Nissen hut
A Nissen hut is a prefabricated steel structure, made from a half-cylindrical skin of corrugated steel. Originally designed during World War I by engineer and inventor Major Peter Norman Nissen, it was used extensively during World War II.
Description
A Nissen hut is made from a sheet of metal bent into half a cylinder and planted in the ground with its axis horizontal. The cross-section is not precisely semi-circular, as the bottom of the hut curves in slightly. The exterior is formed from curved corrugated steel sheets 10 feet 6 inches by 2 feet 2 inches (3.2 × 0.7 m), laid with a two-corrugation lap at the side and a 6 inch (15 cm) overlap at the ends. Three sheets cover the arc of the hut (about 54 sheets in all are required). These are attached to five 3 × 2 inch (7.5 x 5 cm) wooden purlins and 3 × 2 inch wooden spiking plates at the ends of the floor joists.
The purlins are attached to eight T-shaped ribs (1¾ × 1¾ × ⅛ inch; 4.5 × 4.5 × 0.5 cm) set at 6 feet 0.5 inch (1.8 m) centres. Each rib consists of three sections bolted together using splice plates, and each end is bolted to the floor at the bearers. With each rib are two straining wires, one on each side, and a straining ratchet (or in some cases a simple fencing wire strainer). The wires are strained during construction. The straining wires do not appear in the original Nissen patent.
