.) northerii end, snincwhat rough and rocky. rC.X Sllr'1 H \'v.\I.ES. 113 wit. Beyond llanllinc Shire. tlie road pasics into thc I of area of Hastings Shire. Of this 5 miles length. in tlic State of Ncw Sontli W;:iles [I!I l>ct-c,ljy sincr.rcly and !niles iniine~li;itclysouth of Conhoyne were constructed iii waterl~ountl of (I) I ani thc of the niacatlatn in espenditurc various t1.c (hitrxtors mentioned in the agrccrnciit datcrl L'om~iion\r~c~iltIi-ciiti~-S~ateand Fetlsral ;\id grant.< thr day oi during I 024-29. ancl arc in good older, while the One thousznd nine hundred and thirty mutherii half-mile has also I)eeii roughly constructd Iict n-ee n and the I)qiartmrnt of Transport of Srw Smith \Vales for anrl is reasoiial)ly serviceable. The i;iten:ciiing length of I mile tiirough clay country is bntlly graded anr! (2) A11 cmplovecs engaged hy the said Contractor and aligner1 and was unpaved. and it hati lwen holied to t~niplo>-erlill coiincctirrn \vith and on :?nd :rlront the reconstruct it and to cxtcnd the 1nac;idam pavement work of thc said contract have hcrn paid thcir wagcs in full in mnnrv, in accurd;incc with tliP Awards over it. However. iuntls did not permit of this. ant1 in:irIc midrr the Tnrliiatrial .4rliitrati-ecs engaged ini thi: >aid con- tr:ict in pnrhuancc (if til? \\'orkerz' Compensation Act. the plateau. il search for this nnterial in that location 1926, anri the insurance pdicv therefor is still valid orover1 successful. and during 1931 it ivas usetl to sur- ancl siilsisting and ciivers thc full liahility of thr f,.dce. at a cost of fr3fi. ilic worst portion. viz., 2,100 Colttractor and thc Iixliility of tbr !)cpartment ni fect of the I mile of road that had hitherto proved such TI-ansport iis a Principal.

(The information on road survey and design formerly con- used in coniiection tlierewitli as a y:ird. g:artlen. or tained in Main Roads Board Bulletitis Nos. I, 2 and 3. issd orchard, as serious delays may occur on accouiit of ail ill 1926, has lieen revised siirl is now combinvd in this article. which will henceforth supersrcle tlic Idletins mentioned. A- owner's powers untler the I'ublic Wor!.;s Act ( I()OZ\ to a t:ns tention is particularly directed to the refemices to articles, to object resumption. However. ilitliculty is amplifying some nl the aspects of the subject. which have overconit. if the owner signs a conscnl to tesuniption already appeared in ,.lfaiit Konds, and to any similar articles form (L.L.E. 186). appearing in suhscquent issues. A limited numhrr of coliirs 1,ound ;is ;I pocket-sire Imoklet for field refcrcncc will Iic prc- \\'hen locating a road tlirough priv;ite property. tlic pared and will he :iv:iihIile 011 application at n cost to Iic surveyor should obtain froin the o~vwror oceupicr a :iiiiiouncetl.--T;.[litor. i I'erniit to Enter for ('unstruction ( M.R. Form No. 2.3). Particulars should be taken of ;ill fcnces inter- Survey of Country Roads. wctetl. so that the I)ountlary fences cif tlir new road 1. The Purpose of the Survey.--:\. siiruey is made inay hc of types at least as good. Positions where gate.; bcfore the construction or reconstruction of a rod will be needed in the new fencing shnuid iic recortletl ; in order to obtain detailed information from which a *lie oiviicr's wislies in regml to these should be ascer- completc design tiray be prepared. Thc fdlowing sur- tained. \\'hrrc severancc will occur. ~hrqtiestiun of my data is necessary :-- acccss to water or provision of watcr suliply on thc (i) .4 plan of the cxisting or liropoacd roalaving esta!)lisl!ctl the of a curve Iiy increasing its racliuy iriay not lic ~i(issiI11c position of such points upon a map an idea of the withiiut rxcccding tlie maximum periiiissiiilc grade unless 1hc gradc of thc curvi'. in tlic first instance, is gradients liosshle between the various points may bc kept Irelow the maximum othcrwi~csatisfactory. gained. leading to the running of trial clinometer lines. (v) Side-cuttings sliaded from the sun rrften remain wet. 3. Interference with Private Property.-Viitlue or hciiig tlirrrforc costly to maintain. and slinulrl lie avoided if possilile. needless injury to. or interference with. private pro- (vi) The nature of the soil. c.:,,. suitability :is a snli-gr:i(le perty should be avoided in all survey work. Renson- or lialiility to scoiir, inclination nf tlie strata. aiid :hIc notice should be given to owncrs or occupiers of rlraiiiagc slionlrl hc studiccl in orilrr to xroicl a poor alienated lands bcforc entry for survey purpovs ant1 road found:ition or slipping or sctiiiriiip nf the eartli- works. fencing, stock, or other property should be protected tirins with existing roads should occur at tlir against tlamage. el. and reniote friiin ciirvvi on citlirr mad Freqiieiitly it is possible to avoid se\ crance. anti the corisequcnt compensation :iiitl costly procetlure neces- 5. Ruling Grades.--No ruling gr:irlc :.tce;)ru tlia:~ sary to estal)lish a deviation. by a relativcly sniall sacri- ; pcr cent. ( I in -.oj should I)c adopk,(l oil m;iin roads. !ice of locatioti or cost. Therefore a iiem route inter- Lut t~iisinay ~,e increasetl for short (listan fering with private 1:intl sliuultl always pos5t.s~sub- ilicated in Fig. I. In cases wlierc it i< iinlira ytantial atlvantagcs over any existing route. adhere to thcsc ~iiaximcni~grade.;. <'.!!.. on cxi

