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The AAV program has been in existence since the late 1960s and has seen a number of different contractors supporting the various upgrades to the vehicle. The AAV will, however, be fully replaced by the Advance Amphibious Assault Vehicle (AAAV) within a 15 year period and the AAV RAM/RS program, which maintains the AAV in a cost effective and affordable manner until this replacement, is only a four year program. Therefore, the AAV facts of life would not typically interest the type of contractors necessary to appropriately support the AAV. In order to interest industry in supporting this important combat vehicle for its remaining life, the AAV RAM/RS Team offered industry the opportunity to compete for a contract that would select an offeror who would initially perform the hull modifications and parts buy on the AAV RAM/RS program and also provide long term Technical, Engineering and Management Support (TEAMS) and Foreign Military Sales (FMS) support. This innovative concept resulted in the original manufacturer, United Defense (formerly FMC) returning as an integral member of the AAV government/industry team. Additionally, industry was offered and has accepted location of its manufacturing facilities within the LogBases with potential use of its work force on agreed upon FMS efforts. This arrangement allows stabilization of the government's expert work force through industry business innovations to the government production line, and the availability of a dedicated industrial partner for the service life of the AAV.
The AAV7A1 is the newest Assault Amphibian in a series that started with the Roebling ALLIGATOR. The Alligator was developed over a period of 7 years, starting in 1932. The first "Gators" were a disappointment, in that the water speed was only 2.5 mph. The land speed was 25 mph. Through design changes, and by using larger engines, the water speed of the Alligator was increased to 8.6 mph by 1939. In 1940, Roebling built a new model which was designated the CROCODILE. The Crocodile had a land speed of 25 mph and a water speed of 9.4 mph.
The LVT-1 was a direct copy of the Crocodile, except that it was fabricated from sheet steel instead of aluminum. The LVT-1 was in production from 1941 to 1943. Being heavier, the land speed of the LVT-1 was 18 mph and the water speed was 7 mph. A 6-cylinder, 146 hp Hercules engine was used for power. The LVT-1 was propelled by two endless chains fitted with cleats, both in the water and on land. The first LVT-1's were used as logistic support vehicles only. They were not armored and carried no armament, however, this soon changed. At the Battle of Tarawa, bolted on armor plate was used and the vehicles were equipped with one to four 30 cal. machine guns.
The second generation of LVT's was the LVT-2. This vehicle was developed in 1941 and was in production from 1942 to 1945. The LVT-2 was the basic design for a series of vehicles used during WW II. This family of vehicles included the: LVTA1, LVTA2, LVT4, LVTA4, and LVTA5. A few of the LVTA5s were modified in 1949 and continued in service until the mid 1950s. These vehicles were powered with 7-cylinder radial aircraft engines built by Continental Motors. These engines developed 220hp, their service life was very short. Major overhaul was scheduled for 100 hours, however few ever lasted that long. The transmission was a 5 speed, manual shift SPICER that incorporated a manually operated steer differential. This transmission had been developed for the M-3 light tank. As a result, the transmission was too narrow for the LVT. This problem was overcome by using four final drives. The internal finals were bolted to the transmission / differential gear case and supported by two mounting yokes. The external final drives were bolted to the hull and powered the drive sprockets. This generation of LVTs was used through the Okinawa campaign in 1945. |
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發表於 07-5-27 12:40:45
