L I -. . :,ruL39_s 1 ll i i DECEMBER 1972

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JOURNAL OF THE DEPARTMENT OF MAIN ROADS,

DECEMBER, 1972 PRICE It was really not so long ago-in 1947-that F$ty Cents man first flew faster than the speed of sound. VOLUME 38 NUMBER 2 For test pilots of supersonic aircraft, breaking ANNUAL SUBSCRIPTION the sound harrier must initially have been an Issued quarterly by the Two Dollars awesome experience. Now it is commonplace, Commissioner for Main Roads hut then it was a step into the unknown that Post Free called for courage, determination, and en- R. J. S. Thomas durance. Editors may use information With similar determination, at the recent Additional copies of this Journal contained in this Journal, Olympic Games, athletes from all nations may be obtained from pitted themselves in contest against each unless specially indicated other and against man’s old enemy “Time”. Department of Main Roads to the contrary, In swimming and track events the greatcst 309 Castlereagh Street provided the exact reference challenge was to heat the clock and world records fell with remarkable rapidity as con- , h’ew South Wales, Australia thereto is quoted testants set out to heat the old harriers . . . and did. Such talk of attitudes and harriers is not as unrelated to roads and driving as it may CONTENTS seem, insofar as there is, within many of us, a sort of psychological harrier that makes us 34 -Bitumen sealed from end to end feel that long strctches of gravel road are 41 BARRIER HIGHWAY JOURNEY-Notes for tourists too much for us to cope with. We often baulk at the prospect of driving on anything but 44 SCALE MODELS HELP BLIND CHILDREN hi t umen. 46 WESTERN DISTRIBUTOR-New city expressway for Sydney To be on a dirt track, or even on a freshly graded highway, might mean adven- 47 NEW BRIDGES FOR SOUTHERN EXPRESSWAY SOUTH OF ture to some, hut to many-cspecially those WOLLONGONG (colour photographs) on business and not on holiday-it brings 48 BARRIER HIGHWAY HIGHLIGHTS (colour photographs) feelings of uneasiness, isolation, and irri- tation. City dwcllcrs frequently become 50 -Improvements between Bathurst and Wellington impatient when their link with civilizotion is (colour photographs) restricted to a rough road and they are 51 FAR AND NEAR-A report on road and bridge works around the State generally eagcr to “get off the gravel”. In contrast, a return to “the bitumen” induces MITCHELL HIGHWAY: Completion of sealing-Bridges north of Molong feelings of comfort and closeness-in spite of 52 : Final sealing almost finished long distances. Besides other benefits, there is something satisfying about a bitumen : Full length sealing nears completion-New bridge at surfaced road that brings a sense of certainty, Narrabri-New bridge south of Moree safety and confidence. PRINCE’S HlGHWAY: Boydtown-Kiah--Rig bridge for Bega Obviously the answer to these attitudes is not a call for less timid drivers hut the pro- 53 : New bridge at Ellenborough vision of more sealed routes. The solution PAClFIC HIGHWAY: New bridge at Telegraph Point thus depends not on the motorist’s frame of : New bridge at Gundagai-Twin bridges near Mittagong mind hut rather on the Department’s deter- 54 mination, capabilities, and capacity for LAKE ILLAWARRA CROSSING WIDENED AT WINDANG continued exertion. If adequate funds are 55 : Still more bitumen-Lightning Ridge available, there is no limit to what can be done. In a vast state like New South Wales 55 SYDNEY HARBOUR BRIDGE ACCOUNT-Income and expenditure for and in a society so set on individual vehicular the year ended 30th June, 1972. travel, the community relies on bitumen 56 STATEMENT OF RECEIPTS AND PAYMENTS, for year ended 30th June, 1972 surfaced roads to reduce slow travelling times, to defeat the tyranny of distance, and to 58 NEW BRIDGE AT CAMDEN: Selecting the type of structure-Prestressing by dispcl the dilemma of having to drive on controlled lowering-Fabricating the girders-Erecting the girders gravel-or not at all. The completion of the sealing of the 63 TENDERS ACCEPTED BY COUNCILS Barrier Highway last October, and of another 64 TENDERS ACCEPTED BY DEPARTMENT OF MAIN ROADS three highways within the next I2 months (see articles on pages 34, 51 and 53), will at least in some areas take the trauma out of * * * * * travel for those who are undcrstandahly reluctant to try unsealed roads. Front Cover: Barrier Highway The surfacing of the last links on these important highways will heighten our State’s Top Left: Straight, smooth section, at forty miles east of tourist potential, open up new possibilities Centre Right: A “rorkbuster” in operation durinf construction of Maccullochs Range for caravanners and pave the way for the Bottom: New bridge over Tallyawalka Creek, 22.5 miles east of easier distribution of produce and livestock. Thereafter, motorists on these routes will * See also centre page illustrations and articles beginning on pages 34 and 41 he released from the frustrating and inhibiting limitations of gravel and dirt pavements. Back Cover: Construction of the new bridge over Brisbane Water at “The Rig”. Without the old barriers, they will find that, on sealed roads, getting there can he half the fun.

DECEMBER, 1972 PAGE 33 THE BARRIER HIGHWAY Bitumen Sealed From End to End The Barrier Highway, principal overland route through the central western district of New South Wales, has now been bitumen surfaced over its entire 400 mile length. Extending from in central New South Wales to the South Australian border via Cobar, Wilcannia and Broken Hi’ll, the Barrier Highway forms part of National Route No. 32. A bitumen surface is now provided over the full length of this National Route which connects Sydney and via Bathurst, , , (in New South Wales), Oodlawirra, Burra and Gawler, (in ).

EARLY DAYS ALONG THE For many years the was soon established by “bullockies” and ROUTE the most important supply route for their teams. The route of the Barrier Highway was western settlers and their only outlet for In 1871, a road was marked out from proclaimed in 1929 and named in 1959 produce. The first steamer (the “Albury”, the copper field at Cobar to Bourke and after the Barrier Range from which ore piloted by Captain Francis Cadell) navi- water supplies for the use of teamsters is mined at Broken Hill. gated the Darling River as far as Mt were provided by the sinking of taiiks. A Explorer Charles Sturt named the Murchison (Wilcannia) in 1859, com- coach service was established from Range in November 1844, at first calling mencing a river trade which remained Hillston to Bourke in 1875, giving a it Stanley’s Barrier Range after Lord vigorous for many years. As late as 1890, north-south crossing of the country now Stanley, then principal Secretary of over ninety steamers were regularly traversed from east to west by the Harriet State for the Colonies. Writing later in employed on the river. Highway. his Journal, Sturt shortened the name to The development of the road system in By this time the tracks established by Barrier Range. the west was given impetus by the dis- the mail carriers were reasonably defined The early 19th century explorers of covery of copper at several places during and by 1882 the mail route extended from western New South Wales generally the 1860’s. Ore needed transportation Warren through Nyngan, Hermitage confined their journeys to the lands from the mines for treatment and routes Plains () and Cobar to a road adjoining the Lachlan, Bogan and Darling from mineheads to river wharves were which linked Ivanhoe with Milparinka. Rivers, along which they travelled. It was left to the graziers and shepherds who followed to explore further into the vast It IS easiergoing now for this 1918 truck, which was the first to carry mailfrom Wilcannia tract of country through which the to Ivanhoe as well as being first over the completed Maccullochs Range deviation. Barrier Highway now runs. At first settlement expanded into the v I .I I area along the route of the Murrumbidgee River to its junction with the Murray River and then northeast along the Darling River. Some settlers had moved into the Wilcannia district by 1850. How- i ever, the absence of permanent water on land away from these rivers made settle- ment over wide areas hazardous. Squatters were reluctant to take up land away from the river frontages because of the diffi- culty of moving sheep and cattle across wide stretches of waterless country. It was not until the 1860’s that general settlement reached the land between the Darling River and the South Australian border.

PAGE 34 MAIN ROADS This mail route continued west, crossed six municipalities of Broken Hill, Bourke, incorporated into the newly created the Darling River at Wilcannia, then Brewarrina, Cobar, Wentworth and Murray-Darling Division, with its head- on to Mt Gipps (about 16 miles north Wilcannia. Roadworks in the unincor- quarters at Broken Hill. On 1st January, of Broken Hill) and the South Australian porated area outside the municipalities 1956 the Central-Western Division border. were previously under the control of the (Parkes) assumed direct control, from By 1884 a road had been surveyed Department of Public Works and for officers of the Department of Public between Nyngan and Wilcannia, along administration purposes, the Western Works, of roadworks, bridges and ferries the tracks established by the mailmen, Division was divided into four districts, in the Bourke district. When the Central and by 1889 a road existed between viz., Broken Hill, Bourke, Cobar and Hay Northern Division was established at Wilcannia and Silverton via Mount Gipps. (although Hay was outside the Division’s Bourke on 1st March, 1962, the responsi- The final link in the route of the Barrier boundaries). bility for reconstruction of those portions Highway, the section between Silverton Following the transfer of control of the Barrier Highway within the Shires and Cockburn, was in use by 1897. Later (which was formally authorised when the of Cobar and Bogan was transferred to this route was altered to pass through Main Roads (Amendment) Act came it. Broken Hill and Thackaringa to the into force on 27th July, 19361, the The Central Northern Division has South Australian border. District Engineers of the Department of reconstructed approximately 142 miles of By the turn of the century the route of Public Works continued to supervise the Highway, the Murray-Darling the Barrier Highway was well established work on behalf of the Department of Division 203 miles and the balance of the and already serving a similar role to that Main Roads in the Broken Hill, Bourke work has been performed by of today’s Highway. and Hay districts. Supervision of work Council on behalf of the Department. DEPARTMENT’S RESPONSIBILITY within the Cobar district was undertaken The construction of the Barrier On 2nd September, 1935 the Depart- directly by this Dcpartmcnt’s Central Highway from 30 miles east of Cobar ment assumed control of all public roads Western Division at Parkes. to 30 miles west of Broken Hill has in the Western Division of New South As from 1st August, 1955 the districts been undertaken by construction teams Wales as well as of Main Roads in the centred on Broken Hill and Cobar were working from camps at various locations

