Many features of the MBT-70 were ahead of their time. The vehicle used an advanced hydropneumatic
suspension system that allowed for fast cross-country speeds even though it was to weigh 50 short tons (45,000 kg). The suspension could be raised or lowered on command by the driver, down to put the bottom of the tank just over 4 inches (100 mm) from the ground, or up to 28 inches (710 mm) for cross-country running.
The MBT-70 was designed with a low silhouette, unlike the M60, one of the tallest tanks ever built. The MBT-70 ended up very low, just over 6 feet (1.8 m) from the floor to the turret-roof. The driver therefore had to be moved into the big turret, where he was located in the cupola, which rotated so that he was always looking in the direction the tank drove. The tank was therefore capable of driving backwards at full speed.
The US version was to mount the newly developed Continental AVCR air-cooled V-12 diesel of 1,470 horsepower (1,100 kW). German versions originally used a similar Daimler-Benz model, but later moved to an MTU design of 1,500 horsepower (1,100 kW). The MTU unit could be easily swapped out of the tank, along with the drive train, in 15 minutes. Both versions could reach 43 miles per hour (69 km/h) on their engines, at the time an unheard-of speed for such a heavy tank. Armament
Diagram of the XM-150E5 gun/launcher The XM-578E1 APFSDS The 20 mm autocannon deployed MBT-70 prototype test firing an MGM-51
The MBT-70's main armament was a stabilized XM-150 152 mm gun/launcher, a longer-barreled and improved variant of the XM-81 gun/launcher used in the light M551 Sheridan and the M60A2 'Starship'. This gun/launcher could fire conventional 152 mm rounds like High Explosive, anti-personnel, High Explosive Anti-Tank (HEAT) and Armor Piercing Fin-Stabilized Discarding Sabot (APFSDS) rounds, but also the Shillelagh missile, a 152 mm guided missile, which had a combat range of some 3,000 metres (9,800 ft). In the 1960s the effective combat range of the 105mm L7 tank gun was considered to be about 1,800 metres (5,900 ft). The XM578 APFSDS round was made of a newly developed tungsten alloy, which was 97.5 percent tungsten. This new alloy had a density of 18.5 g·cm³, which was a big improvement compared to the older tungsten-carbide APDS and APFSDS rounds. Another new feature of the ammunition was that the tank rounds were "caseless"; i.e., they had combustible cases. The MBT-70 was equipped with a laser rangefinder and an auto-loader, located in the turret rear, two 'cutting edge' devices for this time. The auto-loader was capable of loading both the missiles and the normal tank rounds.
The Germans were planning to use the MBT-70 in combination with the Keiler, a tank built on the MBT-70 chassis equipped with a Rheinmetall 120 mm smoothbore gun, therefore some MBT-70 prototypes were tested with the 120 mm gun. The MBT-70 would destroy enemies at long ranges, while the Keiler would have an effective combat range of up to 2,000 metres (6,600 ft).
The secondary armament of the MBT-70 consisted of a remote-controlled 20 mm autocannon for use against aircraft and light armoured vehicles. The autocannon had a caliber-length of 85 and was stored inside a container behind the driver's rotating cupola. It could be retracted to reduce the overall height. Furthermore a 7.62 mm machine gun was mounted coaxially alongside the main gun for close-defense.
The ammunition load of the MBT-70 prototype seen in the Deutsches Panzermuseum consists of 42 tank rounds, 6 Shillelagh missiles, 660 20 x 139 mm cannon rounds and 2,700 7.62x51mm NATO machine gun rounds. Protection
The MBT-70 was protected by a newly developed type of spaced armor in the frontal area of the hull and the turret. It consisted of an outer layer made of cold-rolled hardened steel and a softer inner steel layer, which also served as spall liner with space between the two. This type of armour offered better protection against armor-piercing and HEAT warheads, which were by then one of the strongest threats against tanks. The armor offered protection against 105 mm APDS at a range of only 800 metres (2,600 ft). The design included bulkheads, fireproof doors, and blow-out sections in the ammunition storage area to minimize crew injury when a hit was received.
The tank's low silhouette, which could be lowered from 2.59 metres (8 ft 6 in) to only 1.99 metres (6 ft 6 in), was also a big advantage. Compared to the M60 tank, the MBT-70 had a lower profile. With the hydropneumatic suspension lowered it was also smaller than the Leopard 1, which gave the MBT-70 a better hull down position.
For protection against neutron radiation a 15 to 20 cm thick layer of polythene was installed around the crew compartment. The MBT-70 was protected against electromagnetic pulses and nuclear, biological and chemical weapons as well. Mobility
The MBT-70 was capable of reaching a top speed of 43 miles per hour (69 km/h), and maintained a higher level of mobility than any tank of its time. It was considerably faster than the M60 and even faster than the Leopard 1 tank. It also could accelerate three times faster than the M60. In cross-country performance the high power engine and hydropneumatic suspension allowed it to travel almost three times as fast as the M60 without causing problems for the crew.