Parachute tower  A parachute tower is a tower used for parachute training, often by members of a military paratroop unit. A mixture of tower heights are used at different stages of training. Trainees typically begin on towers around in height in fall-arrest harnesses before progressing onto parachute descents from towers that can be in excess of . The use of towers allows trainees to practice their landing technique before jumping from an aircraft. Parachute towers are used to train people, particularly military paratroopers, in parachute jump technique. Towers are typically divided into low towers of approximately and high towers of around or higher. The shorter towers are used by trainees jumping in harnesses with a fall-restraint cable to simulate the exit from an aircraft and safe landing technique. Trainees then pass onto the high tower jumps with parachutes. The high tower typically has one or more arms at the top from which the trainee is winched up into the air and released to descend by parachute. The parachutes used are specific variants developed for training and were originally modified commercial systems, though the US military later developed the Type J-I parachute specifically for high tower jumps. The high tower allows trainees to practice the "body landing" (or parachute landing fall) technique, which is essential to avoid injuries such as broken legs or ankles. The high tower can also be used to carry out "shock harness drills", intended to simulate the initial shock of a parachute canopy opening. The trainee is hauled up into the air and dropped to free fall approximately before being brought to a complete stop. After high tower training is passed troops proceed onto aircraft jumps from an altitude of approximately . In the United States Army during the Second World War, five jumps from aircraft were sufficient to complete the course; the British Army required trainees to undertake an additional two jumps from tethered balloons prior to jumping from aircraft. The first parachute tower in the United States was a tower in Ocean County, New Jersey, built by Stanley Switlik and first used by Amelia Earhart on 2 June 1935. The Parachute Jump ride at the 1939 New York World's Fair (later moved to Coney Island) was a parachute tower, though the United States Army parachute training centre at Fort Benning had only towers until 1941. Major William Lee of the United States Army, in charge of the training of the first 48-man platoon of US paratroopers, saw the Parachute Jump ride and constructed a similar tower at Fort Benning. Three further towers were later erected.