Great Western Railway Power and Weight Classification
From 1920, the cab side of Great Western Railway (GWR) steam locomotives bore a letter on a coloured disc, which enabled staff to quickly assess the capabilities of locomotives without the need to check tables of data. The letter showed the power classification, and the coloured disc showed the weight restriction. This system continued after the GWR became the Western Region of British Railways.
A preserved GWR 2884 Class steam locomotive, showing the power classification as a black letter "E" on a blue weight classification disc, painted above the numberplate. Between the disc and numberplate may be seen a white letter "X", which affects how the power class is interpreted
A preserved GWR 4500 Class steam locomotive, showing power classification "C" on a yellow route restriction disc, on the upper cab side-sheet
Two Western Region Diesel-hydraulic locomotives; D7072 (left) is a class 35 showing a red route restriction disc; D6343 (right) is a class 22 and has a yellow disc. Both discs are on the cabsides, below the numbers.
An ex-GWR 6800 (Grange) class steam locomotive, showing a white "X" below the red route restriction disc, indicating that the normal loads for its power class (D) could be exceeded
The British Railways Standard Class 5MT 4-6-0 is one of the 12 BR standard classes of steam locomotive built by British Railways in the 1950s. It was essentially a development of the LMS Stanier Class 5 4-6-0. A total of 172 were built between 1951 and 1957.
A Standard Class 5 at Salisbury in 1963
73140 with Caprotti valve gear and a big tender at Chester General in 1964.
Named Class 5MT, No. 73113 Lyonesse at Battledown flyover. The nameplate is positioned above the centre driving wheel.
73156 and 73082 doubleheading a train at the Great Central Railway in January 2023.
