The Alternating Current Multiple Unit (A.C.M.U.) Society was formed in 2025 as the formal merger between two railway preservation groups, the Clacton Express Preservation Group and the Class 315 Preservation Society.

The society is the proud owner of Class 315 No. 315856. We also provide restorative support and upkeep for two vehicles of Class 309, No. 309624, and the sole surviving vehicle of Class 317, No. 317345, now owned by the East Anglian Railway Museum in Essex, England, plus the other vehicle of 309624, now based at the Rushden, Higham and Wellingborough Railway.