-~ ~~~ June, MAIN ROADS. 157 1932. -

Perfectly lcvel grades in cuttings should be avoided, size of drains and culverts, levels of inverts, and ~JIIacnmnt of the tlifliculty of draining 1he road efli- waterways to which each connects), and recomtncnded cientlp. Grxles flattcr than T per cent. (I in Iooj cizes and shapes of new culverts, otherwise it is im- slioultl I)e usctl only where the convexity and coinpact- possible for the dcsigner to arrange an adequatc system ntss of the road surface can be kept pcrfect. of culverts. An extentled cross-scctioti should be taken along the 6. Curves.--The maximuin radius a\dable should bed of each watercourse (to a distance of at lrast 300 be atloptctl always. with a minimum of 500 feet in flat fcet), showing the level antl the litnits of possible country and 300 feet in ordinary undulaling country. lowering of the surface level of any standing water In inountainous country a minimum of rgc feet should ant1 the bctl of the stream. The angle of skew between Ix aimed at. Sharp curves in gullir each watercourse (when in flood) and the road, and Lionalile than curves of the same ra whether the culvert should be built on the skew or sona1)le visibility is generally assurctl in the former square to the road, must Ijc recorded. Sonietiines a e. Thr inininium visibility (measured at a level dvert may be placed to advantage elsewhere than in j feet above the road surface) 011 straight roads thc watercoursr. 111 steep country, tiit length of ciil- with isolated curves in flat country should 1)c 500 fect. vert can often he reduced in this way. The minimum visibility on roads with many curves The class of country in each catchinelit area should should be 200 feet if carrying a sinall voluine of traffic be indicated, using the descriptions of Lht table below, antl 300 feet on heavy tral'lic routes. !n mountainous which shows the range of values for the run-off co- country these distances are often not practicable, hui efficient in tlie Talbot formula for calculating waterway Ijy benching the batters 011 the spurs reasonable visi- area :- Iiility can generally be lirovidetl. Flat country, sandy soil, cultivated land . , . , .35-.45 9 Gentle declivities, :il)sorhent ground Wooded slopes, compact stony grn Mountainous, rocky or non-absid - 8 Very steep ground. pa\reil streets .. 4 Probable values for the run-off co-efficient should be 47 given (using the table as a guide and bearing in mind that tlie common range of values is .50-.80), and the b value of the slopes should be indicated. 8. Final Location.-The preliminary traverse antl 51 cross-sections referred to in 4 above should he plotted 4 and revised on paper to get the best alignment con- I sistent with economical earthwork. In rough country revision is best accomplished by plotting the contours

