GWR 4100 Class - Atbara Class

Atbara Class

No. 3373 Atbara was built in April 1900, the first of a class of forty locomotives. Instead of the curved outside frames of the Badmintons, this class had straight-topped frames, which became the standard pattern for all subsequent outside-framed 4-4-0s. These straight frames were less prone to fracturing, because of the greater depth of plate between the coupled wheels. The Atbaras retained the Stroudley crank layout, cylinders, valves and valve gear of the Badmintons, but differed in the boiler, which was a parallel domeless Standard No. 2 type. No. 3405 Mauritius was reboilered in September 1902 with a tapered boiler, a prototype for the Standard No. 4 type. It was the first GWR 4-4-0 to be fitted with a tapered (or coned) boiler. Following this, another nine Atbaras, nos. 3400 to 3404 and 3406 to 3409, were rebuilt with No. 4 boilers between February 1907 and February 1909. The ten were added to the City Class. No. 3382 Mafeking was heavily damaged in an accident on 24 June 1911. Adjudged unrepairable, it was withdrawn in September 1911, so was not included in the 1912 renumbering. The remaining Atbaras were withdrawn between April 1927 and May 1931.