British Rail Class 503
class of British 3-car electric multiple units
British Rail Class 503 trains were 70mph (110km/h) electric multiple units. They were introduced in two batches — in 1938 by the London, Midland and Scottish Railway (LMS) with a further batch (built to a similar design) in 1956 by the then nationalised British Railways (BR).
| British Rail Class 503 | |
|---|---|
 A British Rail Class 503 train on the Liverpool Loop and Link underground system. This train was one of the original batch built by the LMS in 1938. | |
| In service | 1938-1985 |
| Manufacturer | London, Midland and Scottish Railway, British Railways |
| Formation | power car + trailer + driving trailer |
| Operator(s) | LMS and British Railways |
| Specifications | |
| Car length | 58ft 0in |
| Width | 9ft 11in |
| Height | 11ft 10 1/4in |
| Maximum speed | 70mph (110 km/h) |
| Weight | Total - 77 tons |
| Power output | 4 x 135 hp traction motors total 540 hp (403 kW) |
| Electric system(s) | 650V dc third rail |
| Track gauge | standard gauge |