DECEMBER, 1972 PACE 35 controlled by Works Offices at Broken Earthworks Hill, Cobar and Wilcannia, the last More than 4 million cubic yards of named having been established in 1967 earthworks were carried out in pre- to complete the work both east and paration for the construction of the west of that town. pavement. The Barrier Highway traverses flat to RECONSTRUCTION AND undulating country throughout. Along BITUMINOUS SURFACING the route the soil is generally fine red loam but the road also crosses some Forty years ago the Barrier Highway gravel ridges, rocky outcrops and sand was a defined earth track with occasional dunes. In the sand and clay areas, earth- minor improvements. Today it is a smooth works were carried out using tractor/ bitumen highway designed over most of scoop combinations, elevating graders or its length to a 60 mph standard. elevating scrapers in association with The programme of reconstruction on various types of rollers, graders and the Barrier Highway commenced in 1953. watering equipment. On the range areas, this became an even more pressing At this time the only sealed sections were additional equipment in the form of problem with evaporation at its highest in the towns of Broken Hill and Cobar. explosives, jack hammers and heavy and constant watering was necessary to Outside these urban areas, the road tractor-dozers were required for ex- maintain the correct moisture content for pavement consisted largely of the natural cavation of rock. compaction. material through which the road Water was obtained hy the Department Drainage formation passed and only very clayey or from public watering places when sandy sections were stabilistd with gravel The Barrier Highway crosses one of the possible, but this practice often necessi- or sand clay. Bridges and culverts were driest areas of the State but ironically tated haulage over long disiances. few and most of the larger watercourses drainage facilities have formed a major Consequently, tanks to collect anti. store merely had gravelled causeways. part in overall construction. A feature of rainfall were constructed alnng the route By 1955, the Department had completed the harsh climate is occasional heavy of the roadworks and water was also sealing on the 30.6 mile section from downpours which cause the sudden purchased from privately owned bores Broken Hill to the South Australian flooding of the many undisciplined water- within shorter hauling distances. border. courses across the plains. To obtain sufficient quantities of' water Bituminous surfacing on another major Since commencing reconstruction, the the Department also found it necessary section, connecting the towns of Cobar Department has constructed over 100 on a number of occasions to resort to the and Nyngan, was completed in December, bridges and almost 47,000 linear feet of more expensive alternative of sinking its 1969. On this section, the Department's culverts across the numerous watercourses own bores to tap artesian supplies. Water forces progressively extended the bitumi- along the Barrier Highway. In addition, was pumped up from approximately 300 ous surface in an easterly direction from it has also been necessary to provide feet below ground lecel and earth-hanked Cobar, while Rogan Shire Council under- approximately 80 causeways and flood- storage dams (tanks) of up to 800,000 took construction, on behalf of the ways to cater for maximum waterway gallons were constructed. Department, westwards from Nyngan. needs at a number of locations. Water was conveyed froni these dams During the period when reconstruction Pavement Construcrion to the roadworks in Departmental water was underway between Cobar and tankers with a maximum capacity of 3,000 A total of 1,363,ooO cubic yards of Nyngan it &as also in progress easterly gallons and as many as 13 of these tankers from Broken Hill and westerly from gravel was used to construct the base and were in use simultaneously. Cobar. The sealing of the pavement surface courses of the road pavement. It is estimated that during thc con- These materials were generally obtained between Broken Hill and Wilcannia struction of the 39-mile long deviation from pits excavated along the route and was completed and in use by November along Maccullochs Range the Department were handled by a combination of front 1970, and by this date work was well used over 26,000,000 gallons of water in end loaders and trucks. advanced on the remaining stretch compaction operations. between Wilcannia and Cobar. The Almost 2 million gallons of bitumen has . . . and too much last section of roadworks undertaken been used in the sealing of the road was the construction of a deviation pavement and approximately 83,000 cubic Fluctuations from one weather extreme over Maccullochs Range (see more yards of coverage aggregate were in- to another are a feature of the west, and details on page 39). corporated into the bitumen seal on the the threat of damage to the road pavement pavement. Half of this material was by scouring during heavy showers of Design screened slag from Cobar, while the rain, was an additional prohlem faced by Initially, the design for reconstruction balance consisted of local ridge gravel and the Department's engineers and workmen. of the Highway provided for a flush niaterisl from Broken Hill quarries. Dust was another constant hindrance sealed pavement 18 feet wide on a 26 feet THE DISRUPTIVE ELEMENTS to construction. The hot dry iclimate wide formation. However, the dimensions combined with the constant use of Too little . . . were increased later to a 20 feet wide sidetracks and haul roads by trucks and pavement on a 28 feet wide formation In an area where the average rainfall road plant, caused disintegration of the and since 1962 all construction has been is under 10 inches the provision of water fine red soil into laycrs or dust. Road- to a standard of a 22 feet wide pavement for construction purposes was a major works were frequently interrupted and on a 34 feet wide formation. difficulty. During the summer months delayed by the need to rescue heavily-

PAGE 36 MAIN HOADS DECEMHER, 1972 PAGE 37 PAOE 38 MAIN ROADS laden gravel trucks and other equipment deviation from the original route in use "lonely mountains, rocky, barren and bogged in dense, deep pockets of unstable for many years. This route passed to the cheerless." dust. north of the Range across a number of low-lying areas which form shallow Expenditure THE FINAL LINK-MACCULLOCHS lakes after rain. RANGE DEVIATION The total cost of the reconstruction To eliminate the problem of flooding and bituminous surfacing of the Barrier "a range of Saiidstone hills. IyinR in the on the Highway, a new route running Highway since 1953 (including the vast flat desert between the Bugon and along the Range was chosen and this is Maccullochs Range deviation) has been Darling Rivers. Some of these hills are about three miles shorter in length than almost $16 million. peaked and others flat-topped and stand the previous route. like lonely mountains, rocky, barren and Construction of the deviation was ROADSIDE REST AREAS cheerless." carried out ovcr a three year period and This quotation from Railliere's I870 in very difficult conditions. All work Motorists using the Barrier Highway Gazetteer of New South Wales aptly sets was performed by the Department's own today will not experience the rough the mood of the Maccullochs Range forces attached to Wilcannia Works conditions encountered by travellers at where work on the final stage in the Office with an average of between 20 and the turn of the century or more recently programme to seal the Barrier Highway 25 men employed at all times on the by construction teams. However, the flat, has just been completed. project. fairly monotonous nature of the country, Although rising to a height of only 300 the climate (particularly summer heat) The 39-mile deviation cost approxi- feet above the surrounding area, and long distances between settlements mately $2.5 million or $64,000 per mile. Maccullochs Range earns its name by can create conditions which are unfamiliar The road pavement throughout is 22 feet virtue of being the only vertical feature and uncomfortable to many drivers and wide with 6 feet wide shoulders and has over hundreds of miles of central western their passengers been flush sealed with two coats of bitu- plains. Approaching from Cobar it To assist travellers to overcome these men. Of the aggregate incorporated in the commences 40 miles east of Wilcannia, problems and to enjoy the journey more surface of the deviation, 91% was obtained and extends in an east-west direction by taking out some of the strain of from Cobar, where stockpiles of slag from for 12.5 miles. covering massive mileages without a the copper mines were screened to yield Major Thomas Mitchell, leader of an break, a series of roadside rest arcas has suitably shed materials. expedition sent to explore the course of been established along the Highway. the Darling River, came upon the Range Fifty-three different items of plant were These areas are provided with shelters, on 24th June, 1835 and named it after employed during construction of the tables and seats, fireplaces, firewood, his friend John Macculloch, a Scottish deviation. On the Range, elevating self- drinking water and litter bins. doctor and geologist. Macculloch, who loading scrapers were used to perform The Department has constructed six gave up his medical career in 1811 to the required earthworks and also rest areas along the route, the last of pursue his interests in geology and assisted in winning and placing some of the these being on the southern side of the mineralogy, died only a few months after basecourse loams. To achieve adequate Highway, 34 miles east of Wilcannia, near his name was given to this Range. breakdown of the pavement gravels, the site of the ceremony to mark the which were laid over the fine-grained The New Deviation sealing of the final section (see details on sandy loams of the basecourses, rock- page 40). The other rest areas are located The work on the Maccullochs Range busters, as well as rollers, were used. at: section of the Barrier Highway is a A "rockbuster" is a mobile hammer mill which is towed over a windrow * 52 miles west of Nyngan. of rocks and through the action of * 42 miles west of Cobar. revolving hammers, reduces oversize rocks * 73.9 miles west or Cobar. to useable size in one operation (see * 57 miles east of Wilcannia. photographs on front cover and at left). * 76 miles east of Broken Hill. Principal quantities involved in con- A FINE THREAD AGAINST struction of the section over Maccullochs ISOLATION Range were: Earthworks . . 808,400 cubic yards Stories of the hardships and isolation Pipe and Box Cul- faced by Australia's early settlers have become a major part of our folklore. verts . . .. 8,350 linear feet Base and Surface Many of these stories relate back to the Course Area . . 625,091 square yards experiences of pioneers in the region of Sealed Area . . 499,950 square yards New South Wales now served by the Water . . . . 26,000,000 gallons Barrier Highway. This inhospitable, dry country had little to endear it to early Driving up maximum grades of only settlers, many of whom had been reared 4.4 for 1,730 feet present-day motorists in the lush greenery of the English might be excused for failing to notice the countryside. But settle it they did, learning Range at all, and, in view of the sense of to survive the heat, the droughts, the security and unity engendered by an all- dust and the occasionally devastating bitumen highway, it is unlikely that any floods. Perhaps the greatest hardship of future description will refer to them as all was isolation. For many out west

DECEMBER, 1972 PAGE 39 isolation remains, but is gradually being to Bathurst and the Mitchell Highway the social and economic significance of diminished by modern communications. from Bathurst to Nyngan, the Barrier good roads in this area of New South To combat isolation good road links Highway now provides a fully sealed Wales has long been recognised by the are essential. To the inhabitants of this route between Sydney and the far western Department. sparsely settled region who derive their boundary of New South Wales, a distance The high standard of travelling si.irface livelihood for the main part from widely of almost 760 miles. achieved by the reconstruction of the scattered pastoral and mining activities, Thcse important western highways Barrier Highway guarantees the motorist the Barrier Highway is the principal carry an increasing volume of traffic. In a safe, fast and comfortable journey. road which connects them with their 1970, the average daily count on the These benefits are now availablc not neighbours, with the towns through which Barrier Highway ranged from 120 vehicles only to the local population but also to their essential goods and services are a day on the least trafficked sections to the large number of intrastate and inter- distributed and with the east coast. As 450 on the heaviest. Although these state travellers (including businessmen, part of a network of roads which includes daily traffic volumes do not even equal tourists and long distance hauliers) who the from Sydney the hourly volumes on some city roads, pass along the Barrier Highhay.

Macquarie Placc, Sydney from which road mileages are still measured. The designs on both sides of the medallion have been reproduced on the plaque mentioned above and appear in the illustration on page 34. The medallions were handed out at the official ceremony and arrangements were also made to distribute them at schools along the Highway between Nyngan and Broken Hill. School students living near " the Highway now have two tangible '4 reminders of the importance of the completion of this work-a medallion on L one hand and on the other, the actual bitumen sealed Highway itself. It is hoped that both will prove valuable assets to them in the years ahead. All the medallions have heen distributed and no further request for them can be jirlfilled. FINAL SEALING AND OFFICIAL S. Thomas) and the President of the However, for those who wish to obtain a "souvenir" of the ocrusion, supplies

PAGE 40 MAIN ROADS Motorists heading west away from the hectic east will now tind a great deal of pleasure and relaxation in travelling the all-bitumen Rarricr Highway. Where once such a trip BARRI€R HlGHWhY JOURN€Y could turn into an ordeal-especially in wet weather--and required more than a touch of tenacity, tourists and ”locals” need no longer curse the condition of the road. For present-day “explorers” using the newly-sealed highway. it is a far o.y from the *- hardships experienced by Charles Sturt and a rx’ his party when, in the mid-1840’s. they passed through the Broken Hill region. Frus- trated by their slow progress across the rocky landscape (and obviously aware of the “Macadam” method of roadmaking which was introduced into New South Wales in the early 1820’s) Sturt wrote “. . . it appeared as if McAdam had emptied every stone he ever brqke to be strewed over this metalled region!” He would be pleased to know that such sfoney impediments-at least for east- COBAR over 500 people. Situated 7 miles out on the west travellers-have at last becn buried Louth Road, this modern mine uses diesel under bitumen. Concentrated in and around Cobar-“the po:vered trackless, rubber-tyred load-haul- Observant travellers along the Barrier Copper City”-is an interesting contrast dump units (of 6-ton capacity) at levels Highway may see many emus, frcquent between old and new mining methods. Head 1,200 and 1,800 feet below the surface. To kangaroos, occasional echidnas, a few foxes, framer of the Fort Bourkc, Chcsney and satisfy town needs as well as the mines thirst most likely a large lone eagle and probably New Occidental (Gold) Mines are still for over 130 million gallons each ycar, water huge Rocks of chattering cockatoos and standing as tangible evidence of a mining is pipcd from the Macquarie River near galahs. history that dates back to thc discovcry of Warren, more than 120 miles to the east. Approaching Broken Hill, the Western copper here in 1869. Mining developed Despite severe droughts, a rich wool Plains present an immense “horizon-hitting” quickly and continued until 1919, when lower industry has played an important economic ren-brown landscape while elsewhere along grade ore, low prices, rising costs and a water role in Cobar‘s history and has been largely the Highway there is a comforting abundance shortage caused the closure of most mines. responsible for the continued existence of the of trees and small shrubs. The vegetation The last of the lar:e producers, C.S.A. Mines, town during periods of low mining activity. itself brings a reward to those who look was closed in 1920 following a fire. It is said It began back in 1862, when sheep were closely, as many species of wildflowers and that C.S.A. Co. was named after the original introduced primarily as a source of food. unusual plant life grow within view of the (1871) discoverers at that site-who were a 0 On Fort Bourke Hill (east of Cobar) there road and are particularly attractive after Cornishman, a Scotsman and an Australian. still stands the hand-placed stone walls of a seasons of heavy rainfall. At first, wagon loads of ore were dragged group of buildings, now known as Towser’s An appreciation of the beauty of these north by bullock teams to Bourke, for ship- Huts-.after the man who built them in the plains often depcnds on the season of travel ment down the Darling River to Adelaide, late 1800’s. The huts were rented to miners or the weather encountered, as well as the but later a more direct route (now Main and charcoal burners working in the area Road No. 407) was established across to and their layout has earned for them the degree of interest and anticipation in the somc to “eyes of the beholder”. It is not an area that Louth, while was carried west claim of being “Australia’s first motel”. openly reveals itself to sidewajs glances at Wilcannia, where shipping was more certain. 17Situated alongside the Barrier Highway at sixty miles per hour! Prior to 1900, Cobar had a population of the eastern end of Cobar is the impressive about 10,000 (compared aith 3,740 to-dav) Pastoral, Mining, and Technological and, as well as the mining companies, it Museum. The 2-storey building was erected TAKE A LONGEK LOOK boasled 14 copper smelters and even its own in 1910 and used for 10 years as the general Stock Exchange. Teams of men constantly office of the Great Cobar Ltd mining com- En route to the Silver City, the towns of scoured the countryside cutting timber for pany. In addition to a “walk-in” rection rep- Cobar and Wilcannia deserve more than a the wood-burning smelters. Nothing remains resenting an old mine, the museum contains brief stop or a quick dash down the main of these smelters except the large slag dump exhibits on geology, botany, entomology. street. Only a longer stay allows visitors to at the eastern entrance to the town. This aspects of pastoral life, aboriginal artifacts, get the feel of the “far” country. In addition, accumulation of “waste” is now being crushed and the general history of the district. some brief research may also save those who and used in some roadmaking and con- 0 Visitors to Cobar may also inspect the are passing through from inadvertcntlv missing creting. Commonwealth Meteorological Station (on otherwisc unrecognized reminders of the past. Between 1935 and 1953 New Occidental the Louth Road) and watch the release of a Such reading will certainly help them to G&l \line\ N.L. operated in Cobar and in weather balloon (twice daily). grasp the drama and history of those hectic 1957 Cobar Mines Pty I.ld purchased its heydays when as mining boom town and minine IC.RW\ and itlher asds. Followinr thc Aboriginal Poinrings at Mt Grenfell busy river port these were prosperous places- IircaiiiTn of ore-bodies at greater depthsihnn thronging with people and throbbing with prcuously worked. shaft

