Pump trolleys were used for inspecting the track. Built by the Sheffield Car Co., Three Rivers, Michigan, USA, this inspection pump trolley was probably built in the 1920s to their model 45 design of not earlier than 1889. It is the same type as features in older American Westerns and "The Great St Trinians Train Robbery" film. It is propelled along the track by pumping the handle up and down like a see-saw.

It has engineering links to our velocipede car and was used on the Great Eastern's Buntingford branch line. Purchased for six shillings (30p) in 1966, it will be restored for use and demonstrations here at the Buckinghamshire Railway Centre. It arrived at Quainton 25 May 1996.

The Sheffield company traced its origin back to around 1824, and was brought by its own agent, Fairbanks Morse and Co. in the 1890s. It then merged with Colt Industries in 1964. The Three Rivers factory was closed in 1960.