GWR 5400 Class

The Great Western Railway (GWR) 5400 Class was a class of 0-6-0 pannier tank steam locomotive. They were similar in appearance to many other GWR tank engines but smaller than the ubiquitous GWR 5700 Class.

The nominally Collett-designed 5400 Class had 5 ft driving wheels for greater top speed with autocoaches, and were all fitted with the required remote control gear for working the push-pull autotrains. They had a modern cab and a larger bunker. They were frequently seen on inner suburban routes from Paddington.

History
The 5400 class was related to the GWR 2021 Class saddle tank, designed by William Dean and built at Wolverhampton railway works. This was a light, compact design with 4 ft wheels, itself derived from the smaller Armstrong GWR 850 Class dating from 1874.

The prototype was not a new engine, being rebuilt from 2021 Class No. 2062 in 1930. It was given larger wheels, splashers and coal bunker, and the new units from 1931 onwards had the rounded-edge cab as well. This cab style was to be fitted to all subsequent GWR pannier tank designs, including the later derivations of the 5700 Class.

Despite its success, the prototype, No. 5400, had a short life, lasting only two years before being scrapped. It was used as a parts donor for an all-new engine with the same number. 25 locomotives were built and they were numbered 5400–5424.

Withdrawal and mileages
Withdrawal from service with BR started in 1957 and was completed in 1963. The last ones in service were No. 5410, No. 5416, and No. 5420.

le Fleming noted that the mileages of those withdrawn between February 1957 and February 1958 were "from 671,000 to 775,000".

GWR 6400 and 7400 classes
The GWR 6400 Class and 7400 Class that followed were closely related, fundamentally differing only in wheel size – 4 ft – and, in the case of the 74xx, a higher boiler pressure of 180 psi. This produced two general purpose classes with wide route availability. The 6400 was auto-fitted but more suitable for hilly routes than the 5400. The 7400 was not auto-fitted.