in the middle The 108 was formed as a 2-, 3-, or 4-car unit. Its aluminium body led the type to be classed as a lightweight unit. These units stayed in regular service until 1990, when they began to be withdrawn from traffic. They were replaced on regional services by the new
Sprinter derivative units, or by
Turbo units on services around London. The final units lasted in traffic until October 1993, although many saw further use in departmental service, as
sandite or route-learner units. Good condition on withdrawal and lack of
asbestos have ensured that many of this class are now used on preserved railway lines. == Orders ==