3 of a strip on either sidc of the traverse line. * ru *1 m hfininium movement of earth, balancc between eii: L+A d &de Hvldredi 6- and fill, and desirabilily of down-hill haulage, are the Fig. 1. Diagram showing the variation of allowable maximum principal points to be watched when fiiially revising the grade with distance for main roads. location. 'rile super-position of horizontril and vertical The final line is then set out on the ground, pegged, curves should be avoitled as far as practicahlr, as this levelled. antl traversed. colidition increases the difficulty of coiltroliing vehicles. Survey of an Existing Ronte. ITl'here reverse curvcs occur. the .intervening tangent 9. Instruments.-" prismatic compass or, prefcr- shoL1ltl be long enough to acconimodete the standard ably, a theodolite niay be used. transitions, plus "5 feet, wherever possible.* Pairs of 10. Choice of Traverse Lines.-The traverse should, siiliilar c11rves joined by a short tangent arc o1)jection- AS far as practicable, and with due regard to improv- ;~ble; conq~o~iiidor triple-centre curves are preferahlc iii sucll cases. On bridge approaches, the nearest tan- irig the alignment, follow the centre of the existing pavement. TVhere the existing fortidon and pavc- points should at least the trandioti length, geat be plus iiient is val~~elcss,the traverse should follow the centre zj feet, from thc abutments. of the road reserve. Should these posi!ions he un- \Vlien laying out curves on a11 existing road reserve, suitable, a traverse line should be choseti, at the dis- it is generally convenient to drternline the maximum cretion of the surveyor, which will not only facilitate ubtainable secant distance, and then coinpute the corre- the survey, but will be suitable also for the sul~scquent slioiidiug radius of curvature. plotting, designing, and construction. All curves should be set out accurately on the ground, and detailed information regardiiig them pre- 11. Details of Existing Works.-The following in- served iii the ticld hook. formatioii should be shown clearly in the field book :- (i) Satnes of towus or villagcs passed tlirough. 7. Drainage.-It is essential to ascertain and mark (ii) Position of mile-posts, fences, walls and Iiuildings oil iipon a iiiap the boutitlarics of the catcliniciit areas rach si& of the road. draining across the road (obtained from existing mapi (iii) Railway lines and crussings, overhead hridges and 3r from compass atid chain traverses j. information re- subways, noting particularly the clearances of the latter strnctures. garding existing drainage facilities (c.r/., location antl (iv) Position nf IJO~CC carrying electricity or telephone ~~~ ~ ~ ~ ~~~~~ ~~~

f See article, " Conitructiun of Hurimntnl Curvri," Main Roads, Angnst, 1930. wires or cables. 158 MAIN ROADS. Vol. 111, No. IO. i ___ .. ~__-

i Y 1 \Vatu :itid gas iti:iin<. the cntl of die previous niile, e.(/., at CJ mile 200 feet a! (v!) tlydranis, st\vrr vents aiirl v:ilvc~ Iii,srs. :he peg \vou~t~;c;it~ o~.roo,ani at I iiiiie 5,000 fect ( YII 1 I'c,~itioiis of iiidividual utility structures alid liuildin~s idI.5ooo. Iieiiig staml)ctl in the direction of the pro- gressive chainage. I':acli tangent point pcg sl~oul(lhe

