Built in 1890 by Cockerill of Liege, Belgium, the loco is a standard 0-4-0 shunting engine but quite different to British locos. It has a vertical boiler married to a "normal" 0-4-0 chassis using Walschaert's valve gear as opposed to the normal British practice of using Stephenson's valve gear.

1625 was kindly donated to the Middleton Railway by the late Mr Hugh Wainwright's Estate in 1997 and was the oldest locomotive in the operating fleet until it was withdrawn from service in December 2000 following the expiry of its 10 year boiler 'ticket'.