Engine from HMS 'Prince Albert', 1864.
© Science Museum / Science & Society Picture Library
Model (scale 1:12). A horizontal direct-acting engine constructed by Humphreys and Tennant. The engine had two cylinders each 72 inches in diameter by 3 feet stroke, and were remarkable for the shortnes of their connecting rods, which were only 63 inches long, or 3.5 times the crank radius. The engines indicated 2121 hp at 61 revs per minute and drove a propeller 17 feet in diameter, 2.5 feet long, with a 21 feet pitch. The 'Prince Albert' was a coast defence armour- plated turret ship, built at Blackwall, London.