iliarkerl T.?. in addition to the cIiaina,rre. ;iiitl shod(! I !ia\re a peg, (11-ivcii OII the liatter towartls it, uii eitlicr atid large cnlvcrk apparmtly requiring reiiewal. as set out on tlie stail- 5ide. almut 9 inches aivay. I'egs at i:i1crscctio!i points rt1111 tlir niatcri;il.; used iii, un(l the wte of repair \\'here pegh a1-c not liliely to be tlisturld, eacli should of, siicli strricttire.;. (x) Iletails of liridges carrying gas :uid watcr mains. in- bc indicated Iiy ;I white 1i;iiiitetl intles peg. stunidin:: at cludina size oi niains and 1 Is (If strcam krl and 1c;ist TZ inclics ahivc the natural surface ant1 paintetl. watrr relativr to liriclgc. in Ihck character5 I,!< inches Iiigh. to correqiontl witli , (xi) L'ositimi, directioii ilf Ho\v durinx Ilrr&, al'd npprosi- the c1i;ir;ictrrs staiiil)etl ulmi the travvrse peg. (111 inatc flood diwliarjie of all crccks. :i-avelletl \v;iys tlic iiitlci lwgs should IJC $:et 111) on the I yii) Iktaily ai~lrxtciit oi print qi~~r~i:~cli~s,inrliiiling wuiicliiia. c~triidiii~.io lrrt ii-oiii th hnk. side of tlie road. clrar of trdfic, or, ~11ri-cpracticable, (xiii) lixtriil <,1 ;[I1 cuttings and iylies of grilontl I,asscrl a wliitc paint p;itcli. .i inclich wide by (I iticlics liigli. on tlirougli. the fences. lit-rbs. or pliiitlis, if ;my, 011 liotli des of thc road. may lie siilistitcttetl for iiitlcv pcgi. Each ;is well as ~i(isiticins,slioulrl IJC given for traverse peg or spiiic shoultl lie exactly oii line with the lity structures occurring at or near ground i-orrcspniiding iiair of Ixiiiit patclics. In tiiiibcretl Ic.vcl. i\ny other spc~iditiforinatioil litarin$ ti~ioiithe country the line slioultl lie marked. 111 arldition. by tlesigti Init not spcciticdlj- listed alicive slicultl I)e small liorseslioe~sliii~~etlI)lazes on both sides of all trees recortletl. within j feet uf tlie litre. tlrc cliainage king niarked oil '1'1~ tiictlrotl of rcctnngular orisets is preferred to !he blazes in characters 17; inch high upon ii 11atcli of ratlial coniicctions for recortling detail. as the former \\liite paint 1inches wide l)p 6 inches Irigh. siiiiplilics plotting. Recovery lqs, with index pegs as tlcscril)etl ;tbovr. 12. Proposed Deviations.--;\ sep:ir:ite 1iI:ii:. with longi- .j!iould be placed at right angles to t!ic liiic. 011 hoth tutlinal anrl cr(1ss rcctions. should be su1)mittctl for sirlcs. trppusite tlie appropri;tte centre liiie ~ieg.at inter- aiiy prriposc(1 (leviation. Tkviations slivultl be surveyed vals of joo feet :ind at all tangent points, aiid slioultl in accortlancc with 1-8, inclrisivc. almve. !)e iiiarlietl ILI'., with tlic chainage. I.1 Ire uffset dis- taiice slioultl be uniforni throughout, I*./ 13. Road Passing Through a Town.-.\iiy road passing ;CO feet, provided the 1qswill not 1)c (I tliwiigli :I m;iiii street of :I to\viisliip slioultl be surveyed constructiun or arc not placed outside r! iii accortl:ince with 29-38, incluhivc, Iicrea itcr. The positions of rcxcovery pegs slioulil !,c shown on thc Final Survey (New or Existing Route). Loclispits. 6 feet lniig. should be tlu;. in the direction 14. Chainage.-Tlic itistatice is to Iic ii:casuretl in a of the traverse :it each angle and at each 1.000 feet peg. direction a\v;iy from Sytlney. and is to lie measured 16. Level Datum.-Levels should be referred tn stan- :irouiitl the arc of c~irvcs.not acros the chord. clartl tlstum (mean sea-level at Fort Tk&oii) \vherever 15. Marking the Line.-Thc line .;lioultl I)e pertiin-- mitlily Ix,ssil)le. otlicrwise to any d.ii1;ni of \vliicll the iiciitly iiiarlictl at each IOO feet on t:iiigc.iits, a! all tail.. Icvd relative to sea-level is kiimvii :i~i~~rosirnately.'

