Ericsson, John (1803–1889)

Swedish-born US engineer who took out a patent to produce screw-propeller-powered paddle-wheel ships 1836. He built a number of such ships, including the Monitor, which was successfully deployed during the American Civil War.

Ericsson was born in Värmland and worked from the age of 13 doing technical drawing for the Göta Canal works. In 1826, he moved to London to seek sponsorship for a new type of heat engine he had invented, which used the expansion of superheated air as the driving force. This was unsuccessful and not until towards the end of his life did Ericsson construct small, efficient engines of this type.

In 1829 he built the Novelty, a steam locomotive which competed unsuccessfully against George Stephenson's Rocket. Ericsson turned to building ships fitted with steam engines and screw propellers, and moved to the USA 1839. In 1849, he built the Princeton, the first metal-hulled, screw-propelled warship and the first to have its engines below the waterline for added protection. The Monitor was the first warship to have revolving gun turrets.

From 1877, Ericsson also explored the possiblity of using solar energy and gravitation and tidal forces as sources of power.