The Constitution was made to guard the people against the dangers of good intentions." --American Statesman Daniel Webster (1782-1852)

Wednesday, March 22, 2023

The Failed MBT 70 Project

 I touched on this a bit when I was doing my "Red Storm Rising" posts a few years ago and I had discussed the "M1 Tank", The failed MBT 70 project was touched on that posting, the United States and West Germany had different ideas on Armor development and Tank usage. THe end results are that both nations built the 2 best MBT's in the world.   I shamelessly snagged this from "SOFREP".


(Image source: Wikimedia Commons)
(Image source: Wikimedia Commons)

World War II came and went, and defeated Germany had been divided into two, with the eastern half falling under the influence of the communist Soviet Union and the western region working alongside the United States.

When tensions grew, and the Cold War era took hold in the late 1940s, western allies perceived the communist region’s rising power as an imminent threat. More potent main battle tanks were developed in case eastern forces decided to attack using their own war machines. This eventually became a race between the two sides to build the most innovative, powerful tanks.

When Russia introduced its T54/55 series, American and West German forces unveiled the MBT (main battle tank) M60 “Patton” and Leopard 1 as the former tank’s capable rival. Soon, however, US intelligence discovered the development of the Soviet Union’s advanced T-62 MBT equipped with powerful arms modifications, and they decided it was time to sprint ahead of the competition.

Subsequently, then-Defense Secretary Robert McNamara proposed an unprecedented “super tank” and initiated the joint battle tank program between the US and West German forces. During this period, the North Atlantic Treaty Organization (NATO) member states lacked cohesion on common military equipment, which McNamara saw as needing improvement.

MBT70 Prototype
MBT-70 prototype undergoing a speed test at Aberdeen Proving Ground. (Image source: Wikimedia Commons)

By 1963, Germany and the US signed a memorandum of understanding that guaranteed both nations equal input in the tank’s design and features. This turned out to be the first big misstep in the program as engineers from both sides later couldn’t agree even on the smallest details, such as which system of measurement use.

“As testing continued, they realized they had another big problem. Because the driver would be located inside a turret that would be rotating in battle, the tank’s designers had come up with the solution of mounting the driver inside his own contra-rotating cupola within the turret. Regardless of the direction the turret was facing, the cupola would automatically face forward. The drivers, however, accustomed to being located in a stationary position at the front of a tank’s hull, were becoming disoriented and suffering from motion sickness.” via Defense Media Network, 2016.

Dubbed MBT-70 by the Americans and KPz-70 by the Germans, the designed super tank comprised promising, ahead-of-its-time features, which caused its eventual cancellation.

Couldn’t Agree on the Design

The main design of the super tank includes a steel-layered tungsten alloy armor and an inner protective shell capable of buffering Soviet ammunition.

But negotiations on the overall design of the tank were riddled with disagreements. Both superpowers had different requirements and standards, not to mention the language barrier. It was almost impossible for the US and German forces to meet halfway.

Nonetheless, prototypes for each side’s versions were produced, with the American MBT-70 powered by a Continental 12-cylinder air-cooled diesel engine that could generate up to 1,470 horsepower and the German KPz-70 powered by a Daimler-Benz MB-873 diesel engine that was later replaced by an MTU diesel engine capable of producing 1,500 hp. Both tanks could speed up to 43 miles per hour within a 400-mile range, making the MBT-70 prototype the world’s fastest MBT at the time.

Designers aimed to hydro-pneumatically lower the height of the MBT-70 compared to its predecessors, seeking to develop a tank with an extremely low profile on the battlefield. As a result, the prototype of the US-German tank was  29.9 feet (9.1 meters) in length, 11.6 ft (3.53 m) in width, and 8.6 ft (2.62 m) in height. The low-profile objective, however, significantly sacrificed the space in the interior, leaving no room for its driver in the hull. Instead of adjusting the compact lower structure of the tank, designers opted to place the driver along with the rest of the crew—in the turret.


While, at this time, this concept may sound ingenious, putting the driver in a revolving turret was just not viable. Why? For obvious reasons, this causes extreme disorientation, and you don’t want to be throwing up when it’s “go time” on the battlefield. Despite adding a “special cupola,” which designers would ensure the driver faces forward regardless of the turret’s direction in an attempt to emulate the driver being the hull, this concept was eventually discarded.

Another radical concept that caused significant technical issues was the tank’s weapons system. Both MBT-70 versions were fitted with a 20mm anti-aircraft cannon and a 7.62mm general coaxial purpose machine gun, The trouble began when they looked at a main weapon. While the German 120mm smoothbore gun looked promising, the American 152mm XM-150E5 main gun mounted on an M551 Sheridan had serious problems. For one thing, the rounds swell when soaked, essentially making them unusable. Moreover, the incorporation of the 152mm Shillelagh guided missile system also gave the engineers headaches. It was an exciting concept—if successful, the MBT-70 would be among the first tanks to be armed with guided missiles. The main problem was that the recoil from firing the Shillelagh completely threw off the missile optics, basically rendering it useless as a precision-guided weapon.

fires MGM-51 missile
MBT-70 prototype test firing an MGM-51 missile (Image source: Wikimedia Commons)

With Problem after problem, the development of the super tank spiraled out of control over the years. Despite efforts to alter and modify the machine, the increasingly high cost and expanding tonnage of the MBT-70 finally prompted everyone involved to abandon the project entirely.

By 1970, the promising yet ambitious super tank collaboration between the US and West German forces had been canceled. The introduction of the USSR’s T-62 and T-64 into service a few years prior also prompted the western allies to have a dependable tank in mass production ASAP, and the MBT-70 apparently was not going to be that tank.

It didn’t go all to waste, though. Yes, the super tank may have never seen the light of day on the battlefield, but this jointly constructed armored vehicle had significantly contributed to future MBT capabilities, notably the development of “XM1,” which would eventually become the famed M1 Abrams family of tanks we have today. Meanwhile, West Germany moved on by developing what later became the Leopard 2.

Both countries produced 14 prototypes of the failed tank throughout the program, with some still being displayed in museums. They serve as a reminder of a once-promising concept that never saw the battlefield. Still, through all of the frustrations, the project managed to help pave the way for future main battle tanks.




  1. I have added a coat of paint to that prototype. Work detail when it was at Knox.

    1. Hey Angus,

      Nothing like "make work" details....ahhh the memories.....beats painting rocks I suppose

  2. The problem with the 152mm wasn't that the Shillelagh would knock out the electronics, but the conventional ammo. The Sheridan and M60A2 both had the same issue.

    Worse, the conventional ammo was very hard on the trunnions.

    MBT-70 would likely have been better than the Sheridan in that regard thanks to heavier construction. The M60A2 didn't suffer from breakage with conventional ammo.


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