C‘OBAK Cohar Court House (at left) in Barton Street was built in 1882 and is an elegant link with the part. It is a contrast in style to Towser’s Huts (see text) and to the modern high school (1966). with its double rod. hreezeuwa and spacious landscaped setling. Changing shaper and sizeel cm also be seen (at nyhl) ~n lhis trio of shops (cirya 1889. 1895, and 1910) fronting Marshall Street on the route or the Barrier Highway through Ihe torn.

PAGE 41 DECEMBER, 1972 BROKEN HILL

Right: Probably Ihe ht-known building in the city is the unusual Post Olfice in Argent Street. Next Io it stands a Town Hall of victorian vintage and with a foundation stone laid by Sir,Henry Pmkrs ('The Father of Federation") on 3rd April. 1890.

COBAR . . . rontinued WILCANNIA E.vq., of Netallir station". After managing .Mt With fewer than 1,000 residents, Wilcannia Murchison station, Dickens set up business all within 400 yards of the car park. Also in is now much quieter than a century ago when in Wilcannia in 1882. He was M.L.A. for the area are a number of fish fossils and steamer traffic on the Darling River made it a Wilcannia from 1889 to 1894 and died at fossili7ed footprints. major inland port (probably the third largest Moree in 1902. It is interesting to note that the name in Australia-cven though 1,300 miles from U Those looking for other unusual and in- "Cobar" is probably derived from "copar" the sea!). It was surveyed and proclaimed a triguing links with the past might drive out (or "coburra") an ahoriginal term for the town in 1864 and in I880 the gold rush to Mt to the cemetery to see the gravestone of ochre with which they daubed themselves Browne (200 miles northwest near the Sergeant Major Parr. Parr was one of the on ceremonial occasions. Queensland border) brought a burst of pros- "Glorious Six Hundrtd" who rode in the perity. Another boom came following the famous, ill-fated Charge of the Light Brigade discovery of opals at White Clifls (60 miles (1854) during the Crimean War. . .and sur- north) in 1889-with Wilcannia merchants vived to add his name to the early pioneers selling supplies to the diggers. However, the of the Wilcannia district. extension of the railway to Rourke in 1885 0 The bridge over the Darling Ricer was COBA R and to Cobar in 1892 meant that river trade opened to traffic on lllh January, 1896, and Relow: This monument-known familiarly as "the declined and business eventually dwindled. is a classic example of the vertical Itft-span Strle"-war sculntumd by Pat Brooks (a former Cobar Nevertheless, Wilcannia's surfeit of superb structures built over western rivers about that resitlent). erected heside the Barrier Hiehwuay, near the sandstone buildings still surprise? many Museon:. by Ihe Cohar Chsmber of Commerce and time. On the southwest hank is a cottage uiiveiled on 29th August. IYOY, by Hon. W. C. Fife. travellers, who expect something less sub- once used as the "bridge keeper's'' residence. Miimter for Minej. stantial. Some worth seeing are: while at the corner of Reid and Cleaton The design features the mylhicvl bird, thc phoenix. In Reid Street ri\ing up with the ~cicntificsymbol for coppci held in its Streets is the Court House Hotel. fornierly heak. This reprerents Cuhur'a rchirlh through Ihe re- 0 Court House and Police Station (1878)- the Punt Hotel and presumably situated EommCnCeiiienl of copper mining m the 1960's afler a and prison. adjacent to the site of an earlier river crossing. lapse "f 40 years.'< (1878), The inscriptinn Compbcll Hcwlmrm Gibb and rhr U Museum previously belonging to In 1874 Charles Smith operated a punt and &rlpal" refers fn the 3 wellknken whb m 1869 found Rich and Co., merchants. a pontoon bridge-said to carry sheep across green-colnured rock at an ahoriginal water-hole. It was Post Office and Customs House next at the rate of 4,000 per hour! I.tIcr iocnlitird as copper-hearing ore by Mrs Kruse, door (now a private residence). %ho had hecn a '*halgil"--th~~tis U woman who. in the mines of Cornwall (England). hantl-picked the ore 0 Bank of New South Wales. BROKEN HILL on the conveyor hells hefnre it wai milled. The land In Ross Street near the water-hole was purchaqed in Oclober 1870 and subsequently hecamc the site of the Grcet'Coha; 0 Golf Club, originally Resch and Co.'s There are a number of informativc books Mine. once rcputal 10 he the higgest copper mine in Lion Brewery (IX85), one of the first in and descriptive tourist brochures about the the world. the State. Silver Cily which tell the story of its remark- U Hospital (1879), now with additions and able development. This article will therefore Pi on call to Royal Flying Doctor Service. simply spotlight some of the subjects and In Myers Street sights which may attract visitors who are 0 SI James Church of England (1883). "browsing around" Broken Hili. While speaking of churches it is worth 0 A mine inspection i$ a "must". Today adding that the Illustrated Sydney News of four large companies are operating-North 4th September, 1880, reported: "TIE Broken Hill Ltd, Minerals, Mining and marriap is annoimred at Wilcannia, recently, Metalling Ltd, Zinc Corporation Ltd, and of Mr Edward Rulwer Lytton Dickens, a son New Broken Hill Consolidated Ltd. Formed of Mr Charles Dickens, the celebrated writer, by the first syndicate in 1885, the Broken and Miss flesailly, dorighter ofA/jrrd Desailly, Hill Proprietary Co. Ltd grew to be

WILCAh'rVI.4 WILCAh'NIA Below: Aboriginal girls fishing from bank of Darling Below: On the same river almcst 90 yean ago (in 18x4) River at Wilcannia. oarsmen of the Wilcannia Roaing Club paurrd to pose for posterity. (By EOUII~SY of Wafer Conservation and Itrigation Commission.)

PAGE 42 MAIN ROADS BROKtN HILL Left: Further along Ar~centStreet is a vast verandah of ironwork framing the Palace Hotel--and thc Visitors' lnformution Centre.

Right: In contrait. this contemporary Civic Ccntre in Chloride Street features modern facilities for a wide range of public functions and cullural activilics.

Australia's largest company but when the blossoms about September each year and is yachting and swimming, and nearby Copi "Big Mine" closed down in 1939, B.H.P. protected. Hollow for power-boating and water-skiing. left the city to move into the iron and steel 0 By appointment, visitors can observe * and Mootwingee (82 miles northeast), an industries (including shipbuilding) with broadcasts of the unique "School of the aboriginal tribal ground with many rock centres at Newcastle. Port Kembla, Why?.lla, Air" from the studio at North School in carvings and paintinxm etc. Lane Street. Instituted by Ihe Department of The mining companies, together with the Education in 1956, it goes "on the air" * City Council, have established regeneration through the Royal Flying Doctor Service areas around the city-transforming semi- Network of transmitters and rewivcrs to arid areas into a perimeter of greenery. Early cliildren scattercd over 500.000 square miles work in the 1930's was based on recommend- of tbe outback. ations of the late Albert Morris. 0 Situated 5 miles east of the city on the U At the corner of Chloride and Crystal Barrier Highway, the radio control station of Streets (in the grounds of the R.S.L. Club) the Royal Flying Doctor Service is open for is a small monument topped by a piece of inspection daily. In front of thc entrance is a "ore Jroni the line oJload". Inscriptions on it "distance and direction disc" in memory of read "This monument conimemorates the Professor James MacDonald Holmes, foun- discovery oJ the Broken Hill ore body by dation member of the N.S.W. Council and Charles Rmp (I 846-1 907) September, 1888. friend of Dr John Flynn. Flynn began the The moiiirmetit faces Block 12, Ra,vp's first service in Queensland in 1Y28, and this base BROKEN HILL mininf hose which is 660 yards from this spot. was established in 1939. It is now connected Relow: Seldom is a monument as far from its ubject as Unveiled hy His Excellency Lt. Gen. Sir Erir to more than 400 "outposts" and each this broken column which was unveiled in Sturt Park by the Mayor, Alderman T. F. Hynes. on 2lst December. Woodward. K.C.M.G.. C.B., C.R.F., D.S.O., month about 5,000 radio messages are cx- 1913 to honour eight bandsmen (each listed by name) 19 September. 1958". Since this discovery, changed concerning medical matters. of thk "Titanic" which 20 months earlier had struck an well over 100 million tons of ore have been 0 Further afield, within a radius of less than tceherg and sunk in the Atlantic Ocean with the lasr of extracted. 100 miles, tourists can inspect: 1.63s he.. The inscription reflects lhe feelings evoked 111 those days by such tragedy and courilge-even though Acroys the road, at the entrance to the *a number of sheep stations, including IO dirtant. "Erectcd by rhr eillrrm of BroLrn Hill ov a railway station is a plaque featuring a map Corona (52 miles north) which was once mr~morrrrito Ilw heroic bunimcn o/ rhr rlronrrhip'Tiironir'. who plo,ving IO rbr cnd--'Ncarcr my Cod lo The?, Nearrr of Australia and showing the transcontinental owned by Sir Sidney Kidman, the Cattle IO ThhrP'--colmlj furrd cerfoin dculh. whihr wornm. rail route. It was "enluilrd by /he Righr Hun. King". The West Darling District of 45,000 chrldwn md thcir ./dlow~mmwere hrin.7 rmwrd /?om J. G. Gorton, Af.P., Prime Minister of Aus- square miles carries over 2 million sheep and Ihi, wrr;k of rhar ili-Jon"I vrsscl OBIhr mrul nf New- tralia on rVowmber 29, 1969, to conimemorate produces an annual wool clip worth more loundlond on Am-11 ISlh, 1912". the joining at Broken Hill of the standard than $8 million. puye railway line IinkinR the east and west * Silverton (16 miles northwest), a "ghost" roasts of Australia". town of the 1880's. and nearby Penrose Park, 0 Nearby, there is a bed of the strikingly with historic relics such as an early steam beautiful Sturt's desert pea--floral emhlem of cngine. Broken Hill. This low-growing wildflower * Menindee Lakes (70 miles southeast) for

