The new locomotives were named after castles, also in the west, beginning with Caerphilly Castle. The last 12 Star class locomotives, which were built in 1922–23, had been given names of abbeys in the western area served by the GWR. They were 4073–4082, the number series continuing unbroken from the Star class. Thereafter the remaining eight locomotives came out at regular intervals until April 1924. Collett was sufficiently confident of the design to place an order with Swindon Works (Lot 224) for ten locomotives in 1923, although there was a four-month delay between the appearance of the first example in August 1923 and the second in December, to allow for the correction of any teething problems. Unlike the Star class, there was no prototype. The result was an increase in tractive effort to 31,625 lb, and a locomotive that looked attractive and well proportioned while remaining within the 20-ton axle limit. The extended frame allowed for a side window cab and an increased grate area. The increased amount of steam that this produced allowing an increase in the cylinder diameter from 15 in × 26 in (381 mm × 660 mm) to 16 in × 26 in (406 mm × 660 mm). Collett's solution was to take the basic layout of the Star with an extended frame, and add a newly designed No.8 boiler which was both larger and lighter. However, this combination would have taken the axle load over the 20-ton limit then set by the civil engineers, and in the end, nothing came of the idea.Ĭharles Collett succeeded Churchward as Chief Mechanical Engineer of the GWR in 1922 and immediately set about meeting the need for a new locomotive design that would both supplement the Stars and replace them on the heaviest expresses. ![]() To meet this need, Chief Mechanical Engineer George Churchward had in mind an enlarged Star class design with a standard No.7 boiler, as fitted to his GWR 4700 Class express freight 2-8-0. The Star class was designed to take the top express trains on the GWR, with 61 in service by 1914, but after World War I there was a need for an improved design. The origins of this highly successful design date back to the Star Class of 1907 which introduced the basic 4-cylinder 4-6-0 layout with long-travel valves and Belpaire firebox that was to become characteristic of Great Western Railway (GWR) express passenger locomotives. ![]() They could reach speeds of up to 100 mph (160 km/h). ![]() They were designed by the railway's Chief Mechanical Engineer, Charles Collett, for working the company's express passenger trains. The 4073 or Castle Class are 4-6-0 steam locomotives of the Great Western Railway, built between 19.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |