William Chapman

William Chapman (1749–1832) was an English consulting civil and mining engineer who, together with the colliery viewer John Buddle, was responsible for the Steam Elephant locomotive of around 1815 — one of the earliest twin-cylinder steam locomotives, built for the Wallsend Colliery waggonway — and who also patented an early chain-drive system for locomotive traction, one of the first systematic attempts to solve the adhesion problem on smooth railway rails.

Born at Whitby, Yorkshire on 23 October 1749, Chapman trained as a civil engineer and accumulated wide engineering experience across canal, dock, and mining projects in Britain and Ireland. He worked on the Kildare Canal in Ireland, the Stratford-upon-Avon Canal, and various Tyneside dock and waggonway schemes, building the network of professional contacts in the Tyneside coal trade that brought him into collaboration with John Buddle at Wallsend.

Chapman's chain-drive patent of 1812 proposed that a locomotive should propel itself by hauling on a continuous chain attached to fixed points, eliminating the dependence on adhesion between wheel and rail that many engineers of the period doubted was adequate for hauling useful loads. The Steam Elephant, built around 1815 for the Wallsend waggonway, used two cylinders driving a common crankshaft in an arrangement that anticipated later twin-cylinder locomotive practice. Chapman was the elder brother of the engineer Edward Walton Chapman and a fellow of both the Society of Antiquaries and the Royal Society of Edinburgh. He died at Newcastle on 19 May 1832.