M103 (battle tank)

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M103A2
M103A2 tank at the Fort Lewis Military Museum

M103A2 tank at the Fort Lewis Military Museum

General properties
crew 5 (commander, driver, radio operator, gunner, loader)
length 11.32 m
width 3.71 m
height 11 inches 8 feet = 3.56 m
Dimensions 59 t
Unit price $ 300,000 (1954)
Armor and armament
Armor 245/127 mm
Main armament 120 mm M58 cannon
Secondary armament 2 × 7.62 mm MG M1919A4E1
1 × 12.7 mm MG M2
agility
drive Diesel engine
750 PS (552 kW)
suspension Torsion bar
Top speed 34 km / h
Power / weight 11.5 hp / t
Range 480 km

The M103 was a heavy tank of the times the Cold War from American production and to the introduction of the M1 Abrams of the heaviest American tanks. He served with the United States Marine Corps and the United States Army .

history

Planning

Prototype of the T29 main battle tank

During the Cold War, the M103 was developed to withstand a direct confrontation with heavy Soviet tanks. Towards the end of the Second World War , several heavy battle tanks were under development for the United States Army ( T28 or T95, T29 , T30 , T32 and T34). None of these vehicles reached series production. In 1948 another prototype called the T43 was completed. Another four pre-production models up to the T43E1 followed. The latter then went into series production. Between December 1952 and June 1954, Chrysler and the Detroit Arsenal Tank Plant produced 300 units. It was not until 1953 that it was finally named M103 .

The main task of the M103 in the US Army was to be the precise combat against enemy tanks in support of its own tanks and infantry units over long distances. The second task was to provide fire support for its own medium battle tanks when they were deployed from a position from which the battlefield could be overlooked. The United States Marine Corps viewed the vehicle as a weapon system of the second wave, which should follow the light forces of the first wave during amphibious landings and then fend off a possible enemy counter-attack with heavy tanks.

The Marine Corps ultimately emerged as the driving force behind the project after Chief of Staff J. Lawton Collins , apparently under the influence of industry officials, criticized the role of the tank on the future battlefield.

Usage history

In 1957/58 the first vehicles were handed over to the armed forces, the last M103 were in service with the United States Marine Corps until 1973. The production had to be changed several times due to changed requirements of the army and vehicles that had already been produced were brought up to date with upgrade kits. The list price when ordered in December 1950 was approximately $ 500,000.

After the first batch of 300 vehicles, 114 individual defects had to be rectified over the next few years. The fire control system proved to be inadequate to fulfill its main task, direct fire at long distances. The tower swivel mechanism and leveling system did not work precisely enough in the first series vehicles and they quickly lost their calibration. These problems affected the entire tower construction and required a fundamental renovation. The tower slewing mechanism and straightening system were converted from hydraulic to electric motors. The gunner , who had previously been sitting to the right of the commander in the rear of the turret, was relocated to the front third of the turret in front of the right loader. There he received new target optics, his old target optics were coupled with the commandant's vision device, who could now override the gunner if necessary and use the main weapon. A stereoscopic rangefinder was also installed under the tower roof . The ammunition store for two-part ammunition shells was set up at the old gunnery area. In addition, the tank now called "M103A1", but only in the version of the United States Marine Corps , received a tower cage, in which the floor rotated with the tower and on which the loaders could stand and work. The vehicle was also more suitable for more dynamic combat situations at shorter distances than the US Army version, where the priority was still on fire support from a great distance.

Equipped with the AV-1790-C (604 kW) petrol engine , a variant of an engine from the M47 battle tank , which was ten tons lighter , the M103 was quite immobile at 34 km / h and 80 miles (130 km) range per tank. This was less of a problem with the original assignment, but the more flexible battlefield that the Marine Corps planners expected required more engine power and greater range. Therefore, it was on the AVDS-1790-2A diesel engine of the main battle tank M60 upgraded. Since this was larger, the engine compartment in the tub had to be redesigned and the engine air filters moved from the engine compartment into external boxes on the chain covers next to the engine. The new range of the M103A2 was 300 miles (483 km) and the top speed reached 37 km / h.

No M103 tank was ever used in combat. However, units of the US Army stationed in southern Germany were equipped with the M103. A unit of the 33rd Armor Regiment in West Germany was equipped with 72 M103A1s that the US Army had borrowed from the US Marine Corps for the purpose in 1959.

Production was ultimately discontinued in favor of the M60 program. A specially designed model had to be developed for the M103 with the M51 armored recovery vehicle.

Versions

M103A2 in the Bovington Tank Museum

M103A1

With the installation of an improved fire control system (Steroscopic T52), the installation of a T33 fire control computer and the attachment of a tower cage, a total of 219 vehicles were converted to the M103A1 model in 1959. One of the two coaxial machine guns was removed. The tower's electrical system was reinforced.

