MBT-70
Encyclopedia
The MBT-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 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. In the US the development continued for a short time, until in 1971 the Congress cancelled the programme. The MBT-70 is the "grandfather" of the Leopard 2
and the M1 Abrams
, the current main battle tanks of both countries.
were the newest main battle tanks in their respective country's service. While designed to counter the T-54/55 tanks, both tanks were placed at a disadvantage by the new smoothbore
gun fielded in the T-62
. It became clear that the next generation of Soviet
tanks would have increased firepower and protection. An upgrade project for the Leopard was planned, but it appeared this model would not be enough of an advance to be worthwhile.
To solve the problems in the tank forces, Germany and the United States had a memorandum of understanding
to develop a common new tank for both armies. However, this may have been one of the worst things to happen to the project, as both teams started "pulling" the design in their own directions. Arguments arose over almost every part of the design: the gun, the engine, even whether or not the design would use metric
or SAE measurements. This last dispute was eventually "settled" by using both systems, thereby increasing costs considerably.
system that allowed for fast cross-country speeds even though it was to weigh 50 short tons (45,359.2 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 (10.2 cm) from the ground, or up to 28 inches (71.1 cm) for cross-country running.
The MBT-70 was designed with a low silhouette, contrary to the M60, one of the tallest MBTs 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 1470 hp. German versions originally used a similar Daimler-Benz
model, but later moved to an MTU
design of 1500 hp. 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 (19.2 m/s) on their engines, at the time an unheard-of speed for such a heavy tank.
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 HE
, anti-personnel, HEAT
and APFSDS, but also the Shillelagh missile, a 152 mm guided missile, which had a combat range of some 3000 metres (9,842.5 ft). In the 1960s the effective combat range of the L7 tank gun
was considered to be ca. 1800 metres (5,905.5 ft).
The XM578 APFSDS 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. 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 2000 metres (6,561.7 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-defence.
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
and 2700 7.62 x 51 mm rounds.
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 armour-piercing and HEAT
warheads, which were by then one of the strongest threats against tanks. The armour offered protection against 105 mm APDS at a range of only 800 metres (2,624.7 ft).
The design included bulkhead
s, 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 (8.5 ft) to only 1.99 metres (6.5 ft), 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 EMP
s and NBC as well.
The tank proved to be better than the M60: it was considerably faster, both in all-out speed and, more importantly, with about three times the acceleration. In cross-country performance the high power engine and excellent suspension allowed it to travel almost three times as fast as the M60 without causing problems for the crew. All of this led to a reduction in the time the tank was exposed to fire, in testing it was 1/3 less likely to be seen while maneuvering than the M60, and it could run a 10 km (6.2 mi) obstacle course in 30 % less time.
proved to be just as troublesome.
There were also several problems with the ammunition. The caseless design makes the conventional tank rounds too vulnerable to water. Wet rounds expanded so they won't fit into the barrel anymore or left hard residues after being fired. The auto-loader was capable of handling the Shillelagh missile without problems, but the combustible cases of the tank rounds could be deformed by it. As is often a problem with caseless ammo, the ammunition also had a tendency to "cook-off", or fire prematurely, due to heat build-up in the barrel from previously fired rounds. The attempted solution, to only carry a single round with the balance in missiles, also proved unacceptable. Deployment of the 20 mm anti-aircraft cannon also proved difficult and the weapon itself was overly complicated and nearly impossible to use effectively.
Another problem of the MBT-70 was the increasing weight. While at the beginning of the project, a weight of some 46.3 tonnes (45.6 LT) was projected, it increased to 54 tonnes (53.1 LT) during development, which forced the designers to redesign some elements, so that finally a weight of 50.3 tonnes (49.5 LT) was reached, still higher than required. This meant that the MBT-70 would require its own armoured recovery vehicles and bridge-launching systems.
Commentators on the MBT-70 typically assert that though it was innovative in many respects, the project was ruined by the use of too many untried and unproven technologies. A senator from Arkansas, Senator James W. Fulbright
, mentioned that to drive a MBT-70, a master's degree
in a technical institute would be required.
's part of this, not less than $130 million (475.8 million DM), was more than the original planned costs.
Germany backed out of the project, and started the development of the Keiler on its own. Later this programme would lead to the Leopard 2 The Leopard 2
, like the Keiler, uses a 120 mm smoothbore gun.
At this point Congress also began objecting to the rapidly increasing price and soon canceled it in 1970. The Army then introducing a lower-cost system based on the same design, known as the XM803. This succeeded only in producing an expensive system with capabilities similar to the M60 it was supposed to replace.