BROKEN HILL Relow: Broken Hill base of Royal Flying Ductor Service (sec details in text abovel. below right: Many motoris15 arc unaware 01-a small stone nionument on the south side 01 the Barrier Highway ahout 20 miles west of Brnkcn HdI. It declarer "Thhr

b E

DECEMBER, 1972 PAGE 43 - Getting the “Feel” of Roads

As you read this page, your resulting thoughts continually build up visual SCALE MODELS HELP images in your brain. These images are the products of years of conscious and unconscious education, principally made BLIND CHILDREN possible by sight. A blind child, deprived of sight since birth, must be deliberately educated in the perspective and geography of the world around him before his education can hope for expansion towards the standard of the average sighted person. Maps and models help blind children to make sense of information gained from other faculties and external aids, and assist them to widen their knowledge of the unseen world around them. In July this year, the Department donated seven scale models of completed works to the Royal New South Wales Institution for Deaf and Blind Children at North Rocks. These models are now being used by students at the School for Blind Children as aids in learning spatial relationships, geographical concepts, as well as road and bridge technology. Such scale models have always been associated with learning about and seeing things which, otherwise, would not always be easy to visualise. They were previously displayed by the Department to let interested persons look into the future and understand how certain new road and bridge proposals would appear when completed. The models made available to the School included: * Tarban Creek Bridge-which forms part of the North Western Expressway. * Captain Cook Bridge, over George’s River-which forms part of the Southcrn Expressway. * Warringah Expressway-first section from Sydney Harbour Bridge to Cammeray. I * Bridge over Clarence River at c Harwood-and associated deviation of Pacific Highway around Maclean. * Bridge over Macquarie River at Dubbo. “ORIENTATION AND MOBILITY direct experiences. Blindness necessarily The Principal of the School recently restricts these experiences. forwarded the following report which Congenitally blind children often have Blind children, for example, often explains the fields and the manner in distorted concepts of spatial relationships believe streets go on indefinitely; they do which the models are used by the students, and verbalisms which can hide a lack of not have a useful concept of a city block;

PAGE 44 MAIN ROADS labelled in braillc. The location of Dubbo can be related to other markers rep- resenting, for example, Orange and Cobar. From the map the child also learns that Dubbo on the Central Western Plains is quite a long way from Sydney on the coast and consequently has a different climate to that of Sydney. There is a certain amount of in- formation like this that text books and the teacher can give, which is meaningful to a blind child, especially if one of the remaining senses is involved (e.g. temper- ature-climate). However, quite often the information is merely a visual concept and this is where the models become so valuablc. For Example, on the Dubbo Bridge model the children can feel the two bridges spanning the Macquarie River-one is low and narrow, the other much higher and wider. They ask why and learn that because the small old bridgc was too close to the river flats, which flooded in heavy rain and cut the approach roads to the bridge, the new one was built higher and longer so this would not happen. The bridge also needed to be larger to cope with the increased population and the increased number of thcy think all intersections are the same; that particular location. On the scale vehicles that would cross the bridge. they have no rcalisation of the heights of model he can feel the cars and buses on In one tactual closure, the child can buildings or the position of buildings. the varied road levels, the underpasses feel the two bridges, the river flats, the The child who has no vision must be and bridges, the train on the elevated water courses down to the river, the taught how spatial phenomena are related railway line and another standing at the willow trees along its banks and the river to onc another by tactile means such as station. He can compare the high and low itself. Because the model is correctly maps and models. rise buildings and feel their proximity to scaled he can conceive the comparative sizes of these things. Without a tactile Models, such as those given to the roads, trees and park areas. He now has School by the Departmcnt, enable the a far more accurate picture of that model it is not possible for a blind child child by touch to condense into one particular part of his environment. Next to do this realistically. Further more, by perceptual closure the meaning of a time he is in a similar situation it will he treating the whole model in sections the whole scene. By touching a model of an a far more realistic expericncc for him, children are able to build up a wealth of area he can cncompass widely separated as he will not be relying entirely on the information on thc town of Dubbo, spots in one perception. For example+ on verbal pictures of a sighted companion. which can be regarded as representative a mobility excursion or a class outing a He will have had a tactual experience of of other country towns in the area. child may have travelled by bus across the a similar situation, which is meaningful INDUSTRIAL ARTS Bradfield Highway to the City. On another to him and which is transferrable to the occasion he may have travelled by train new situation. Industrial Arts for the visually handi- via Milson’s Point to the City. He has had capped is not only concerned with SOCIAL SCIENCE two cxpcriences and built up some con- practical workshop techniques, but also cepts from idormation his teacher has The models donated by the Department with the technology of everyday life. given him and from his remaining senses. are used in the classroom in conjunction Road and bridge construction together Perhaps his teacher has told him that with foam rubber maps, which are one of with traffic flow and control are a part from the train window, while thc train is the basic aids used by blind children in of this technology. stopped at Milson’s Point station, it is learning geographical concepts. When a For the visual handicapped a word possible to see cars and buses on the lesson is bcing given on New South Wales description has little meaning. However, Bradfield Highway, which is lower than the children learn to find coastal areas, the model of the bridge over Tarban the trainline. From such comments, the plains, mountains, rivers, citics and towns, Creek provides a tangible illustration of child builds up a mental picture of his on their foam maps. traffic movement on an expressway. surroundings but it is probably in- A specific example could be Dubbo on A blind person may not be able to accurate. the Macquarie River. The child feels for make practical use of the knowledge However, if it is possible to provide the the recess in the foam which represents gained, but he will be able to understaiid child with a model of the area (such as the river and which is labelled with the the world around him in a better way. the Warringah Expressway model) then name in braille. The child then locates a His conversation with his sighted peers his concepts can become a real percept of marker denoting the town, which is also will thus be on equal terms.”

PAGE 45 DECEMBER, 1972 WESTERN DISTRIBUTOR

Completion of Stage 1 of the first section At a later date, the Distributor will be changes, copies of the publication were of the Western Distributor from Sydney continued southwards to an interchange supplied to the press for reproduction and Harbour Bridge to Day Street was at Ultimo, from which the Southern and were also made available to Motor marked by the opening to traffic of the Western Expressways will commence. Registry offices and N.R.M.A. offices at southbound roadway on 2nd September, Further adjustments to its links with the a number of city and suburban locations. 1972. Stage 2 was completed soon after city street system (e.g. at Margaret The leaflet includes a map of the city and the northbound carriageway was Street) will then be made. area from George to Day Streets and brought into use on 30th September, An article giving construction details from the toll plaza to Druitt Street. It 1972. about the Distributor appeared in the clearly shows the direction of trailic flow This section of the Western Distributor September 1970 issue of “Main Roads” in streets adjacent to the Distributor and was brought into full operation on (Vol. 36 No. 1, pp 2-6) and is available indicates any restricted turning tnove- 20th December, 1972 when Stage 3 on request as a separate reprint. ments. The leaflet describes a novel was finished and the connecting ramp “colour code sign system’’ which has from Pyrmont Bridge to the Distributor’s been introduced to assist southbound northbound carriageway (via Day Street) ***it*** motorists on Sydney Harbour Bridge to was opened. select the most appropriate lane and As can be seen from the aerial photo- thereby pass through the correct toll graph above, the Distributor is already an With the completion of each stage of booth. To do this, drivers simply I‘ollow attractive, integral part of the city scene. the Western Distributor and its opening one of three colours according to their It should ease traffic conditions in to traffic, there has been a re-arrangement destination. Thus, motorists wishing to Sydney’s crowded streets by providing of the traffic flow in some nearby city travel east via Grosvenor Street follow separate, more direct access between streets. Consequently, the Department the blue signs displaycd on the Bridge and Sydney Harbour Bridge and the southern published a 4-page colour leaflet as a above the toll booths. For Day Street and end of the City. By this means, north- guide to motorists and distributed copies York Street the colours to follow are south traffic is being directed away from to drivers of city-bound vehicles at the green and orange respectively. the busy shopping and commercial Sydney Harbour Bridge toll gates over a These arrangements are still in thoroughfares such as Pitt, George and 12-hour period on 31st August, 1972, just operation and any person wishing to York Streets. The western business area prior to the opening of Stage 1. obtain a copy of this helpful leaflet needs of the City is also bypassed as the To ensure that the maximum number simply to contact the Public Relations Distributor crosses above Clarence, Kent, of motorists were provided with the Section, Head Office, by telephone, and a Napoleon, Sussex and Erskine Streets. necessary knowledge about direction copy will be posted out.

PAGE 46 MAIN ROADS Right: New bridge om the exwyto link Gladstorn Awnve and Mt St Tho- Boulewrde, Fig Tree.

Below: Looking pan the wezant route of Glsdnone Avenue lat the temwrary southen "end" of the exparrwev) to the new briJge . which will carry Masters Road, Fig Tree, over the next section of the expressw~y. bc- I

To be free of any at-grade intersections, the Southern Expressway must cross under or over a number of important roads and railway lines when it is extended between Gladstone Avenue, Fig Tree and Northcliffe Drive, Berkeley. Illustrated here are some of the thirteen major bridge works required on this three mile section. The different, attractive designs add a touch of distinction to the basic functional value of these structures. Although the bridge sites may now seem strangely isolated and lacking in any unifying link, on the completion of this section of the expressway, they will become an integral part of it and will provide for the smooth flow of the large volumes of cross traffic in this area.

Left: Berkeley Road, Unanderra. will C~OII the expressway on this slim structure.

Abow centre: Conrnuaion of the bridge to mrry the exwerrway over the Main South Coan Railway line at Fig Tree. i Ri#ut: Theos new briirwill cdrry the expaway OWthe Australian Iron and Steel i Compnfr railway line and accm road - ram the pmpoad intereharrpe at Five Islands bd,Vruncbm. Barrier Hi

Black Crow

A Better Way West

For millions of people who live in the crowded coastal corridor of our State, there is a different world waiting for them out West. Visitors now have in the Barrier Highway a fast, comfortable, distance-defeating driveway to discovery. Gone are the drawbacks and delays of yesterday's dusty, corrugated conditions. Today there is a bitumen road from the beginning (at Nyngan) to the border (at Cockburn) - and on to Adelaide. too. Thesights are not as obvious nor as frequent as in the east but, for those who succumb to the lure of the outback, there is always plenty to see. (as outlined in the article on page 41 I. The dangers of western travel have now been diminished, if not entirely eliminated, but a sense of adventure is still a vital part of every first visit. A journey west can bed wonderful way to observe wildlife in its natural surroundings, to savour the vastness of our State's varied landscape and to fossick for history in sunburnt townships at the opposite end of New South Wales. Trains may "take the tension out of travel" but, for most of us. there is no substitute for the feeling 01 freedom engendered by sitting behind the wheel of our ow11car and heading away from city congestion. And, as there is no substitute for seeing things first hand. there is no better way to see the West than by road. That means the Barrier Highway - now reconstructed and sealed all the way. yav t- iqhlights

Minehead at Broken Hill Old steam engine af Cobar

rt Improvements to the Mitchell Highway between Bathurst and Wellington

smoolhing outthe twists

Reconstruction of the Mitchell Highway at 8 miles north of Molong includes widening the pavement and improving the alignment (above). It also involves building a bigger bridge over the Bell River at Claremont (at far left-bottom), of which more details are given on page 51.