I. TI1c top of tach peg slioultl be pxiiite(1 wliiie. ant1 1 he position of tlic actual pint upon wiicli tlie level staml)ctl with the chainage by nicans of ;h-i11c11(lies. -~~~~ ~~ ~~ ~ ~ . ~~ ~~ ~~~ ~~ ~~- .. \vater co,,.cr\ ,liOl, ,lXt,,,,, ,,, Stil,,

is to IIC taken should be intlicatetl Ly a broad arrow 21. General Information.-'hc surve;;or should sub- pointing to a small triaugle, thus, J, ~n trees tlie mit a report covering the following :--- 4 (i ) Suitable locations for construction camps and access m;irliings shoultl be chisellet1 to the tlime:isiotis given. roads, and w:itc'r supply facilities. (This applies Thc position ;itid tlesci-iption of encli lmicli iiiarli ~irincipI1~-tu \Yorks likely to IIC carried out hy day Ialiour.) siioultl be giveii in the tieitl book, and a list of I)riicii (ii) Location, naturc anrl extent of mark.;, with the ILL. of each, should be givw :it the saiid, gravel, and stnne. (Sample beginning of e;tch level book. nnly whrn callrll fur. I (iii) Tlic uaturc aucl quantity ni timber on the line, and 18. Accuracy of Levelling.-The traverse. ai iiiarltctl. the probahlc cmt per acre of clearing. -levclletl. 'Hie differelice between the (iv) The, nature of the earth and rock existing in the cuttings, as drterniined fnim tat id:$; the nature oi througli lcvel.; antl the cliecli levels s!ioultl not exceed the m;itcrials Rliich will iorni the iiew suli-grade, and I '3.02 oii any peg. 0.05 between beiicli nnrlts I mile thc slopes oi any existing batters in the same class of apart, or 0.5 V'Zwhere AI equals tlie length of the country. (No test pits are required where tht, road will he in embankment.) traverse in iiiilcs. (v) ThP naturr of thr sd-gradc am1 pavement on existinl: roads, as determirid irom narrnw treuches cut across 19. Longitudinal Section.--l.c~vcls sho:;kl lie talien at thr roadway at intervals not exceeding i,ooo i&. every 100 fcet. at every niarketl change of grade, at The thickness of the pavement should IK rncasurcd at street intersections ant1 angles, at ai! tangent lioints the ccntre ;ind at each cdge. disregarding any mixcd imtl recovery pegs. aiitl at such othcr points iis are i.arth and paving material just lielow the ~iavcment. (Samplcs are not required unless specially called f11r.1 nccessary to describe the road coiiipictcly. ,\ ll level.; (To be rorltillrrad.) should Iic taken on the top of the pegs. - 20. Cross Sections.-Cross sections slioultl lie taken at each 100 fcct. at all angles, at street iiitersectioiij Reconditioning with Premixed (extending io0 feet along the cross street. or far Macadam. rnougli to fix the approxim;itc grade of :lie street), oi- TILE reconditioiling of wavy tar and bituniinous at sucii shorter intervals as may be necessary. \\%ere pavements by surfacing with a thin sheet of premised the transverse inclination of the ground exceeds I in S, macatlam, sliread by dragging (described at length else- cross sections should be takcii at every peg aiitl every where in this issue), has been contiiiuctl. On the change of contour. Any iiiarl~edch;i::ge in thc sitir Great \\'estern Highway, between St. Marys and Vic- siopes on either side (,e.!/.,cliRs or overhanging iedges toria Bridge, Penrith, throogh tJaze11)rook. and over ,-j-ioo feet from the line) should be recortlcti on the sections I)ct\veen Slxingwootl nntl 11outit \'ictori:i ; cross sections. 011 existing roads ttic aligiiriimt lines on the Prince's tl ighway through Sutherland ; antl (whcre they can be easily cstablisheJ). the ceintrc of 011 the F1 uiiie I Iighway through Ratilcstown, and the roadway, the edges of the pveiiient atid form;i- between Cabramatta antl \\'arwick Farm? the pave- tion, any drain inverts. lcerbs. or icarertables, and ments have been smoothed and strengthened by this eiltrances to larms residences sho!.~ltllw tised as to process. Resultiiig from this satisfactory use of pre- position ancl lcvcl tivc to the travcrsc line. mixed macadam. short lengths of main roads have recently been treated by several coiiiicils. For ex- :\I1 cross sectinns slioultl he taben at riglit angles to atilple, in Condaniine-street and I'ittwater-road (, Manly :!le traverse line. csccl)t at ang-lcs (wlicn the cross Municipality and iVarringah Shire) a premised mac- section is to bc tdicti along the ha!i--anglej atid in adam wearing course has been applied to the wavy creek beds, \vheli the exact orientatiori should he re- sections of pavement. Other lengths will be given corded in t!:e field book. Cross scctioiis should es- similar attcntion in the near future, and it is hoped tilntl at lcast 30 feet on each side of the tra\erse. an>l to extend this cl:rss of work aillong the councils as a nore when necessary. c.9.. in rough country where means of rctluciiig maintenance costs as well as im- extensive cutting or filling is likely. proving the road surfaces. Tenders and Quotations Accepted. The acceptance by the respective Councils of the following Tenders has been approved by the Department during the month of April, 1932 :-