Congress, angered by the delays and cost overruns, cancelled the project in November 1971, and redistributed the funds to the new XM815. This project was later renamed XM1, the project that led to the very successful M1 Abrams
tank. The M1 had a conventional, but welded steel turret, suspension, and gun, and was innovative in incorporating advanced armor materials and the use of a gas turbine engine.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
-U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
joint project to develop a new main battle tank
Main battle tank
A main battle tank , also known as a battle tank or universal tank, is a tank that fills the heavy direct fire role of many modern armies. They were originally conceived to replace the light, medium, heavy and super-heavy tanks. Development was spurred onwards in the Cold War with the development...
, 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 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. In the US the development continued for a short time, until in 1971 the Congress cancelled the programme. The MBT-70 is the "grandfather" of the Leopard 2
Leopard 2
The Leopard 2 is a main battle tank developed by Krauss-Maffei in the early 1970s for the West German Army. The tank first entered service in 1979 and succeeded the earlier Leopard 1 as the main battle tank of the German Army. Various versions have served in the armed forces of Germany and twelve...
and the M1 Abrams
M1 Abrams
The M1 Abrams is a third-generation main battle tank produced in the United States. It is named after General Creighton Abrams, former Army Chief of Staff and Commander of US military forces in Vietnam from 1968 to 1972. The M1 is a well armed, heavily armored, and highly mobile tank designed for...
, the current main battle tanks of both countries.
History
In the early 1960s the German Leopard 1 and the US M60M60 Patton
The 105 mm Gun Full Tracked Combat Tank, M60, also known unofficially as the M60 Patton, is a first-generation main battle tank introduced in December 1960. It was widely used by the U.S. and its Cold War allies, especially those in NATO, and remains in service throughout the world today...
were the newest main battle tanks in their respective country's service. While designed to counter the T-54/55 tanks, both tanks were placed at a disadvantage by the new smoothbore
Smoothbore
A smoothbore weapon is one which has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.-History of firearms and rifling:...
gun fielded in the T-62
T-62
The T-62 is a Soviet main battle tank, a further development of the T-55. Its 115 mm gun was the first smoothbore tank gun in use.The T-62 was produced between 1961 and 1975. It became a standard tank in the Soviet arsenal, partly replacing the T-55, although that tank continued to be...
. It became clear that the next generation of Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
tanks would have increased firepower and protection. An upgrade project for the Leopard was planned, but it appeared this model would not be enough of an advance to be worthwhile.
To solve the problems in the tank forces, Germany and the United States had a memorandum of understanding
Memorandum of understanding
A memorandum of understanding is a document describing a bilateral or multilateral agreement between parties. It expresses a convergence of will between the parties, indicating an intended common line of action. It is often used in cases where parties either do not imply a legal commitment or in...
to develop a common new tank for both armies. However, this may have been one of the worst things to happen to the project, as both teams started "pulling" the design in their own directions. Arguments arose over almost every part of the design: the gun, the engine, even whether or not the design would use metric
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
or SAE measurements. This last dispute was eventually "settled" by using both systems, thereby increasing costs considerably.
Design
Many features of the MBT-70 were ahead of their time. The vehicle used an advanced hydropneumatic suspensionSuspension (vehicle)
Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose — contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants...
system that allowed for fast cross-country speeds even though it was to weigh 50 short tons (45,359.2 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 (10.2 cm) from the ground, or up to 28 inches (71.1 cm) for cross-country running.
The MBT-70 was designed with a low silhouette, contrary to the M60, one of the tallest MBTs 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
Cupola
In architecture, a cupola is a small, most-often dome-like, structure on top of a building. Often used to provide a lookout or to admit light and air, it usually crowns a larger roof or dome....
, 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 1470 hp. German versions originally used a similar Daimler-Benz
Daimler-Benz
Daimler-Benz AG was a German manufacturer of automobiles, motor vehicles, and internal combustion engines; founded in 1926. An Agreement of Mutual Interest - which was valid until year 2000 - was signed on 1 May 1924 between Karl Benz's Benz & Cie., and Daimler Motoren Gesellschaft, which had...
model, but later moved to an MTU
MTU Friedrichshafen
MTU Friedrichshafen GmbH is a manufacturer of commercial internal combustion engines founded by Wilhelm Maybach and his son Karl Maybach in 1909...
design of 1500 hp. 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 (19.2 m/s) on their engines, at the time an unheard-of speed for such a heavy tank.
Armament
M551 Sheridan
The M551 Sheridan was a light tank developed by the United States and named after Civil War General Philip Sheridan. It was designed to be landed by parachute and to swim across rivers. It was armed with the technically advanced but troublesome M81/M81E1 152mm gun/launcher which fired conventional...
and the M60A2 'Starship'.
