Class 108 Derby 2,3 & 4-car DMUs

Introduced: 1958
Coupling code: Blue Square
Underframe: 57ft 6in
Engines: Leyland 150hp
Transmission: Mechanical

This was an updated version of the 79xxx series "Derby Lightweights" with an revised cab and blue square control system. 333 vehicles were built over several years for the Eastern (32 sets, 81 vehicles) and London Midland (126 sets, 252 vehicles) Regions — they would later also be allocated to the Scottish and Western Regions.

A two-car set visited Strasbourg for an exhibition of aluminium rolling stock in 1960. The DTC vehicle was displayed as a shell, without any interior fittings or panelling whatsoever, so that the construction could be observed. The power car (52045) was a completed vehicle.

Their alloy construction contributed to a long life, with few withdrawals before 1990. There were plans for a further life extension refurbishment until an accident showed the brittle nature of aging alloy, this resulted in rapid withdrawals — the last vehicles surviving until 1993.

Many entered preservation and also sandite use.