Power type Steam Builder Wolverhampton, GWR Build date 1897 (1897) – 1905 | Designer George Armstrong Serial number Works Nos: 625–764 | |
 | ||
Order number Lots: D3, F3, G3, H3, J3, K3, L3, M3 | ||
The GWR 2021 Class was a class of 140 0-6-0 saddle tank steam locomotives. They were built at the Wolverhampton railway works of the Great Western Railway between 1897 and 1905. 1897 was the very year of George Armstrong's retirement, so it is uncertain if the design should be attributed to him or to his superior at Swindon, William Dean.
In fact the 2021s were simple enlargements of the Armstrong-designed 850 class of 1874. The changes were fundamentally confined to a longer wheelbase to permit fitting of a larger firebox.
The class was built in eight batches:
Rebuilding with Belpaire fireboxes commenced in the early years of the Churchward era. Unsuccessful attempts to form a saddle tank around the firebox directly led to the switch to pannier tanks. The rebuilding of the whole class took place over many years. In their final form, with or without fully enclosed cabs, 110 of them survived into British Railways ownership, the last of them being retired in 1956. They were superseded by the short-lived GWR 1600 Class, nominally a Hawksworth design, but in reality a straightforward update of the then 75-year-old design, with new boiler, bigger cab and bunker.