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This is a prefabricated steel structure made from a half-cylindrical skin of corrugated steel, was used extensively during World War II. Between April 16 and April 18, 1916, Major Peter Norman Nissen of the 29th Company Royal Engineers began to experiment with hut designs. Nissen, a mining engineer and inventor, constructed three prototype semi-cylindrical huts. The semi-cylindrical shape was derived from the drill-shed roof at Queen's University, Kingston, Ontario. Nissen’s design was subject to intensive review by his fellow officers, Lieutenant Colonels Shelly, Sewell and McDonald, and General Clive Gerard Liddell, which helped Nissen develop the design. After the third prototype was completed, the design was formalized and the Nissen hut was put into production in August 1916. At least 100,000 were produced in World War I