AMES Type 80 design intended for all of the northern bases became the Mark II. As early as 1950, the RAF had considered several solutions to the original Phase II GCI requirement, including the Royal Navy's new Type 984 radar, the Army's Orange Yeoman, and an adaptation of the Type 80. By mid-1953, the Air Ministry made the firm decision to use the Type 80-derived Type 81 rather than the other designs. Because the Type 81 spread its signal over a much greater vertical angle, the amount of energy in any one angle was lower. This meant the design would have less range
61 cm Type 90 torpedo 61 cm Type 90 torpedo The 61 cm Type 90 torpedo was a surface-fired torpedo used by the Imperial Japanese Navy during World War II. It was used in the s and in most cruisers, including the , , , and heavy cruisers after refits during the 1930s. It was superseded by the Type 93 oxygen-powered torpedo, commonly called the "Long Lance", as oxygen generating equipment was installed aboard the cruisers. The torpedo was based on a newly developed British Whitehead torpedo. This weapon used a new double-action two-cylinder engine rather than the four-cylinder radial engine used by World War