-~ ~ -~~ -~ \\'ark. I I Name of Amount of Recommended Tenderer. Rcccmniended Tendcr. Shire or Description. hlunieipalily. , t' 5. d. Erina ...... 10 Cncistrvrtion of concrctv hrirlgw over Cntrock and Ran-, liurt, Ik~ulton and 2.983 2 0 pnlow Creek<. 1 Hnywood Ltd. Ijverpool Plains ... ,ji CravFl con>trur:tiun. one mile. between 401 m. anrl -11: m. J. F. Court ...... 734 5 7 hlolwaree ...... 1 Constr~~ctionof concretc bridge at Mnrnlan...... 1 \V, 11. Mcllonald ... 501 I o 1 60 MAIN ROADS. Vol. 111, No. IO.

The following Tenders and Quotations were accepted by the Department during the month of April, 1932 :- Tenders.

Work. I Kame of Amount of hfunieipality or Snrcessfnl Tenderer. Accepted Tender. Shire. I I Description.

.! s. 11. Manning ...... IO 1 Construction of concrete and steel bridge, comprising two Hancock anrl \%"sbbPty. II,OT 11 J 1 120-feet truss syans anrl one fkfccl basc-lle opcming Ltd. span over Lansdowne River at Coopernook. i Patrick Phinu _.. 9 Construction of timber heam toridge. Igo-feet long, and R. P. Sylvestcr ... 1,927 0 0 paved earthwork approdies at Bowman's Creck. Lyndhorqt ... 6 Con-trnction of concrete bridge. 53 ket lonq, and pz'ed Burt, lloulton a~tl I,CS~<) 8 6 earthwork approachcs at Keliibula Creek. llaywood. Stroud ...... 1:o Snpplv and delivery of one 90 ft. 6 in. stcrl truss npnii for .Ii:stralian Iron and 703 .I 8 bridge over tlrc Myall River, Bu!ladelah. Stcel Ltd. -~ Quotations.

