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.

Both groups were founded with the sole purpose of acquiring, maintaining and eventually restoring their Class 309 and Class 315 Electric Multiple Unit (EMU) trains respectively. With similar aims, they found themselves collaborating with each other often in terms of resources and financial management, until it was decided to combine forces into one wider, umbrella preservation society.

The society are the proud owners of Class 315 No. 315856, originally preserved by the Class 315 Preservation Society in 2022 and based at the Llanelli & Mynydd Mawr Railway in Carmarthenshire, Wales, and is regularly visited by our team. We also provide restorative support and upkeep for two vehicles of Class 309 No. 309624 and one vehicle of Class 317 No. 317345, owned by the East Anglian Railway Museum in Essex, England.

Visit our Meet the Fleet page for more information about our vehicles!