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:''This article is about the steam locomotive. For the diesel operated by V/Line, see V/Line N class.'' The N class was a branch line steam locomotive that ran on Victorian Railways from 1925 to 1966. A development of the successful K class 2-8-0, it was the first VR locomotive class designed for possible conversion from to . ==History== In 1923, in response to the recommendations made by the 1921 Royal Commission on the matter of uniform railway gauge, VR announced a policy that all new locomotive designs were to be capable of conversion from broad to standard gauge.〔Pearce et al., p. 12〕 The rationale was that the task of converting VR from broad to standard gauge at a future date would be far easier to achieve if the existing locomotives and rolling stock could be easily modified for standard gauge operation, rather than requiring expensive re-engineering or replacement. The K class 2-8-0 built by VR in 1922-23 was a success, but with a firebox mounted between frames engineered for broad gauge operation only, it was not readily gauge-convertible. Thus when additional branch line locomotives were required, the VR produced a 2-8-2 'Mikado' variant of the K, the first 2-8-2 tender engine in Australia. It retained the same wheels, cylinders, motion, and much of the frame of the K,〔Pearce et al., p. 14〕 but featured a longer boiler with a wider, larger grate, mounted above the frames and supported by a trailing truck. This enabled possible gauge conversion without radical re-engineering of the frames and grate. Despite these design features, no N class locomotive ever ran on standard gauge. By the time the standard gauge Albury to Melbourne mainline opened alongside the existing broad gauge line in 1962, steam locomotives were rapidly being withdrawn from service. Large scale standardisation of Australia's broad gauge rail network did not get underway until 1995, nearly thirty years after the withdrawal of the N class. ===Production=== Twenty N class locomotives were built by VR's Newport Workshops between 1925 and 1928. A second batch of ten locomotives followed in 1930-1931. They went into service with road numbers N 110-139. A third batch of fifty locomotives were later built by North British Locomotive Company in 1949-1950 as part of 'Operation Phoenix', the postwar rebuilding of Victorian Railways. A fourth batch of twenty N class of a modified design were also ordered from Newport Workshops. The class at this time was renumbered, with numbers 400-429 assigned to the pre-war Newport locomotives, 450-499 assigned to the North British locomotives, and 430-449 reserved for the postwar Newport locomotives. However, production of the fourth batch ceased in 1951 after just three had been built, as VR opted to order more of a new design of 2-8-0 branch line locomotive, the J class. VR also decided to sell ten of the North British-built N class locomotives (N's 461, 465, 471, 474, 477, 485, 490, 491, 494, and 495)〔(【引用サイトリンク】 title=N class steam locomotives )〕 to South Australian Railways, which was experiencing a motive power shortage, where they became that system's '750 class'. Many of these locomotives had only run a few days in VR service before being transferred to the SAR. Thus although a total of 83 N class locomotives were built, only 73 were in actual VR service for any substantial period of time. 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「Victorian Railways N class」の詳細全文を読む スポンサード リンク
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