This gun/launcher could fire conventional 152 mm rounds like HE
He
He is a third-person, singular personal pronoun in Modern English, as well as being a personal pronoun in Middle English.-Animals:...
, anti-personnel, HEAT
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
and APFSDS, but also the Shillelagh missile, a 152 mm guided missile, which had a combat range of some 3000 metres (9,842.5 ft). In the 1960s the effective combat range of the L7 tank gun
Royal Ordnance L7
The Royal Ordnance L7 is the basic model of Britain's most successful tank gun. The L7 was a 105 mm L/52 rifled design intended for use in armoured fighting vehicles...
was considered to be ca. 1800 metres (5,905.5 ft).
The XM578 APFSDS 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. 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
Rheinmetall
Rheinmetall AG is a German automotive and defence company with factories in Düsseldorf, Kassel and Unterlüß. The company has a long tradition of making guns and artillery pieces...
120 mm smoothbore
Smoothbore
A smoothbore weapon is one which has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.-History of firearms and rifling:...
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 2000 metres (6,561.7 ft).
The secondary armament of the MBT-70 consisted of a remote-controlled 20 mm autocannon
Autocannon
An autocannon or automatic cannon is a rapid-fire projectile weapon firing a shell as opposed to the bullet fired by a machine gun. Autocannons often have a larger caliber than a machine gun . Usually, autocannons are smaller than a field gun or other artillery, and are mechanically loaded for a...
for use against aircraft and light armoured vehicles. The autocannon had a caliber-length
Caliber (artillery)
In artillery, caliber or calibredifference in British English and American English spelling is the internal diameter of a gun barrel, or by extension a relative measure of the 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
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
was mounted coaxially alongside the main gun for close-defence.
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
20 mm caliber
The 20 mm caliber is a specific size of cannon or autocannon ammunition, commonly the smallest caliber which is unambiguously a cannon and not a heavy machine gun....
and 2700 7.62 x 51 mm rounds.
Protection
The MBT-70 was protected by a newly developed type of spaced armourSpaced armour
Armour with two or more plates spaced a distance apart is called spaced armour. When sloped it reduces the penetrating power of bullets and solid shot as after penetrating each plate they tend to tumble, deflect, deform, or disintegrate; when not sloped it increases the protection offered by the...
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 armour-piercing and HEAT
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
warheads, which were by then one of the strongest threats against tanks. The armour offered protection against 105 mm APDS at a range of only 800 metres (2,624.7 ft).
The design included bulkhead
Bulkhead (partition)
A bulkhead is an upright wall within the hull of a ship or within the fuselage of an airplane. Other kinds of partition elements within a ship are decks and deckheads.-Etymology:...
s, 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 (8.5 ft) to only 1.99 metres (6.5 ft), was also a big advantage. Compared to the M60
M60 Patton
The 105 mm Gun Full Tracked Combat Tank, M60, also known unofficially as the M60 Patton, is a first-generation main battle tank introduced in December 1960. It was widely used by the U.S. and its Cold War allies, especially those in NATO, and remains in service throughout the world today...
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
Neutron radiation
Neutron radiation is a kind of ionizing radiation which consists of free neutrons. A result of nuclear fission or nuclear fusion, it consists of the release of free neutrons from atoms, and these free neutrons react with nuclei of other atoms to form new isotopes, which, in turn, may produce...
a 15 to 20 cm thick layer of polythene was installed around the crew compartment. The MBT-70 was protected against EMP
EMP
EMP or Emp may refer to:Science and technology*Electromagnetic propulsion*Electromagnetic pulse, a burst of electromagnetic radiation*Electron microprobe microanalyzer, a tool for chemical composition determination...
s and NBC as well.
Mobility
The MBT-70 was capable of reaching a top speed of 43 miles per hour (19.2 m/s), and maintained a higher level of mobility than any tank of its time. It was considerable 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.Testing
A prototype series started in 1965, with one mild steel hull and six "complete" hulls of both the US and German versions, for a total of 14 hulls. The lower hull and drivetrain were tested in 1966, and full trials began in 1968.The tank proved to be better than the M60: it was considerably faster, both in all-out speed and, more importantly, with about three times the acceleration. In cross-country performance the high power engine and excellent suspension allowed it to travel almost three times as fast as the M60 without causing problems for the crew. All of this led to a reduction in the time the tank was exposed to fire, in testing it was 1/3 less likely to be seen while maneuvering than the M60, and it could run a 10 km (6.2 mi) obstacle course in 30 % less time.
