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 2 in (1.575 m) 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.