GWR are the initials of and number of different organisations and concepts.
The GWR 1400 Class is a class of steam locomotive designed by the Great Western Railway for branch line passenger work. It was originally classified as the 4800 Class when introduced in 1932, and renumbered in 1946.
Although credited to Collett, the design dated back to 1868 with the introduction of the George Armstrong 517 class.
Like the 48xx/14xx, the 517 Class was a lightweight loco for branchline work; it was built at Wolverhampton Works between 1868 and 1885.
In this period evolutionary changes included:
Later gradual changes included: Belpaire fireboxes, boilers rated at 165 psi (1.14 MPa) as opposed to 150 psi (1.0 MPa), full cabs, extended bunkers and the progressive conversion of short wheelbase locos to 15 ft 0 in (4.57 m) or 15 ft 6 in (4.72 m). From 1924 onwards, several were converted to run with an autocoach, and in this configuration were the direct ancestors of the 48xx class.
The Great Western Railway (GWR) 9400 Class is a class of 0-6-0 pannier tank steam locomotive, used for shunting and banking duties.
The first ten 9400s were the last steam engines built by the GWR. After nationalisation in 1948, another 200 were built by private contractors for British Railways (BR). Most had very short working lives as the duties for which they were designed disappeared through changes in working practices or were taken over by diesel locomotives. Two locomotives survived into preservation, one as part of the National Collection.
The 9400 class was the final development in a long lineage of tank locomotives that can be directly traced to the 645 Class of 1872. Over the decades details altered, the most significant being the adoption of Belpaire fireboxes necessitating pannier tanks.
The 9400 resembled a pannier tank version of the 2251 class, and indeed shared the same boiler and cylinders as the 2251, but was in fact a taper-boilered development of the 8750 subgroup of the 5700 class. The advantage was a useful increase in boiler power, but there was a significant weight penalty that restricted route availability. The 10 GWR-built locomotives had superheaters but the remainder did not.