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The Hawthorn Bridge is a wrought iron truss bridge across the Yarra River, east of Melbourne, Victoria, Australia. The bridge connects Bridge Road and Burwood Road. It is a substantial riveted, wrought-iron, lattice-truss bridge with bluestone abutments and piers, designed by Francis Bell and is the oldest extant bridge over the Yarra River and is one of the oldest metal bridges in Australia. This crossing was one of the earliest Yarra River crossing points and a major communication route in early Melbourne. The present bridge was constructed in the early wave of major new infrastructure funded by the gold rushes. ==History== Tenders were called on 21 April 1857 by the Board of Land and Works, for erecting the piers for a new bridge, and in the following month, the tender of J. McKenzie was accepted at ₤10,000. A slight alteration had been made to the proposed site to obtain better foundations, while the estimated cost with cuttings being made from both Burwood Road and Church Street, was ₤40,000. The specified date set for completion of the bluestone piers and abutments was December 1857, but they were not finished until February 1858, and the actual cost was ₤10,065. The wrought-iron truss components were ordered from Britain. However, the ship ''Herald of the Morning'', while engaged in carrying this large bridge to Melbourne as deck cargo in 1859, caught fire in Hobsons Bay before it could be unloaded, and was scuttled to extinguish the fire. That original consignment of British wrought-iron bridge materials weighed some 350 tons, and together with its erection cranes had cost ₤10,500, so the sinking of ''Herald of the Morning'' represented a disaster for Melbourne's metropolitan bridge scene. The contractors for the bridge were allowed an extension of time to import similar bridge-works from Britain. Another set had to be ordered, made and delivered, delaying completion of the bridge until November 1861.〔Victoria, Hansard, 1859-60, p. 1063, Legislative Assembly, 3 May 1860 (Smith and Service); also Hansard (Legislative Assembly) 1861, p. 368 (Smith) and p. 1083 (Brooke)〕 A newspaper account gives some further details'':〔''The Argus'' Tuesday 10 April 1860 p 5〕 A Melbourne salvage-contracting firm, Ingles and Gresham, then raised the bridge from the bottom of Hobson's Bay, and brought it into Sandridge (Port Melbourne). While the salvage firm was negotiating with the Victorian Government to pay some ₤6,000 for the salvaged materials. Ingles made the serious mistake of offering Victoria's Inspector General of Public Works, Thomas Higginbotham, a two and half per cent commission on the agreed price. A parliamentary row ensued, the negotiations were voided, and the salvage firm was erased from the Government's list of approved contractors. The pioneer Melbourne foundry of Langlands and Co. then purchased the salvaged bridge materials for ₤2,000, and spent several hundred pounds in repairing or modifying bridge sections. However, there seems to have been no obvious market for the 350 tons of bridge materials, and the Langlands Foundry ended up selling 200 tons of it to the combined rural shires of Metcalfe and McIvor, who had received a substantial Government grant for the construction of the Mia Mia Bridge at Redesdale. The price was ₤1,000, and Langlands disposed of the remainder at ‘scrap iron’ rates. That 200 tons of wrought-iron bridge materials had originally been priced at around ₤6,000, so the goldfields shires were pleased with their purchase. The designer of the bridge has not been confirmed, but as this was one of the largest Public Works Department undertakings at the time, it is plausible the Inspector General of Roads and Bridges in the Public Works Department of the Board of Land and Works, Thomas Higginbotham, himself an accomplished engineer, may have had a hand in it. The design and construction work probably benefited from the knowledge and skills obtained by the Yarra Bridges of the Melbourne & Suburban Railway for their bridges at Cremorne and Hawthorn in 1860-1.〔Harrington, L, 1962, ''Victorian Railways to '62'', p.45〕 In 1885, Hawthorn Bridge was the destination of Melbourne's first tram service.〔(Yarra Trams, ''100 Years of Electric Trams'' )〕 The bridge was widened in 1890 by extending the piers and abutments and adding additional trusses. Because the bridge joins two municipalities and services a tramway, there have always been problems with management, on-going maintenance and finance. In 1928, when funds to repair or replace the bridge were not available, the Richmond City Engineer declared it unsafe and closed it.〔(Engineering Heritage Victoria -A SITE VISIT TO HAWTHORN BRIDGE (1861) )〕 The State Government was forced to act and, after much debate, the bridge was repaired, strengthened and widened by the Railways Construction Branch, using in-situ electric arc welding; the timber deck was also replaced with reinforced concrete.〔 〕 Today, the deck of the bridge retains its 1931 appearance; however, the trusses, piers and abutments underneath appear as they were in 1861. The bridge is listed on the Victorian Heritage Register.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hawthorn Bridge」の詳細全文を読む スポンサード リンク
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