Recently completed sections, such as at 25 miles west of Bathurst near Shadforth (at left and far left-top), mean that Mitchell Highway motorists are getting easier curves and more miles of pleasant driving. RtPUKl UN ROAD AND BRIDGE WORKS AROUND THE STATE

MITCHELL HIGHWAY Completion of Sealing On 6th November, 1972 another milestone in the history of road construction in New this 21-mile section of the Highway was building a 3-span prestressed and rein- South Wales was passed-with the com- completed in 1968. forced concrete bridge, 170 feet long, pletion of the bituminous surfacing of the Reconstruction and bituminous sur- over Molong Creek at Larras Lee. The Mitchell Highway. The 85-mile section facing was then commenced on the contract price is $78,703.80 and the from Bourke to the border with Queensland section from 20 miles north of Bourke to bridge should be completed by mid-1973. is now sealed throughout, following the Engonnia, a distance of approximately * Less than a mile to the north at Bell completion of the last 5-mile section 42 miles. River, Claremont a 3-span, 172 feet long, approximately 2.5 to 7.5 miles south of Since 1965 a length of approximately steel girder and reinforced concrete deck Engonnia (i.e. 25 to 30 miles south of the 67 miles of reconstruction and bituminous bridge has been built for the Department border). surfacing has been completed north of by Ermani Constructions Pty Ltd at a A A Q Bourke at an average rate of almost 9.5 contract price of $1 16,347. miles per year and at a total cost of * About five miles further on, the Bcll In mid-I958 the only bitumen surfaced approximately $3.75 million. River again crosses the Highway and pavement on the whole length of the If it was easy to translate into monetary here, at Three Rivers, A. Cipolla and Co. Mitchell Highway from Nyngan to the terms the savings due to shorter Pty Ltd are undertaking the construction Queensland border at Barringun was a travelling times, less “wear and tear” on of another new bridge. The 6-span pre- 13-mile section at Bourke (from 3 miles vehicles and less strain on drivers, the stressed and reinforced concrete structure, south to 10 miles north), together with cost of these roadworks would just as will be 362 feet in length. It will be short lcngths in the towns of Nyngan, easily be recognised as a good investment located on a short deviation of the Coolabah, Byrock, Engonnia and for the people of New South Wales and Highway and will be situated about 600 Barringun. The length of the road with- a bonus for the interstate travellers using yards downstream from the existing out bituminous surfacing then totalled this route. narrow timber bridge. Completion is almost 200 miles. Earlier ‘%toin Rondr” arfirlcs on lhe norlhern secfinit expected in June, 1973 at a cost of of the Mirihrll Hichwoy include: Between 1958 and 1961 the Depart- * “Borewnrer and hilurnrn on road Io Boarringuir” in $1 57,743. September, 1965 issue (Vol. 31, No. I, pn.em 14-15), ment’s works organisation at Bourke * ‘‘Npgon io Barringun-Rilrmen sicrfaeinp on Mirrhcll * In January, 1973 a fourth contract is extended the bitumen sealing of the Hkhwas” in Scplemher, 1964 irsse (Vol. 30, No. 1. expected to be Ict for the construction of Highway 16 miles by increasing the a new bridge over Molong Creek, 1 .S miles lengths to 14 miles south and 15 miles south of Larras Lee, to replace the old north of Bourke. * * * Angus Bridge. The new structure will be In 1961 the Department established a a 3-span composite steel girder and rein- Works Office at Nyngan and efforts were Bridges north of Molong forced concrete bridge, 135 feet long. concentrated on the completion of pave- A 6-mile section of the Mitchell Highway All four bridges provide a width of ment sealing between Nyngan and north of Molong is currently the centre of 28 feet between kerbs. Bourke. This target had been achieved a concentrated burst of hridge-bnilding. In conjunction with the construction by 1966, the rate of progress averaging No record breakers, these four bridges of these four bridges, the Department is 20.5 miles of road reconstruction and are nevertheless typical of the hundrcds continuing with the reconstruction and bituminous surfacing per year. completed each year by the Department- widening of the Mitchell Highway to North of Bourke the sealed pavement to improve the short crossings over the provide a 24 feet wide pavement and 44 was extended a further 5 miles during multitude of waterways which dissect the feet wide formation on the IO-mile 1961-62. In 1965 reconstruction work State’s Main Roads System. section from Copper Hill to Three Rivers was commenced on the black soil areas * At 7 miles north of Molong, Emoh (between 3.9 and 13.9 miles north of between Engonnia and Barringun and Ruo Court Pty Ltd of Narrabri are Molong).

DECEMBER, 1972 PAGE 51 State Highway on which bituminous The approaches to the bridge will be surfacing will have been completed in a constructed by the Department's own 12-month period. forces. It is worth noting that all of these highways form part of important interstate routes. The Barrier Highway is a section New Bridge south njMoree of National Route So. 32 which runs On 9th November, 1972, a contract from Sydney to Adelaide, and the Mitchell was let for the construction of a new Highway forms the major part of National bridge over Courallie Creek on the Route No. 71 which connects Nyngan (on Newell Highway, 16 miles south of SNOWY MOUNTAINS National Route No. 32) with Cullamulla Moree. in Queensland. The Snowy Mountains The new bridge will be an 8-span HIGHWAY Highway has been numbered National reinforced concrete structure, 280 feet in Route No. 18 and lies at the eastern end length, and will be situated on a new Final seding almost .finished of a route which extends from the south deviation of the Highway. It will replace coast near Bega (on the Prince's Highway) a narrow timber structure known as Reconstruction and bituminous surfacing to Adelaide (also on the Prince's Highway) Gurley Bridge which is on a poor align- on the last unsealed section of the Snowy via Cooma, Wagga Wagga, Hay, Mildura ment. Designed by the Department, the Mountains Highway should be completed (Victoria) and Renmark (South Australia). new bridge will measure 29 feet between by mid-1973. The 600-mile long Newell Highway covers kerbs. Over half of the section between about two-thirds of the inland inter- The successful tenderer was A. Cipolla Kiandra and Rules Point (13.6 miles capital link between Melbourne and and Co. Pty Ltd of Sydncy. The contract west of Kiandra) has been sealed and the Brisbane, which is formally known as price is $I 14,780.00 and the time for remaining 6.6 miles should be finished by National Route No. 39 from near Seymour completion of the bridge is 70 weeks. about April 1973. (Victoria) to Goondiwindi (Queensland). Between Rules Point and Inspiration Point (29.4 miles west of Kiandra) 4 This aspect highlights the fact that milcs at thc western end have been prime increased traffic, including many inter- sealed and work on the remaining 12 state tourists, will ''Follow the bitumen" miles should be completed by next June. along these routes and will bring better Workers in this area have to contend business prospects and aid the development with snowfalls and intensely cold of many country areas of the State. PRINCE'S HIGHWAJ' conditions, and roadworks have to cease An arrlrlc rntirlcd "Ncwcil Hiph~"~-Rcronsrnrrtion Tocrrmwa! to Ardierhan and Norrnhri IO Morcc" uppmwd completely during the mid-winter months. io rhc March. 1966 iwic 01 "Main Roads" (Vol. 31. Boydtown-Kiah h'o. 3, pp Rl-93). The Prince3 Highway has been shortened by almost two miles with the New Bridge at Narrabri opening of a $1.25 million bridge and deviation south of Eden. The deviation, from 4.9 to 8.1 miles south of Eden, was At Narrabri, construction is under way opened to traffic on 28th Seplember, for the Department on new bridge over a 1972. the Namoi River. NEWELL HIGHWAY The new road replaced a narrow, The bridge, a 5-span prestressed con- winding section of the Highway with poor crete structure 325 fect in length, will sight distance and provides much safer Full length sealing nears replace a narrow timber beam bridge travelling conditions between Boydtown which was built in 1914. Designed by the completion and Kiah. It includes a 482 feet long Department, the new bridge will be bridge over Whelan's Swamp amd 2.5 On the Coonabarabran-Narrabri Section located on deviation of the Highway on a miles of climbing lanes to accommodate of the Newell Highway, bitumen sealing an improved alignment. It will measure slow-moving traffic--especially heavy was completed to the primed stage in 28 feet between kerbs and will carry two trucks associated with the local timber January, 1972. The final seal should be eight-feet wide footways. Provision has trade. put down by March, 1973. been made for duplication of the bridge Earlicr rcfcrcnrrs to Ihis wrk nppmrrd in tho Merrli. The only section of the Highway when traffic conditions warrant it. 1972 irrrrc (Vol. 37 No. 3. p 94) md rhr hnr. 1972 iww which now remains unsealed is from The bridge has been designed with (Vol. 37. No. 4, pp 114.1 15) of "Motn Roadr". 43.5 miles north of Moree to Boggabilla single column piers similar to those in (72 miles north of Moree), near the the approach spans of the bridge over the Big Bridge for Bega Queensland border. Macquarie River at Dubbo. In June, 1972 Reconstruction work on this 28.5 mile a contract for construction of the bridge Construction on the first stage of a by- long section is well advanced and was let to Firth Civil Constructions Pty pass at Bega is under way and this flood- should be finished late in 1973. At that Ltd of Tamworth and the time for com- free route will include the provision of a time the Newell Highway will join the pletion is 60 weeks. The contract price of new bridge over the Bega River and its Barrier, Mitchell and Snowy Mountains $195,195.00 includes the demolition of overflow channel. Highways (see pages 34, 51 and 53 the existing timber structure on com- The 23-span bridge, a prestressed and respectively) and will become the fourth pletion of the new bridge. reinforced concrete structure 2,046 feet in

PAGE 52 MAlh ROADS FRR AND

length, will be the sixth longest bridge in the State, behind such giants as: * Sydney Harbour Bridge (3,770 feet).- see details in March and June, 1972 issues of “Main Roads” (Vol. 37, No. 3, pp 82-87 and No. 4, pp 122-126). * the bridge under construction at Gundagai (3.750 feet)-see details on next page, Artist’s impression of wwbridge to carry Pacific Highway over Wilson River at Telegraph * the bridge under construction at Point. Camden (3,380 feet)-see details on page 58, * , north of Newcastle (3,358 feet)-see details in March, 1972 issue of “Main Roads” (Vol. 37, No. 3, pp 66-69), * the bridge over the Clarence River at Harwood-see details in September, 1966 issue of “Main Roads” (Vol. 32, NO. I, pp 2-9). The new bridge will be located 600 feet upstream from the existing bridge, and as the Bega River is subject to severe flooding, it has been designed by the OXLEY HIGHWAY PACIFIC HIGHWAY Department to provide a clearance of four feet above the highest rccorded Rood New Bridge at Ellenborough New Bridge at Telegraph -which occurred during February, 1971. Point The northern approaches will include an Travelling conditions on the Oxley High- way will be considerably improved by the improved access to Carp Street, Bega Work is underway on a new bridge over provision of a new bridge over the while pedestrian access from North Bega the Wilson River at Telegraph Point has been catered for by the provision of a Ellenborough River on the Oxley High- (11.5 miles north or Port Macquarie) to footway on the downstream side. A way, west of Wauchope. In October, replace a narrow wooden bridge on poor 1972 the Department accepted a tender stairway leading from the footway will alignment and to eliminate a railway level of $234,654 from Transbridge Pty Ltd give access to the western end of Carp crossing. Located in a deviation of the Street. A low concrete parapet capped for thc construction of a 5-span, pre- Pacific Highway north of Port Mac- stressed concrete structure, 330 ft in with two steel rails will separate the quarie, this new bridge will be a Rood- length and 28 feet between kerbs. pedestrian footway from the road free, 15-span prestressed and reinforced carriageway. The existing old timber bridge at this concrete structure, 1,836 feet long (see site was damaged by a timber jinker and artist’s impression above). On 23rd August, 1972 a tender of has had to be supported by “Bailey” Construction is being undertaken for $1,173,581 for the construction of the bridging which restricts the passage of bridge was accepted by the Department the Department by Pearson Bridge traffic. from Peter Verheul Pty Ltd. To reduce (N.S.W.) Pty Ltd at a contract price of Designed by the Department, the new $1,432,000 and work should be finished the construction time, the Department bridge will be located on an improved by about mid-1974. has supplied the materials for the steel alignment about 700 feet upstream from Construction of the bridge is part of a piles on which the bridge will be founded. the present bridge. It will have a two reet multi-million dollar programme to be The bridge should be available to wide safety kerb on each side and will be undertaken in the area over the next few traffic in December, 1974, and the total very similar in design to the recently years, which, when completed, will con- cost, including approaches, will be in the completed bridge over Stony Creek on siderably improve travelling conditions order of $2.5 million. the same Highway (see photograph in on this major interstate artery. article on Oxley Highway reconstruction -in “Main Roads,” June, 1971, Vol. 36, No. 4, p. 117).