M103A2

In 1964, 153 vehicles were further improved by the installation of an AVDS-1970-2AD diesel engine from the M60 tank (which increased the road driving range to 480 km), a new XM2A distance measuring device and 152 other improvements and modifications. The A2 was only used by the US Marine Corps.

technical description

The cast hull of the vehicle corresponds to the extended hull of the M48A2 main battle tank. The M103 had a support roller drive with torsion bar suspension, which was taken over from the M47 and extended by one roller. The connector chain was guided over seven rollers and six support rollers on each side. The drive wheels were at the stern, the idlers at the front of the vehicle. The higher weight of the M103 accelerated the wear and tear of the drive. The tank was equipped with IR driving lights and an IR / white light target light coaxial with the cannon. This had an elevation range of −8 to +15 degrees and was not stabilized. A smoke evacuator was installed near the mouth ; there was no muzzle brake . The commander's cupola is in the center of the tower in the rear area. The ammunition (like the heavy Soviet tanks with the 122 mm cannon) had to be loaded separately ( cartridge and projectile ). The reasons why the ammunition for the cannon was only carried separately is not known (the narrow space in the tower would be possible). There were 34 rounds of 120 mm ammunition , 5250 rounds of 7.62 mm ammunition and 1000 rounds of 12.7 mm ammunition on board.

Technical specifications
M103 M103A1 M103A2
crew 5 (including 2 loaders)
Main armament 120 mm M58 cannon
Secondary armament 2 × 7.62 mm MG Browning M1919 4E1 coaxial, 1 × 12.7 mm MG Browning M2 on the turret
Length over all 11.32 m
Length of tub 6.98 m
engine air-cooled 12-cylinder gasoline engine Continental AV1790 air-cooled 12-cylinder diesel engine Continental AVDS-1790-2
power 810 hp (596 kW) at 2800 rpm 750 PS (552 kW)
Speed ​​limit road 34 km / h
Driving range 129 km 480 km
Climbing ability 0.91 m
Trench crossing ability 2.29 m
Climbing ability 60%
Wading ability 1.22 m
Ground pressure 0.90 kg / cm 2
Armor mm inch
Tub bow 127 5
Tub side 50 2
Tub roof 25th 1
Cannon mantlet 245 9.7
Tower front wall 127 5
Tower side 70 2.75
Tower roof 38 1.5

Cannon ammunition

Marine infantryman 1959 with propellant charge and (actually separate) M456 projectile.

The following types of ammunition were available:

  • Armor-piercing shells with a ballistic hood; M358 (Armor Piercing Ballistic Capped-Tracer / APC-T)
  • HE shells ; M456 (High Explosive / HE)
  • Armor-piercing shaped charge grenades with tracer and wing stabilization; M469, (High Explosive Anti Tank (Fin Stabilized) -Tracer / HEAT)
  • HE shells with tracer (High Explosive - Tracer / HET)
  • Practice bullets with tracer (Practice - Tracer / PracT)
  • Phosphor Grenades (Phosphorus / PH)
  • Phosphor grenades with tracer (Phosphorus - Tracer / PHT)

Further developments

After the M103 had proven to be a failure, attempts were made, despite the very successful successor M60, to continue developing a heavy battle tank. The following prototypes were built:

  • Main battle tank T54 (in three different versions)
  • Main battle tank T57 (on T43 chassis with 105 mm cannon)
  • Main battle tank T58 (on T43 chassis with 155 mm cannon)
  • Main battle tank T69 (on T43 chassis with 105 mm cannon)
  • Main battle tank T77 (no information available - probably nuclear armament)
  • Main battle tank T110 (no information available - probably nuclear armament)

None of these vehicles got beyond the experimental stage.

Existing copies

M51 armored recovery vehicle

M51 armored recovery vehicle

The existing armored recovery vehicles were not powerful enough for this weight class . An armored recovery vehicle had to be built that met the requirements of the M103. The M51 (prototype designation T6 and T6E1) had a crew of four, a crane with 30 tons of capacity and a recovery winch with 60 tons of pulling power. They were also built at Chrysler and later retired along with the M103. There are contradicting information about the quantities produced.

Individual evidence

  1. MichaelGreen: Tanks . ZenithImprint, 2008, ISBN 978-1-61673-270-7 , AmericanTanks, p. 126 ( excerpt [accessed on July 15, 2015]).
  2. a b c Kenneth W. Estes: "M103 Heavy Tank 1950-74", 2013, Osprey Publishing, ISBN 978-1-84908-981-4 , page 18
  3. ^ United States Congress. House. Committee on Armed Services: Hearings of Special Subcommittee on Development and Procurement of New Combat and Tactical Vehicles by the Department of the Army of the Committee on Armed Services, House of Representatives, Eighty-sixth Congress, Second Session , US Government Printing Office, 1960 , Page 7700
  4. Kenneth W. Estes: "M103 Heavy Tank 1950-74", 2013, Osprey Publishing, ISBN 978-1-84908-981-4 , page 12
  5. Kenneth W. Estes: "M103 Heavy Tank 1950-74", 2013, Osprey Publishing, ISBN 978-1-84908-981-4 , pages 24, 25
  6. Kenneth W. Estes: "M103 Heavy Tank 1950-74", 2013, Osprey Publishing, ISBN 978-1-84908-981-4 , pages 34 and 37
  7. Kenneth W. Estes: "M103 Heavy Tank 1950-74", 2013, Osprey Publishing, ISBN 978-1-84908-981-4 , page 22

literature

  • Kenneth Estes, Richard Chasemore: M103 Heavy Tank 1950-74 . Oxford 2013, ISBN 978-1-84908-981-4 .
  • RP Hunnicutt: Firepower . A History of the American Heavy Tank. New York 1988, ISBN 0-89141-304-9 .

Web links

Commons : M103  - collection of pictures, videos and audio files