1938-1940: Class 502 and 503 trains
While many railways persisted with slam door trains well into the second part of the 20th century, the London, Midland and Scottish Railway chose a different approach for their new trains for Merseyside, becoming an early adopter of air-operated sliding doors, opened and closed by the guard.
The trains were introduced on the LMS's newly-electrified routes to West Kirby and New Brighton in 1938. In 1939/40 a second, different design of train was introduced on the lines out of Liverpool Exchange to Southport and Ormskirk, to replace the original L&Y trains.
(picture credit: Paul Gorton)
The design was undoubtedly inspired by the new trains then being introduced on the London Underground, but the LMS units were the first main line trains to use the idea.
So successful was the design, that when British Railways needed new trains to replace the life-expired Mersey Railway units in 1956, they opted for a second batch of the LMS Wirral units, despite the fact the design was by then 18 years old.
(picture credit: Paul Gorton)
The Southport and Ormskirk trains were later designated class 502 by British Railways and survived in service until 1980. The Wirral units became class 503 and survived until 1985. Virtually all commuter trains in the UK follow the basic layout pioneered by the 502 and 503 trains, with open saloons and doors at 1/3 and 2/3 positions on the carriage.
