Numbered 1901–2020, they were designed by George Armstrong (responsible to William Dean at Swindon) and built at the Wolverhampton railway works, England, of the Great Western Railway between 1881 and 1895.

Forty-four locomotives survived into British Railways (BR) ownership in 1948.

[1] Only three GWR saddle tank locomotives survived into nationalisation.

2048 which was rebuilt as a pannier tank locomotive shortly after nationalisation and scrapped in 1952.

This article relating to steam locomotives operated in the United Kingdom is a stub.