Harvey is a tank engine with a crane mounted on top of his boiler, which makes him look rather unusual.
With perhaps the most distinctive appearance of any engine, Harvey is painted burgundy with yellow lining and brown, square, wooden buffers. His name is written in yellow on his sides. His number, 27, is written on both sides of his crane arm in yellow.
Harvey is based on Dubs Crane Engine No. 4101, nicknamed "Dubsy", built in Glasgow, Scotland. Dubsy is presently based at the Foxfield Railway in Blythe Bridge, Staffordshire.