The EPV5 type is a vertical 5 cylinder diesel engine. It was housed at the Royal Ordnance Munitions Factory in a windowless bunker, guarded by a Lewis gun post, and close by was a purpose built reservoir to pump water for the site in case of fire.

Installed originally at a pumping station at Ely Wells, Cardiff in 1851 to pump clean drinking water for the citizens of Cardiff. A water pumping station was erected after polluted water from the River Taff had killed one in fifty of the population of Cardiff in an outbreak of cholera in 1850. Taken out of service in c1882 and subsequently moved to Llanishen Reservoir in Cardiff where it worked until 1921rem