(German vehicle image). From the beginning it was clear that MBT/KPz-70 was a masterpiece, and stood out for its mobility, far superior to any model in service at that time. This did not mean that the vehicle did not have some serious problems. The vehicle was designed to have a maximum weight of 46 tons, but during its development it was surpassed, reaching 54 tons. This excess forced to redesign different components with the consequent delay and cost increase. Finally, the tank remained just over 50 tons, 10% more than the projected weight.(American vehicle image). Here we can see the layout of the hatches and various devices. In the image, to the right of the gun is the driver’s cupola and behind it is the the 20mm gun pop-up assembly. At the left, in the front of the turret, we could see the rangefinder’s aperture, and just behind it, the gunner’s hatch. Finally, behind the gunner is the commander’s hatch, with 6 vision blocks surronding the opening, (at the same height as the 20mm gun assembly).(American vehicle image). The use of the Teledyne Continental Model 2812 dual piston hydropneumatic suspension allowed the MBT/KPz-70 to have a very low profile, which required placing the driver inside the turret. It had a mobile cupola that allowed it to look in the same direction even if the turret was turned and could also turn and look back if necessary. Nevertheless, this system caused dizziness and sense of disorientation to drivers.(American vehicle image). The hydropneumatic suspension was developed by the National Water Lift Co., a division of Pneumo-Dynamics Corporation. This type was installed in the first two prototypes and in the rest a similar suspension manufactured by the German Friesecke & Hopfner GmbH company was used.(American vehicle image). Two different engines were selected for the MBT/KPz-70 tank. Germany chose a MTU MB-873 Ka multifuel engine and the U.S. chose a Continental AVRC-1100 multifuel engine. Both were of “variable geometry”, that could vary the compression ratio by supercharging and air injection. The tank could start, run and stop with the engine completely submerged without preparation.(German vehicle image). The engine was attached to a Renk HSWL-354 hydraulic transmission with 4 forward gears and 4 reverse gears. This tank, thanks to the driver’s mobile cupola within the turret, could go backwards at full speed. The MBT/KPz-70 had an exceptional acceleration and a surprising off-road mobility, calculating both performances 3 times higher than those of the M-60 tank.(German vehicle image). The MBT/KPz-70 had an environmental protection system inside the turret, that created an air overpressure. This device was developed by Draeger-Pillar, Brown Boveri GmbH and Webasto from Germany and allowed the tank to fight in contaminated environments longer than any tank in service. The tank was protected against electromagnetic pulses, against Nuclear, Bacteriological and Chemical contamination and against neutron radiation thanks to a thick layer of polyethylene installed in the crew compartment.(American vehicle image). The passive protection was composed by a new spaced armour consisting of two layers of different thickness separated by an air gap space of 127mm between them. This new armour was applied to the front of the turret and the hull. The outer layer was made of 34mm in thickness hardened steel and the inner layer was of 46mm thick and acted like a spall liner for the crew. This armour was effective against APFSDS and HEAT projectiles mainly.(German vehicle image). The armament must be the 152mm XM-150 gun-launcher, capable of firing HEAT, APFSDS, smoke and HE anti-personnel rounds and Shillelagh anti-tank missiles. The APFSDS round was newly designed based on tungsten and all the projectiles had combustible cases. This tank had an automatic loader that allowed to reduce the crew to only three members. As a secondary weapon, it had a 20mm Rh-202 remote controled gun and a 7.62mm coaxial machine gun.(German vehicle image). The XM-150 gun-launcher was a development of the XM-81 gun installed in the Sheridan M-551 light tank and M-60A2 Starship main battle tank. It was an improved and longer barreled gun than XM-81, but it also suffered from numerous inconveniences, which motivated the frontal rejection of the Germans from the first moment.(German vehicle image). The Shillelagh missile had an IR guidance system, an effective range of 5 km and reached a speed of 4,200 km/h. It had a 6.8 kg HEAT warhead and a minimum gathering range of 1,143 meters. The tactical concept was to use missiles against distant targets thanks to its greater accuracy and normal shells against closer targets, in which the gun would be more effective thanks to its higher rate of fire.(German vehicle image). The MBT/KPz-70 would have been a formidable opponent in the battlefield thanks to its advanced fire control system, its laser rangefinder and its gun stabilization system. These devices gave it great chances of hit the target at the first shot, even firing in movement. According to one of the prototypes conserved in Germany, the ammunition load could be composed of: 6 Shillelagh missiles, 42 152mm shells, 660 20mm rounds and 2,700 7.62mm rounds.(American vehicle image). The MBT/KPz-70 project had been budgeted at around 80 million dollars, but in 1969, during the tests phase, more than 300 million dollars had already been spent, something totally unaffordable. Germany had contributed to the effort with around 130 million dollars.(American vehicle image). Before cancellation, the American design team made an “austere version” of the MBT-70 designated as “XM-803“, which was intended to save the project. The XM-803 had the same hull but with a simplified Teledyne Continental Model 2857 hydropneumatic single-piston suspension system. The turret armor was reshaped and the 20mm gun along with the 152mm gun-launcher’s bore evacuator were removed. An improved Allison HSWL-354 Powershift transmission was installed, which replaced the German components and the automatic loader was redesigned by General Motors.(American vehicle image). Despite modifications, some problems persisted in the XM-803 prototype. For example, the driver was still installed inside the turret and was still suffering from seasick, a worrisome problem in certain occasions. This version ended up costing around 600,000 dollars, three times as much as estimated at the beginning, so the U.S. Congress decreed the end of the joint program definitely.(American vehicle image). Although the MBT/KPz-70 did not materialize, its development can not be described as complete failure. Thanks to this program, enormous advances were made, which have been applied to the next generation of tanks and that represented an enormous enhancement of some of the capabilities of all the current main battle tanks. This project led to the development of two of the most important MBTs of all time, the German Leopard 2 and the American M-1 Abrams.