DECEMBER, 1972 PAGE 53 FRR AND PRESENT ROUTE - - PROPOSEDNEW OF HUME HIGHWAY BRIDGE

MUR RUMBIDG EE

HUME HIGHWAY New Bridge at Gundagai The Department has commenced con- struction of the foundations for a new bridge over the Murrumbidgee River at Gundagai (see illustration at right). Measuring 3,750 feet in length, the bridge will be a 27-span composite steel SHERIDAN STRE and concrete twin girder structure with 3 spans over the main river channel and 24 spans over the flood plain. In view of the PRESENT ROUTE OF HUME HIGHWA high velocity floods which cross the plain provision has been made in the design for single column "T" shaped piers. PROPOSED NEW ROUTE OF HIGHWAY ' Designed by the Department, the new structure will be very similar to the bridge now under construction over the Nepean River at Camden. On completion it will Scale model of proposed deviation of Hume Higlrn or' uird IIVIV hrir(?.r at Giitrda,~al!iwkin~ displace the bridge at Camden as the south. This model is on display at the Departmetit's Head 0ffirr, Third Fto~w. second longest road bridge in New South Wales and the longest ever built by the Department. Twin Bridges near Mittagong LAKE ILLAWARRA The new bridge will be located on a CROSSING M'1DENlli:D deviation of the Hume Highway west of Tenders were called in November, AT WINDANG the town. This 4.4 mile long deviation 1972 for the construction of twin bridges will provide motorway conditions and over Paddys River on the Hume Highway, will involve the construction of 15 lane 26.5 miles south of Mittagong. Improvements to traffic facilities on the miles of roadway and nine other bridges. Each bridge will be a 3-span structure, bridge over the entrance to Lake Illawarra Although the new highway route will pass 225 feet long and 28 feet between kerbs. at Windang were completed with the around Gundagai, access to the town They will be of prestressed concrete and opening of the northbound carriageway will be available both from the northern reinforced concrete construction and on 22nd September, 1972. The end of the deviation, at Sheridan Street will replace an old narrow timber southbound carriageway became fully (where there will be an interchange) and structure. operational on 22nd December, 1971. from South Gundagai. The narrow The old bridge was a narrow timber wrought iron Prince Alfred Bridge built The design for these bridges is in structure which frequently caused delays in 1866 will remain for use by local accordance with the Department's plan to traffic using the Shellharbour-Port traffic. to provide dual carriageways on the Kembla Road (Main Road No. 522) in Estimated cost of the new bridge and Hume Highway as soon as practicable. periods of peak traffic flow. deviation is approximately $5 million, The northbound bridge will be built To overcome the problem, a new two- and they are expected to be completed first and will carry two-way traffic while lane concrete structure, with one footway, about the end of 1975. the existing timber bridge is demolished was erected alongside the existing timber The foundation piles for the main and the second bridge for southbound bridge. When this was completed, all bridge are at present being constructed by traffic is constructed. traffic was diverted to the new structure the Department's own forces and the while replacement of the superstructure remainder of the main bridge and the A feature of the bridges will be round of the old bridge was in progress. These associated bridges will be constructed by single column piers designed to blend the bridgeworks were carried out for the contract. Construction of the roadworks new structures with the natural Department by Peter Verheul Pty Ltd. will also be undertaken by the Depart- surroundings, which will in turn be en- Now combined as a single unit, the hanced by the establishment of new ment's own forces and progress on them a composite structure is 983 feet long with will be programmed to fit in with the work Remembrance Driveway plantation near- a four-lane divided carriageway and two on the bridges. It is expected that tenders by* footways each five feet wide. for construction of the piers and super- The approaches to the bridges will be An orrlnl photocraph to'.cn duurlns conrtrurtlon 01" the structure will invited by mid-1973, new SI~UCIUIC approrrd on the fmnr MYII OJ the Srprem(ur, be constructed by the Department. 1)71 bWc 0f"Mnh 8QRdJ" (I'd, 31, NO. I).

PAOE 54 MAIN ROADS This extension of sealed highway will to Sydney, to ask what the value was, and undoubtedly be a boon to the people of whether it was worth going on with as a FRR AND Walgett and to the growing number of mining venture.’ The reply was ‘that it tourists driving north to try their luck at would be worth 701- per ton as road metal the opal-mining centre of Lightning in Sydney’ ”. Ridge. Seldom have roadworks offered such Lightning Ridg.e has a claim to fame as possibilities for profit! For dedicated the world’s only “black opal” field. To engineers there has always been a certain distinguish these opals from lighter types, inner sense of satisfaction in undertaking the term “black” was chosen to emphasise road and bridge building, but it is not CASTLEREAGH their darker background tones. However, often that such rich rewards have come the name is a little misleading as it within reach of the early “gravel-getters”. HIGHWAY suggests these stones might not be as These pioneers worked in all corners of bright or attractive as others, whereas our State practising the valuable but Still more bitumen they are equally “ablaze with flashes of virtually unacknowledged art of tracing liquid flame”. and transporting the best type of road- making materials. For a number of years, the Department From a road building view point, it is has been actively working on the interesting to note two of the stories It seems certain that by 1891 opals had progressive bituminous sealing of thc associated with thc finding of the first been found in the Lightning Ridge locality, but it was not until about 1903 Castlereagh Highway. On 22nd Septem- opals in this area. The suggestion by T. ber, 1972, work was completed on the Cosgrove in the February, 1970 newsletter that a small syndicate was set up to section from eight miles north of Walgett of the Royal Australian Historical Society systematically mine the area. This was to the Lightning Ridge turn-off. The cost (p. 8) that “Thisfield was discovered about but the beginning and, although the more of this 40.4 miles long section has bccn 1912 when a few road-makers, looking for hectic days have passed, Lightning Ridge is still a magnet attracting many people approximately $2.5 million. Its gravel, picked up handfuls of this beautiful eager to see the place where opals were completion means that the Castlereagh stone” conflicts with the following claim Highway now has a sealed surface by the late S. Lloyd in “The Lightning formed and are found. To visitors and northwards from Gilgandra through Ridge Book” (1968-p. 89). “The first miners alike, the sealing of this section of Coonamblc and Walgett to the junction evidence of anyone taking a mineral interest the Castlereagh Highway will make getting with Main Road No. 426, which leads to in the Lightning Ridge locality is that of there less arduous.. Lightning Ridge. Bituminous surfacing is Robert Moore, newly appointed manager now being continued towards the of Muggarie Run (Angledool) Station. In Goodooga turn-off and Angledool, near 1873-74 he ‘sent a hatjiul of the pretty the Queensland border. stones collected from the Mebea Ridges,

