The AM10, later Class 310 fleet were built for use on the 1960s extension of the Lm electrification into London and were principally used on Euston-Birmingham stopping services. The 50 sets were a derivative of the Mk2 coaching stock design and were built by BR at Derby. These sets were novel in a number of ways when introduced, incorporating disc brakes, which on the trailer vehicles operated against axle mounted disc plates. Fluorescent lighting was fitted and the general design was one of a modern state of the art train.
The sets remained working on the Euston route until displaced by more modern Class 321s, the 310s then found work on the London Tilbury Southend route allocated to East Ham. A handful of sets were retained for a period for West Midlands services allocated to Bletchley. By the late 1990s all sets operational were concentrated on the LTS until taken out of regular traffic towards the end of 2001.