Amount 01 No. of Description of Article. Kame of SucceF-ful Tenderer. Accepted Quotation Quotation. - I s. d. Reinforced concretc pipcs. f.o.b. Eden, 15 in. dia.. 24 ft.: Hume Pipe (.o...... '3 4 jo in. dia., 122 ft.; f.o.b. Narooma-iS in. din., 96 feet; 21 in. dia., 75 ft.: 30 in. dia., 72 ft. Bridqc timber. delivered 28 m. weqt of Wnucl~ol?e-Iz in. x I I in., H. Iiirknian ...... I1 Io 32 ft.; 12 in. x 6 in.. 170 ft.; IO in. x 5 in., 1x4 ft.; 9 in. x 5 in., OZ ft.; 9 in. x 3 in., 8.j ft.; 8 in. x 8 in., 159 ft. ; Sin. x 4 in., 1,616 ft.; 6 in. x .$ in., 89 ft.: 1 in. x 4 in., 208 ft; 4 in. x 3 in., 100 ft.; 5 in. thick, 8 in.-Io in. wide, in 21 ft. .q in. Imgths, 6,732 sup. It. Bridge timber, delivered 28 m. west of \Va.uc!iope-io in. dia. H. Kirkmxn ...... '4 3 small cnd, 162 ft.; 12 in. dia. small end, 364 ft.; 18in. dia. at ccntre. 347 ft.; 12 in. dia. nt centre, 38 ft. Reinforced concrete pipcs, 18 in. dia.. 20 ft.; 15 in. dia., 80 it.; Hurnr Pipe Co...... I8 0 IZ in. (!ia., 20 ft. Broken stone, f in., 900 tons ...... Way and \Yorks Branch ...... 00 Rroken stone--z.?-tons qin.; 20 tons, $ in. ; IO tons, zt in. Sydnev & SiihurlJan Illiic Mrtnl (juar- 63 ries. 75 tons, 8 in.; Go tons, f in.; 70 tons. id in.: .lo tons. z+ in. Swthcv I3liie \?eta1 Qnarrics ... 32 12 6 Uridge timber, delivered Cock!c Creek-15 in. x 14 in. 3 ft.; J. Croll and Fons ...... 0211 6 IZ in. x 6 in., 21 ft,: 12 in. x 5 in., joo ft. : 12 in. x 4 in.. 42 ft. ; 11 in. x S in., 20; ft.; 4 in. thick, in 16 ft. 6 in. Icngths. Sin:- IO in. wide, 3,300 sup. ft. Rridqc timber, delivered at Cocklc Crcrk-14 in. x 12 in., 207 LY. n. Wood ...... ft.: 16 in. dia. at small end, Z.L ft. Sand. 300 tons ...... i~lenlieldSand (.n...... Hardwood, f.0.r. Waterfall--t, in. x z in., 2.5.000 lin. it.; pegs, Maxwell Porter mil Sotis ...... 5 in. x 2 in. x 21 in., pointed on 3 sirlw, 4.500. StAreinforcement, 79+ rmt...... State Mni'ici- Pipc \~~rl<.i...... BridSe timbcr, 1.o.r. Yass town--Iz in. s 6 in., 141 ft.: IO in. s Jovph Rrid 1.td...... ; in., 100 ft.: 9 in. x 5 in. 36 ft.: 8 in. x 4 in., 1.o14 ft. COVCI' plates. complet? with holts. h pairs ...... \Ya!ch Islonil I~ockyarrl ...... 2212 0 Tar (coke oven)-I2,ooO gals...... R.H.1'. 13~-l'ro:lucts 1.td...... 175 0 0 ...... 433 0 0 ...... 5216 3

Pilr sliors--G ...... \Valsh 1-land liockyald .. , ...... I970 Iceinforced concrete pipes. 24 in. dia., 129 ft...... R. Fomlcr. Vianini Ltd...... 79 0 1 Steel reinlorrement-=,~og tons ...... Statc Mouicr Pipc \Vorks ...... 71 I: IJ Rridgc timber. dolivered IZ~m. north of Kenipsc)J~- 12 in. x 6 ia. F. \V. Lane ...... 466 5 I 49tft.: roin.xsin.,ir4iI.; oin.x3in.,ozft.: 8in.sSin. 462 ft.: 8 in. x 4 in., 2.279 ft.; X in. x j in., io1 ft. Bridqc timber. dclivcred IZ+ m. nnrth of Kempsey-12 in. dia C. W. Iicrans ...... , small end, 1.026 ft.; 10 in. dia. -mall end. 2-12... ft. : IQin. dia at centre, z15 ft.; 18 in. dia. at centre. ,558 It. ; I; in. dia. at centre. 293 it.: I2 in. dia. at rentre, 7h It. Rridae timber, delivered at Mvllett Crecli, 2 m. from Unanderra W. Watt and Son ...... 6orr o -18 in. dia. at small end. go ft.: R in. x 4 in., 840 [I,. Tar, No. 2, qpraycd un Pacific Highway. 29 m. north of Gosford B.H.P. By-Prodrcrs Pty. Ltd...... , 170 I2 G ---4,200 gallons. Bridre timher, f.0.r. Yass toa-n--rg in. dia. small cnd. 257 ft.: J. A. Cooper ...... I' '1 6 rG in. &a. small md, j~ it.