INCOME AND EXPENDITURE ACCOUNT SYDNEY HARBOUR BRIDGE ACCOUNT FOR THE YEAR ENDED 30TH JUNE, ,972

~~~ ~ Income 1971-72 1970-7 I s s Road tolls 4,707,302 4,518.708 Railway tolls 272,465 299,992 Omntbiis tolls 2 1,723 26,151 Nct rcnlr. from properlies ____167,722 ~___ 170,700 -Total Income 5,169,212 5,015,551 Fxpenditiire 1971-72 1970-71

~ -- ”.P P Maintenance, lighting and cleaning of bridge and approaches 803,248 sh4.345 Provision of traffic facilities 292,276 161, I24 Cost of collecting road tolls 507.6 14 5 16,030 Improvements and alterations to toll gates and archways 7.03 1 32,143 Administrative expenses 175,443 81,346 Loan charges-State loans 1,251.890 1,229,660 Loan charges-Borrowings under Section 42A of the Main Roads Act, 1921 909, I44 923,576 Tntal Expenditure 3,946,646 3,508,224 Excess of income over expenditure transferred to Appropriation Account 1,222.566 1,507,327 ------$5,169,212 $5,015,551

DECEMBER, 1972 PAGE 55 Statement of Receipts

FOR YEAR ENDED

- County of Country Commonwealth Total RECEIPTS Cumberland Fund Fund Fund $ $ $ $

Motor vehiclc taxation ...... 13.83 1,864 42, 118,337 .... 55,951:1.201

Charges on commercial vehicles under the Road Maintenance (Contribution) Act, 1958 ...... 3,537,392 14,149,567 .... 17,686,959

Levy upon Councils in accordance with Section 11 of the Main Roads Act. 1924 ...... 5,890,275 ...... s,x90,275

State Government loans-Repayable ...... 1,000,000 I,000,000 .... 2,000.000

Loan borrowings under Section 42~of the Main Roads Act, 1924 6,300,000 500,000 .... 6,800,OM)

Contributions by Councils towards maintenance and construction

of Main and Secondary Roads ...... I. .. 343,459 301,841 .... 645.300

Contributions by other departments and bodies towards maintenance and construction of Main and Secondary Roads .. .. 265,089 510,686 .... 775,775

Commonwealth/State Government grants-

Resloration of flood damage ...... t...... Relief of unemployment ...... 655.000 .... 655,000

Sydney Harbour Bridge Account for expressway approaches . . 56,883 ...... 56,883

Commonwealth Aid Roads Act, 1969- Urban arterial roads-Schedule 2 ...... 39,060,000 .... Rural arterial roads-Schedule 3 ...... 12.4 10,000 ....

Other rural roads-Schedule 4 . , ...... I...... 3,326,617 .... Planning and research-Schedule 5 ...... I, 120,000 55,916.617

Other , ...... 836,413 183,896 .... 1,020,309

Total Receipts $32,061,375 $59,419,327 $55,916,617 $147,397,319

PAGE 56 MAIN ROADS

_____~ and Payments

30TI-I JUNE 1972

County of Country Commonwealth Total PAYMENTS Cumberland Fund Fund Fund - $ s $ s

Construction and reconstruction of roads and bridges . . .. 9,259,182 27,094, I65 45,913,855 82,267,202

Construction and maintenance of unclassified roads in the unin- corporated area of thc Western Division ...... 195,783 195,783

Maintenance and minor improvement of roads and bridges .. 5,430,991 20,933,317 .... 26,364,308

Restoration of flood damage ...... 475.456 .... 475,456

Land acquisition ...... 6,063,013 I, 134,874 7,918,528 15,116,415

Purchase of land and buildings for works operations . . .. 448, I20 436,448 .... 884,568

Purchase of land and buildings for administration ...... 176,802 2 12,450 .... 389,252

Administrative expenses ...... 3,775,630 5,637,843 .... 9,413,473

Planning and research ...... 1,741,592 1,741,592

State Treasury loans- Sinking Fund payments ...... 15.470 I 72.730 .... 188,200 Interest, exchange, management and flotation expenses . . .. 193,710 922,270 .... 1, I 15,980

State Treasury-Rcpaymcnt of temporary advance ...... ion,ono 100.000 .. 200,0(10

Loan borrowings under Section 42~of the Main Roads Act, 1924- Repayment of principal ...... 171,118 177,466 .... 348,584 Interest ...... 671,819 1,086,255 .... 1,758.074

Other ...... 315,030 ______547,288 ______.... 862.318 26,620,885 58,930.562 55,769,758 141,321,205

Transfers to reserve for loan repayments ...... 145,425 163,763 309,188

Net transactions of operating and suspense accounts . . .. 662,736 609,476 ______.... 1,272,212

Total Payments . . .. ,. .I I. $27,429,046 $59,703,801 $55,169,758 $142,902,605

DECEMBER, 1972 PAGE 57 The new hridge is U 2-lune, 3,380 feet long strrtcture and will form port of U 5-mik deviation of the Hume Highway which will allow through traffic to by-pass thr towns of Narellan and Camden. This cler~iotionwill he linked with the 9.75 mile section of the South Western Expressway now nn& construction hetween Cross Rouds (near Liverpool) and Muryfelds (near Cumphdltuwn)-hy U dual curriage- way rod from Cumphellrown to Narellan. Thp new hridgc will cross the Nepean River and its flood plain approximately one niilij ripstreom of the existing low Irwl hridgr. On eompleliun the hridge will curry thc Hwme Highway across its lust mujor flood bcirricv, with U minimum elcaranee of 3 fivt ohow the liwl of the highest recorded .flood-in Frbrrtury, 1873.

SELECTING THE TYPE OF STRUCTURE

The first part of thh article gives brief In considering various types of struc- UWhilst the bridge site is only 21 miles outlines of thc considerutions behind two tures, the following observations were from the coast it is considered that the wry important choices-one relating to the made : atmosphere is substantially non- selection of the type of hridp structure OThe presence of sound rock at an corrosive. Thercfore there is little und the other relating to the method hy average depth of 65 ft below natural dinerence in the relative merits of steel which prrwressing of the suprrstrurture surface pointed to the use of contin- or concrete bridges in terms of future would he currii4 out. uous spans with their inherent material maintenance. As well as exumples of the ways in economy, better appearance, and im- In order to compare the relative which thought precedes action in hridge proved riding qualities. Cast-in-place economies of continuous span stnictures construction, they are an indicution of the concrete piles to the rock were con- constructed from steel, reinforced concrete immensc amount of planning and investi- sidered to be the most suitable foun- or prestressed concrete, and with various gation which is undertaken by Depurt- dation for this type of structure. span arrangements in each case. a number mmtul officers to ensure that its OThe permanent well-defined river of structure types were investigaled and ronvtrirction methods are U blend of the channel required a minimum span of preliminary estimates prepared. most economical and the most efficient. 130 ft length. Therefore the alternatives In all of these preliminary investigations would have been to use constant span the concept of the design of the whole of *** lengths of 130 ft or more for the full the bridge as a single entity was adopted, length of the bridge or to use shorter rather than the approach of first selecting The second port gives detuils of the approach spans with the 130-ft span a superstructure type on economic fabrication and erection of the steel girders over the river channel. grounds and not proceeding with the und prcstressing of the suprrstrurture hy controlled lowering ut the supports This inforniution is supplementary to that already published in the June, 191I issue of "Main Rouds" (Vol. 36, No. 4, pp. 98-103) rmder the title "Design of New Rridgr ovcr Nepean River ut Camden".

***

MAIN ROADS 1.15 detailed design of the substructure (such I Ti-I as the number of piles, etc.) until later. Prestressed Concrete Box Girder As the site was admirably suited to the operation of the Department’s Benoto 1.10 machine in boring for the foundations, COST the use of 34-in diameter cast-in-place I 1 Reinforced Concrete Box Girder 1 I / i RATIO piles became one of the major consider- ations during the design. The vertical load 1.05 capacity for this size of pile at this site was assessed at 350 tons. This figure was based on proof load tests on similar piles I 1.00 at Stockton Bridge over the North r hi I I\ I I Channel of the Hunter River, north of :omposite Steel Open Trough Girder ./- Newcastle (see March, 1972 issue of 1 with Composite Concrete Deck “Main Roads”, Vol. 37, No. 3, pp. 66-69) I -.,TI-i-I I I..- 3.95 and at the bridge over Tuggerah Lake at The Entrancc (see brief details in March, 1969 issue of “Main Roads“, Vol. 34, No. 70 80 90 100 110 120 130 140 150 160 3, p. 87-and front cover of Junc, 1969 issue, Vol. 34, No. 4). LENGTH OF SPANS (FT) At least two 34-in diameter pilcs per BRIDGE COST COMPARISON pier were required for the span at thc main channel. Hence it was decided for Bridge over Nepean River at Camden the initial inwstigufions to adopt two 34-in diameter piles (each with a load capacity of 350 tons) for the piers. which all span lengths were less than The cost comparisons showed the total Subsequent work showed that two piles 130 ft had to be adjusted to incorporate cost of the steel open trough girder with per pier gave the most satisfactory a 130-ft main channel span. a composite concrete deck to he 2 per cent less than that for the reinforced solution whcn rrll factors were considered. J Reinforced Concrete Box Girder. concrete box girder and 3 per cent less To enable cost comparisons for various Previous cost studies for the bridge types of bridges, preliminary designs were over Tuggerah Lake at The Entrance than that for the prestressed concrete developed to the stage where thc section (a structure of similar type and pro- box girder. sizes, pier sizes, and pile loads wcrc portions) had indicated that the eco- The cost comparisons are illustrated determined. The scope of these investi- nomic limit to the span length was on the above graph. Bearing in mind that, at best, the gations was quickly narrowed down to 85 ft. estimatcs could only be expected to be three types of bridges, as follows: An estimate was prepared for a OSteeI Plate Open Trough Girdcr with bridge proposal with spans of 85 ft within *5 per cent, the percentage Composite Concretc Deck. together with a main channel span of differences in total cost noted above were not sufficient to favour outright one bridge A comparison between a single 130 ft. trough, a two-trough, and a threc- The pile load under the 85-ft spans type over the others. trough cross section showed that the was 305 tons. Further consideration was necessary, therefore, to enable a choice of structure two-trough cross section was the most U Prrsfressed Concrete Box Girder. economical arrangement for a 38-ft 8-in type to be made. One important point Prestressed concrete box girder was that the use of a constant 130-ft deck width. This is in line with the bridges of constant span lengths of findings of Johnston and Mattock (in span arrangement had the greatest po- 90, I IO, 130, and 150 ft, were investi- tential for economy in that it allowed R paper entitled “Lateral Distribution gated, the 90- and 1 IO-ft span cases of Load in Composite Box Girder the maximum amount of repetition in also being adjusted for the 130-ft main design, fabrication, and erection. Bridges” published in Highway Re- channel span. search Record No. 167, 1967) that For the reinforced concrete box girder the most economical number of trough The cost comparisons indicated general type, the limit to the spans was approxi- (box’) girders for this type of super- optimum span lcngths for this site of mately 85 ft and constant 130-ft spans structure is equal to the number of 90 ft for the steel open trough girder, over the whole length of bridge were design traffic lanes. with a composite concrete dcck, and thus not practicable. For the prestressed Preliminary design calculations were 105 ft for the prestressed concrete box concrete box girder type, constant 130-ft made for continuous superstructures of girder. However, when the requirement spans resulted in a maximum pile load equal spans, with allowance for of the 130-ft main channel span was of 400 tons, which was in excess of the moment redistribution between the taken into account, the cost for the steel 350 tons accepted as a maximum. More supports and mid-span, by means of open trough girder with composite con- than two piles per pier would thus have controlled lowering at the supports. crete deck remained at a relatively con- been required. The span lengths considered ranged stant minimum over the range of 90 to On these grounds, therefore, the steel from 70 to 160 ft. However, as 130 ft. On the other hand the cost for open trough girder with a composite mentioned above, the main channel the prestressed concrete box girder was concrete deck at constant 1304 spans required a minimum span of 130 ft at a minimum in the range of 110 to was chosen. The maximum pile load for and, consequently, those estimates in 130 ft. this structure was 325 tons.

PAGE 59 DECEMBER, 1972 PRESTRESSING BY CONTROLLED LOWERING

Continuity in composite steel girder because the steel open trough section and concrete deck bridges presents the would also be prestressed simultaneously. dificulty that the composite section has a The use of prestressed precast deck slabs greater resistance to positive bending as in (c) would have required the provision moment (at mid-span) than to negative of a suitable shear connection between bending (over the intermediate piers). As the slab and the girders after the pre- a result, it is customary to increase sub- stressing was complete. This shear con- stantially, the thickness of the steel girder nection could have been in the rorm of plates in the negative moment re&'lion over bolts combined with epoxy adhesives, the the piers. This practice, however, does extra cost of which would have out- not prevent cracks developing in the weighed the advantages in this case. concrete deck due to girder bending over These two procedures were therefore the piers or from the effects of the discarded in favour or a combinaiion of shrinkage of the concrete against the (d) and (a). restraint of its attachments to the girders. By the use of the moment redistribution In designing the bridge at Camden, technique, major variarions in the thick- alternative proccdures were considered ness of steel plate in the steel trough for improving the negative moment sections have been avoided. This has capacity of the composite girder at the allowed the use of a relatively constant piers. These were: cross-section throughout the len.gth of (a) the provtsion of additional steel the bridge. The width of the top Ranges reinforcement in the deck slab over varies from 16 in at mid-span to 30 in the piers to act compositely with the over the piers. The total cross-section at rest of the composite girder; the piers was further increased by the (b) the prestressing of the region over the use of approximately 40 sq in of rein- piers by means of high tensile steel forcement per girder in the deck slab. tendons embedded in the deck; The controlled lowering also produces (c) the use of prestressed precast deck an initial compression in the concrete slabs instead of a cast-in-place deck; deck slab to counteract the efl'ects of (d) the redistribution of the bending shrinkage and tensile stresses over the moments by controlled lowering at piers. the supports during construction. A brief description of the controlled This procedure reduces negative lowering of the superstructure at the moments at the piers and increases supports is given on page 62. mid-span positive moments. Although this method has been used Of the above alternatives, (b) would successfully in recent years for continuous have required a large amount of prestress steel plate open trough girder structures to prevent the concrete deck cracking in Europe and also, with slight variations,

PAGE 60 MAIN ROADS FABRICATING THE GIRDERS