Problems
An unanticipated problem was that the drivers complained of disorientation when the turret was rotated, contrary to the predictions of the designers who felt the location of the cupola near the center of rotation would eliminate this effect. The German 120 mm proved excellent, but the XM-150 was a serious problem. The similar but smaller XM-81 mounted on the M551 SheridanM551 Sheridan
The M551 Sheridan was a light tank developed by the United States and named after Civil War General Philip Sheridan. It was designed to be landed by parachute and to swim across rivers. It was armed with the technically advanced but troublesome M81/M81E1 152mm gun/launcher which fired conventional...
proved to be just as troublesome.
There were also several problems with the ammunition. The caseless design makes the conventional tank rounds too vulnerable to water. Wet rounds expanded so they won't fit into the barrel anymore or left hard residues after being fired. The auto-loader was capable of handling the Shillelagh missile without problems, but the combustible cases of the tank rounds could be deformed by it. As is often a problem with caseless ammo, the ammunition also had a tendency to "cook-off", or fire prematurely, due to heat build-up in the barrel from previously fired rounds. The attempted solution, to only carry a single round with the balance in missiles, also proved unacceptable. Deployment of the 20 mm anti-aircraft cannon also proved difficult and the weapon itself was overly complicated and nearly impossible to use effectively.
Another problem of the MBT-70 was the increasing weight. While at the beginning of the project, a weight of some 46.3 tonnes (45.6 LT) was projected, it increased to 54 tonnes (53.1 LT) during development, which forced the designers to redesign some elements, so that finally a weight of 50.3 tonnes (49.5 LT) was reached, still higher than required. This meant that the MBT-70 would require its own armoured recovery vehicles and bridge-launching systems.
Commentators on the MBT-70 typically assert that though it was innovative in many respects, the project was ruined by the use of too many untried and unproven technologies. A senator from Arkansas, Senator James W. Fulbright
J. William Fulbright
James William Fulbright was a United States Senator representing Arkansas from 1945 to 1975.Fulbright was a Southern Democrat and a staunch multilateralist who supported the creation of the United Nations and the longest serving chairman in the history of the Senate Foreign Relations Committee...
, mentioned that to drive a MBT-70, a master's degree
Master's degree
A master's is an academic degree granted to individuals who have undergone study demonstrating a mastery or high-order overview of a specific field of study or area of professional practice...
in a technical institute would be required.
Cancellation
By 1969 the MBT-70 cost five times what was projected, at $1 million a unit ($ in present-day terms). Originally the planned costs of the MBT-70 project were as low as $80 million (or 292.8 million DM), but in 1969 the project had already costed $303 million (nearly 1.1 billion DM). Alone West GermanyWest Germany
West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....
's part of this, not less than $130 million (475.8 million DM), was more than the original planned costs.
Germany backed out of the project, and started the development of the Keiler on its own. Later this programme would lead to the Leopard 2 The Leopard 2
Leopard 2
The Leopard 2 is a main battle tank developed by Krauss-Maffei in the early 1970s for the West German Army. The tank first entered service in 1979 and succeeded the earlier Leopard 1 as the main battle tank of the German Army. Various versions have served in the armed forces of Germany and twelve...
, like the Keiler, uses a 120 mm smoothbore gun.
At this point Congress also began objecting to the rapidly increasing price and soon canceled it in 1970. The Army then introducing a lower-cost system based on the same design, known as the XM803. This succeeded only in producing an expensive system with capabilities similar to the M60 it was supposed to replace.
Congress, angered by the delays and cost overruns, cancelled the project in November 1971, and redistributed the funds to the new XM815. This project was later renamed XM1, the project that led to the very successful M1 Abrams
M1 Abrams
The M1 Abrams is a third-generation main battle tank produced in the United States. It is named after General Creighton Abrams, former Army Chief of Staff and Commander of US military forces in Vietnam from 1968 to 1972. The M1 is a well armed, heavily armored, and highly mobile tank designed for...
tank. The M1 had a conventional, but welded steel turret, suspension, and gun, and was innovative in incorporating advanced armor materials and the use of a gas turbine engine.
Surviving vehicles
Altogether 14 prototypes and test-beds have been built, two of them were made of mild steel. Some of them have survived in museums and can still be visited today.US-American prototypes
- One prototype is located in the US Army Ordnance Museum in Aberdeen, Maryland
- A mild steel prototype in bad condition can be seen in the Military Museum of the Southern New England in Danbury, CT
German prototypes
- One prototype is located in the Deutsches Panzermuseum Munster
- Another is located in the Wehrtechnische Studiensammlung Koblenz