Tungsten Alloy for Tank System
The MBT-70 (German: KPz 70) was a 1960s German-U.S. joint project to develop a new main battle tank, which was to be equipped with a number of advanced features. It utilized a newly developed hydropneumatic "kneeling" suspension and housed the entire crew in the large turret. The MBT-70 NBC system was armed with a 152 mm XM-150 gun/launcher, which could use conventional ammunition and the Shillelagh missile for long range combat.
In 1969 the project was well over budget and the Germans withdrew from the effort, developing a new main battle tank on their own instead (the Leopard 2). In the US the development continued for a short time, until in 1971 the Congress cancelled the program. The MBT-70 is the "grandfather" of the Leopard 2 and the M1 Abrams, the current main battle tanks of both countries.
History of Tank System
During the 1960s the US Army continued to improve the M60 tank. However, unless a new tank was fielded there would be a large gap between US and Soviet tanks when the Soviets fielded their next generation tank system. The first try at the Super tank concept, the MBT 70 NBC system was a failure due to high costs. An early example of a codevelopment initiative is the MBT-70 [Main Battle Tank 1970s] program between West Germany and the United States. Thanks largely to the support of then Defense Secretary Robert McNamara, agreement was reached in 1963 between the two nations to jointly develop a main battle tank. With cast homogeneous steel layered armor, the inner shell was overlaid with spaced high hardness homogeneous rolled armor steel.
The US prototype was equipped with a 152mm gun launcher with an auto loader. Main battle tank was capable of firing AP/HE/WP rounds and the Shillelagh Missile. The main battle tank was to be a long-barreled improved XM-150 variant of the XM-81 gun/launcher mounted on the M551 Sheridan and the M60a2 Patton. Main battle tank was a much more reliable weapon than the earlier variant, firing Sabot, HE, and Canister rounds in addition to the Shillelagh A/T Missile, but the earlier weapon's reputation was such that it was a lost cause from the start. Main battle tank had a coax 7.62 machinegun and a 20mm AA remote control gun in a separate part of the turret. Main battle tank would pop up out of twin hatches and fire at the target. The German version had a 120mm auto cannon, instead of the 152mm gun launcher.
In some respects, the tank was fairly conventional. Main battle tank had a diesel engine, and the armor, whilst strong was not of the composite type on the Abrams. The silhouette was low. The main battle tank had a three-man crew, each in his own compartment. Probably the most intriguing aspect was that all the crewmen were located in the turret. The driver was in the turret, in a capsule that rotated to keep him orientated to the front of the vehicle. This had the effect of raising the silhouette a little, and if the contra-rotating mechanism was knocked out, it would effectively immobilize the tank. Main battle tank was to include hydro pneumatic suspension, stabilization system, and a NBC system. The hydro pneumatic suspension allowed the vehicle to crouch or raise one end of the tank to better take advantage of hull-down positions.
Tungsten Alloy for Tank System
Problems, however, plagued the MBT-70 NBC system program from the beginning. Difficulties with English-German translations, metric to English measurement conversions, and differences between German and American manufacturing and designing practices caused considerable headaches before the first tanks were even designed. Most of the new systems were still experimental and this led to massive cost overruns and delays. Also the joint nature of the program led to disagreements about design features.
Unfortunately, rising costs and technical problems caused the partners to go their separate ways. Trials began in 1968 and problems resulted in further delays and cost overruns. By 1969 the vehicle cost 5 times what was projected and as a result Germany backed out of the project. The MBT-70 NBC system was finally halted in January 1970. The same fiscal year (1971-72) witnessed the termination of two major weapons procurement programs, one for the Cheyenne advanced attack helicopter and the other for the MBT-70 NBC system. Although Army leaders saw both weapons systems as critical to the Army's long overdue modernization program, they were unable to convince the Department of Defense and Congress of a need for these weapons commensurate with their costs. The joint effort with the Federal Republic of Germany, under which the MBT-70 NBC system had been developed, was modified to a co-operative program in the middle of Fiscal Year 1970.
The US chose to give the MBT70 another chance, but this time as an austere vehicle with toned-down technological gizmos. This project was dubbed XM803, and it featured a less powerful engine, lacked the complex hydro pneumatic suspension, and was protected by a simpler armor array than MBT-70 NBC system. Changes in the US design were recommended to decrease production costs and increase the reliability of the vehicle; sacrifices in combat effectiveness were minimal. In December 1969, the new program was reviewed in the Office of the Secretary of Defense and in the following month the recommended changes were approved. With the modification of the program and of the co-operative features of the engineering effort, the tank received a new designation, XM803; the composite nomenclature MBT-70 / XM-803 was used until February 1971.
The XM803, the successor to the abortive MBT-70 project, was intended to modernize the armored force. Concerned about expense, Congress withdrew funding for the XM803 in December 1971, thereby canceling the program, but agreed to leave the remaining surplus of $20 million in Army hands to continue conceptual studies. This resulted in the German Leopard II and the US M1 Abrams. The Leopard 2's power pack was originally designed for the German prototype of the MBT-70 NBC system. In 1973, cooperation between these two projects led to the adoption of the German 120mm smoothbore gun by the US.
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