in Japan, this is probably its first large The plates were then assembled in a later being fillet welded to the bottom scale use in major bridge building jig to form an open trough girder, each flange and web plates. StilTener bsams practice in Australia. girder being first made up in an upside were welded along the bottom flange The contractor for the construction of down position. The plates were tack plates, and the stud shear connectors, the bridge, John Holland (Constructions) welded together to give sufficient strength around which the concrete was later Pty Ltd, subcontracted the fabrication to make the girder self-supporting. The to be cast, were placed using a stud of the 114 steel plate open trough girder girder was then held at each end by a welding gun. segments to the firm of Improved Con- clamp arrangement and set on trunnions Finally, the girders were milled at each structions Pty Ltd whose workshops are which allowed it to be rotated to any end to ensure that the ends were square at Villawood, approximately 23 miles position for welding. and would fit together in the field and north of Camden. The weld of the bottom flange plates the bevels for the field welds were cut. These girder segments were fabricated to the web plates was a full penetration Protective Painting in lengths of 30, 60, and 70 ft and the corner butt weld. A single bevel on the 30-ft segments each weighed IO tons, insidc of the web was the only plate On arrival at the site, the girders were while the 60- and 70-ft segments each preparation. This weld was made up of a sand-blasted to a near-white metal finish weighed approximately 20 tons. The steel root pass done manually, followed by and given an initial protective coat of an used for the top and bottom flanges was two passes of automatic submerged arc inorganic zinc ethyl-silicate primer to a notch-ductile structural steel Grade N.D. welding on the inside. The root run was minimum thickness of three thousandths 1, Class B. and that used for the webs, later back-gouged from the outside and of an inch on the outside surfaces, and diaphragms, and other plates was ordinary filled with a further pass of submerged four thousandths of an inch on the inside mild structural steel. arc weld. The weld of the top flange plates surfaces. The inside surfaces will receive Being “open trough” girders they are to the web plates was a full panetration no furthcr coating, hut the outside made up from five separate steel plates- tee butt weld and a single bevel on the surfaces have been painted with a vinyl two top flange plates, two web plates, outside of the web allowed access for the top coat, to a minimum thickness of and a bottom flange plate. The girders are weld build-up. This weld was made up of three thousandths of an inch. An “Elco- 4 ft 4% in high, 7 ft wide across the four passes of manual electric arc welding meter” thickness gauge was used to bottom, and 9 ft wide at the top between on the outside, with a back gouge of the measure the thickness of these coatings. the webs. The two top flanges are 1 in root pass and two manual weld passes The top painl coat on the bridge at thick and vary in width from 16 to 30 in. on the inside. The completed welding Camden will be blue instead of the eoni- The single bottom flange varies in thick- was checked by both radiographic and monly used grey of earlier steel bridges. ness from + to 1 in. The two web plates ultrasonic procedures. The usc of colour is aesthetically pleasing are of an inch thick and are inclined A diaphragm plate was placed in those and is expected to be a feature of future at 1 in 4 from the vertical. girder segments which were to be sup- bridges. The new Stockton Bridge, north The five separate plates which make up ported on the bearings at the pier. The of Newcastle, has bright red handrails, etc., each girder were initially fabricated diaphragm plate and all stiffeners were while the new expressway bridge being separately by welding to length and made up as a sub-assembly, the dia- buill across the Hawkesbury River at cutting to width, the web plates being cut phragm being placed in position when Mooney Mooney will have a dark green to the required camber. the girder plates were assembled, and finish.

DECEMBER, 1972 PACE 61 Field Welding To allow easier placement of the weld metal (as well as to provide protcction for the welders) a single Vee bevel plate preparation was permitted for the fi.eld welding. Control tests carried OUI: at the commencement of the job indicated that the distortions arising from the use of thc single Vee preparation (instead of the more normally used double vee level preparation) would be within acceptable limits. Manual electric-arc welding using low hydrogen electrodes was used for field welding. The weld Vee was filled from the inside with 4 or 5 passes and the surface of the weld ground flush for appearance and radiography purposes. The root pass of the weld was then gouged out from the ERECTING THE GIRDERS outside using an arc-air gouging procedure and the gouge so formed was filled with a single pass of weld metal and ground A single crane was used to lift each each continuous length at the final level flush. girder into place by means of a lifting but with the centres approximately 26+ Testing of Wdds frame with four “grabs” to hold the inches above the final level for the four- All field welding was checked radio- girder under the top flanges. The girders span continuous lengths and 58f inches graphically and, in the box corners, were erected onto scaffold towers placed above the final level for six-span lengths. checks were made with an ultrasonic at approximately the quarter points of Once in place, the girder segments were probe. each span. set to the required levels and aligned For the radiographic checks. a film correctly-the ends being brought to the inside a plastic sheath was attached to The initial erection of the girders was required &-in__ root face gap, ready for one side of the weld. On the other side a to a cambered profile with the ends of field welding to commence. stand was set up into which a radioactive isotope was to be posilioned. The isotope was stored in a lead-lined container and MNSTFIVC~ION YUJENCE mR CONTROLLED LOWERWW it was necessary to keep the area clear (SIX SPAN CASE SHOWN1 because of the danger of radiation. The operator moved the isotope to the stand by means of a screw thread device and gamma rays from the isotope passed through the metal to impinge on the film. The length of exposure time (usually 2. to THE STEEL GlRDIR gCMENlS *RE ERBTEDTOA -0 PRCFN ON X4FFCCD TOWERS AND FIEU) WELDED THEGlRDERS ARE SUPWRTED ABOVE TIL RERS BT TEHPORW mlBBIffi 5 minutes) depended on the strength of the isotope, the thickness of the plate and the distance from the plate. This non-destructive testing of the welding was carried out for the Depart- ment by the firm, Metlabs Pty Ltd, of Guildford. Weld metal flaws which did not comply with the specification requiremeni.s, were removed, replaced, and then re-checked. Following the approval of the welding, the temporary towers were removed and the girders were then supported from the THE CONTINKUS LENGTH W WRSTWCTURE IS UWERED TD ITS FINM POSITON ON THE PERMANENT BVIRlffiS piers on rail cribbing. THE LOWERING IS CARRIED hlT SIMULTANEOUSLI AND PROPORTIWVATELI AT ALL PIERS The Formwork At this stage the formwork for the deck was set up. The forms above the ~~ - -,-a=-= kJTd trough girders were of plywood pieces supported on light steel beams over cross I-_ L-J I a ~ -~ frames, which were removed and re-used. THE CONCRETE FWTWm AND CRASH 8WPJERS ARE C*sTcRAS+ RAILINGS AND HANDRAILINGS ARE ERECTED THE ASPHAUIC CONCRETE WEARINO SURFICE IS RlCED The forms erected between the girders and the cantilever forms were ‘of steel

PAGE 62 MAIN ROADS and were hung from the transverse beams The jacks took the weight of the girders, extension had to be allowed for in the which were supported rrom the top flanges some of the support cribbing was removed initial setting up of the girders on the of the girders. The reinforcement was then and the girders lowered by means of the piers. positioned and tied, and ready mixed jacks until they rested on the lowered There were two length change effects. concrete with a minimum strength of support cribbing. The jacks were rcset One related to the change in plan length 4,000 Ib:sq in was placed in the deck. and the procedure repeated. between the initial cambered profile and The surface of the 7%inch thick deck As mentioned above, the maximum the final profile. This change was A inch has been finished with a vibrating screed, lowering distancc was 58% inches for the for a four-span case and + inch for a six- and then floated off and broomed. six-span continuous lengths and 26: span case. The other change related to inches for the four-span continuous the stresses brought about by the lowering Prcstrcssing I3.v Controlled Lowrrinf lengths. The lowering procedure pre- which caused the bottom Range to increase When all the deck concrete was ade- stressed both the steel trough girders and in length by 1 inch for a four-span case quately cured and at least 28 days old, the composite concrete deck, inducing a and by lt inch for a six-span case, while the girders and deck in a continuous set tensile stress of about 5,000 Ib/sq in into the concrete deck shortened by + inch for were lowered to the final profile, i.e., to the bottom flange of the girder and a a four-span case and by 11 inch for a the permanent bearings on the inter- compressive stress of about 500 lbkq in six-span case. mediate piers. There are five continuous into the concrete deck. When the superstructure was down to lengths of girders in the bridge-a four- These stresses wcre related solely to the its correct profile, the bearings between span set, three six-span sets, and another bending moments induced by the con- the girders and piers were grouted and four-span set. trolled lowering and not by any thrust packed. With the completion of the The lowering was carried out using from restraint at the ends. In fact, the lowering, the follow-up work of placing jacks placed on cribbing set up between girders were free to extend during the the footway, crash barriers, and railings, the support cribbings for each girder. controlled lowering operation and this was able to commence 0

TENDERS ACCEPTED BY COUNCILS

The following tenders (in excess of rSl0,OOO) for road and bridge works were accepted by the respcctivc Councils during the three months ended 30th September, 1972.

Council Road No. Work or Service ame of Successful Tenderer mount

$ Ashford S.H. 16 . Construction of 12-cell 6 ft x 5 ft N. Del Gatto 14,810.74 reinforced concrete box culvert at 5.6 miles west of Yetman. Ashford M.R. 137 Bituminous surfacing of various sections from: 28 to Emolcum (Australia) Ltd 17.748.99 29.3 milcs north of Inverell; 9 to 10.6 miles north of Ashford; 12.2 to 14 miles north of Ashford. Ashford M.R. 187 Construction of 12-cell 11 ft x 11 ft reinforced concrete N. Dcl Gatto 40,698.45 box ciilvcrt ovcr Smedleys Gully, 43.4 miles north of I nverel 1. Bibbenluke S.H. 19 . Construction of earthworks, Monaro Road 67.401.00 drainage and minor ancillary works, between 18.3 Construction Pty Ltd and 21.3 miles south of Bombala. Blacktown M.R. 537 Extension of reinforced concrete box culvert at Mavis Hill Bros. Construction 12,211.00 Street, Rooty Hill. Pty Ltd Coolah M.R. 206 Construction of six-span reinforced and prestressed A. Cipolla and Co. 60,716.80 concrete bridgc, 210 ft long, over Sandy Creek 14.2 Pty Ltd miles south-west of Dunedoo. Cudgegong Developnicntal Manufacture, supply and delivery of prestressed and Dyson-Holland 12,Y 52.00 Work 3216 reinforced concrete girders for bridge over Wyaldra Prestressed Pty Ltd Creek, 2.5 miles north of Gulgong. Goobang M.R. 233 Cnnstruction of 3-cell 12 ft x 12 ft reinforced concrete A. Cipolla and Co. 16,612.40 box culvert over Back Goobang Creek 9.2 miles Pty Ltd north of Parkes. North Sydney Various Replacement of deteriorated or deformed asphaltic Bituminous Pavements 12,181.50 concrete on various roads. Pty Ltd South Sydney Various Rcplacemcnt of deteriorated or deformed asphaltic Pioneer Asphalts 18,920.00 concrete on various roads. (N.S.W.) Pty Ltd Wollongong Southern Construction of reinforced concrete box culvert over A.R.C. Engineering 12,260.06 Expressway Byarong Creek at the Avenue. Pty Ltd Wollongong S.H. I Prince’s Highway. Constrtiction of a crib block Fred Berridge 19,965.14 retaining wall opposite Nimbin Street, Corrimal. Constructions

DECEMBER, 1972 PAGE 63 TENDERS ACCEPTED BY THE DEPARTMENT OF MAIN ROADS

The following tenders (in excess of $lO,ooO) for road and bridge works wcrc accepted by the Department during the three months ended 30th September, 1972. -.-- -.-- Road No. Work or Service Name of Successful Tenderer Amount

$ North Western City of Sydney. Supply of 593 precast column seg- Peter Verheul Pty L.td 336,633.00 Expressway ments for construction of viaduct in Darling Harbour Goods Yard.

North Western City of Sydney. Supply of high-tensile steel hardware Macalloy (Australia) Pty Ltd 155,233.62 Expressway for post-tensioning precast columns in Darling Harbour Goods Yard.

South Western City of Campbelltown. Construction of twin 3-span Allied Constructions Pty Ltd 2')4,011.35 Expressway prestressed and reinforced concretc bridges, 187 ft long, over Badgelly Road at Campbelltown.

State Highway No. 1 Prince's Highway. City of Wollongong. Manufacture Frankipile Australia Pty Ltd .12,349.95 of reinforced concrcte bridge pilcs for bridge over Fairy Creek.

Statc Highway No. 1 Prince's Highway. Municipality of Bega. Construction Peter Verheul Pty Ltd I, 173,581.OO of 23-span prestressed and reinforced concrete bridge, 2.046 ft long, over the Bega River at Bega.

State Highway No. 2 Hume Highway. Municipality of Camden. Manu- Peter Verheul Pty Ltd 37,767.00 facture, delivery and erection of 9 precast, pre- tensioned, concrete girders for bridge over Macarthur Road at Camden.

State Highway No. 7 Mitchell Highway. Shire of Molong. Supply of 7,300 L. J. Osborne 15,516.00 cu yds of lower course gravel and 3,700 cu yds of upper course material for reconstruction between 5 and 7 miles west of Molong.

State Highway No. 7 Mitchell Highway. Shire of Molong. Supply of up to D. C. Kennett 13.500.00 9,000 cu yds of natural gravel or crushed rock base course material for reconstruction between 7.6 and 8.7 miles west of Molong.

State Highway No. 7 Mitchell Highway. Shire of Wellington. Construction A. Cipolla and Co. Pty Ltd 29,751.30 of a 2-cell 12 ft x 12 ft reinforced concrete box culvert at 16.3 miles west of Wellington.

State Highway No. 9 . City of Maitland. Manu- Basic Industries Pty Ltd 30,510.00 facture and deliverv of orecast. metensioned con- crete units for bridge okr Foui Mile Creek, 6.5 miles east of Maitland.

State Highway No. 9 New England Highway. City of Maitland. Haulage W. D. Smith (Constructions) 45,500.00 of up to 50,000 tons of slag skulls from B.H.P. Pty Ltd stockpile to approaches of bridge over Four Mile Creek, 6.5 miles east of Maitland.

State Highway No. 9 New England Highway. City of Maitland. Supply and Bituminous Pavements Pty Ltd 24,780.00 delivery of 2,000 tons oft in gauge asphaltic con- crete for reconstruction between Maitland and Rutherford.

State Highway No. 10 Pacific Highway. Shire of Lake Macquarie. Supply and Boral Road Services Pty Ltd 17,260.00 delivery of 1,300 tons of 3 in gauge asphaltic con- crete for reconstruction at Catherine Hill Bay turnoff. State Highway No. 14 . Shire of Hay. Stabilisation of foamed Emoleum (Australia) Ltd 26,057.61 bitumen and compaction of surfacc course pavement from 14.4 to 16.4 miles west of Hay.

...... Shire of Hay. Supply of $6 and # in aggregate to Hay Graham Stevenson Pty Ltd 22,401.50 Works Office...... Supply and delivery of up to 1,200 tons of hot mixed, Bituminous Pavements Pty Ltd 19,827.00 cold laid bituminous plant mix to various stockpile sites in the South Grafton Works Ofice area.

PAGE 64 MAIN ROADS