|
No.6880 ''Betton Grange'' is a steam locomotive which is under construction as a "new-build" project, based on the Llangollen Railway in Denbighshire, Wales. Described as "building the 81st Grange", the project started in 1998, and the locomotive was expected to be operational by 2013. All of the original GWR 6800 Class ''Grange'' locomotives were withdrawn for scrap by the end of 1965; this project is a creation, from an assemblage of original GWR and newly manufactured components, of a member of this class. ==History== (詳細はG.J. Churchward envisaged a range of locomotive classes which would be suitable for the majority of duties, and yet which would share a small number of standard components. Amongst the designs suggested in 1901 was a 4-6-0 with diameter coupled wheels, and the Standard No. 1 boiler. Although planned in 1901, none were built until 1936, by which time C.B. Collett was in charge at Swindon. He took the Churchward proposal, and modified the design of the cab and controls to the then current style. The 4300 Class of 2-6-0 tender locomotives had been introduced in 1911, and by 1932 there were 342 in service. With train loads and hence weights rising, these smaller, older and less powerful locomotives were scheduled to be replaced by new 4-6-0 locomotives by the 1930s. The ''Granges'' were effectively a smaller-wheeled version of the GWR Hall Class.〔 The GWR also built a lighter version of the ''Granges'', the GWR 7800 Class, known as the ''Manor'' Class, which had smaller boilers.〔 Between 1936 and 1939, 100 of the 4300 Class were taken out of service, and stripped of their parts at Swindon Works. The initial plan was to rebuilt 80 as the 6800 ''Grange'' class, whilst the remaining 20 were of the 7800 ''Manor'' class. It had eventually been intended to replace all of the 4300 Class in this way in three batches, with the next ''Grange'' due to be built No. 6880 ''Betton Grange'', to be named after the manor house in the Shropshire hamlet of Betton Strange. But the onset of Second World War stopped the programme.〔〔 The wheels, valve motion and tenders of the ''Grange'' were taken from the withdrawn engines, reconditioned and then used in the construction of the 100 new locomotives;〔 with the components from one old locomotive spread amongst more than one of the new engines. The cylinders of both the ''Granges'' and ''Manors'' were of the same size as those used on the 4300 Class, but the old cylinders could not be re-used because the cylinders and valves shared a common casting, and the new design called for the separation between cylinder and valve centre lines to be increased by . This was done in order to make the cylinders level with the axles, but still allow the use of the old valve motion parts. The 6800 class had driving wheels of diameter, four inches smaller than those of the ''Hall'' class. However, as their cylinders were of the same size and the two classes shared the Swindon No. 1 boiler, the ''Grange'' had a tractive effort 1,600 lb greater than the ''Hall''.〔 Hence, with their power and mixed traffic characteristics, the ''Grange'' locomotives could handle most duties on the network.〔 The British Railways power classification of the Grange class was 5MT, its GWR power class was D and its route availability colour code was red. In service they were reliable performers.〔 The last of the ''Grange'' class was withdrawn and scrapped in 1965, and none were preserved.〔 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「GWR 6800 Class 6880 Betton Grange」の詳細全文を読む スポンサード リンク
|