In the middle of the Cold War, there was some debate regarding the main tank weapon of the future, largely focused on conventional kinetic energy rounds (cannon shell) versus missiles. In 1966, in an effort to utilize both capabilities, General Dynamics Land Systems designed a new low profile turret, equipped with a 152mm Gun/Missile Launch system that could fire conventional HEAT (High-Explosive Anti-Tank) and HE (High-Explosive) rounds, or launch ATGMs (Anti-Tank Guided-Missiles).
The new turret was mated to a Medium Tank M60 Patton hull, creating the M60A2, unofficially nicknamed the “Starship”. Though the vehicle was one the most technologically complex of its era, this also contributed to its failure, largely due to difficulties with maintenance, training, and complicated operation.
The M60A2 was designed as a stop-gap vehicle until the joint US-German MBT-70 project was ready for service. This project was intended to provide both the United States and German militaries with one Main Battle Tank. It would use the same Gun/Launcher weapon as the A2 and later in the M551 Sheridan.
The United States ordered the M60A2 in 1971, however, production did not start until 1973, and continued through 1975, at the Chrysler Tank Plant in Warren, Michigan. Initial plans called to replace the turret of every M60 with the new A2 turret, but only 526 vehicles were produced (according to official US Army documentation).
Aside from the turret and weaponry changes, the tank was nearly identical to the regular M60. It featured the same 4.29 in (109 mm) glacis armor, torsion bar suspension, and the 750hp Continental AVDS-1790-2 V12, air-cooled twin-turbo diesel engine which would propel the vehicle to approximately 30 mph (48 km/h).
The M60A2 featured a unique Gun/Launcher mounted in a new, low profile “space age” turret. It consisted of a large disk with a narrow channel in the center. Each crew member in the turret had their own hatch, a rare feature in tanks. As a result, each crew member was effectively isolated from one another with the gunner and loader separated by Shillelagh missiles in their storage position. The commander was isolated in the rear compartment under a large rotating machine gun equipped cupola, which somewhat negated the low profile silhouette of the turret.
There was a mounting point to the left of the gun for a Xenon White-Light or Infrared Spotlight for night time operations. A large basket for storage was added to the rear of the turret and also included banks of smoke-grenade launchers, one bank of four on each side of the turret.
The main feature of the A2 turret, is its main armament, the M162 Rifled 152 mm Gun/Launcher, a weapon similar to the M81E1 found on the M551 Sheridan Light Tank. As mentioned previously, it was capable of firing both HEAT (High-Explosive Anti-Tank) and HE (High-Explosive) rounds or launch the MGM-51 Shillelagh ATGMs (Anti-Tank Guided-Missiles). Load-out for the main armament was 33 conventional rounds and 13 missiles.
The conventional rounds had a range of 1.5km (1640 yds). The HE was a more than capable anti-infantry weapon, while the HEAT ideal for close range anti-armor engagements. For a longer range anti-armor capability, the ATGM was to be utilized.
The Shillelagh ATGM guided system. After acquiring a target a small charge would launch the missile out of the barrel. Once clear, four rear stabilizing fins would deploy followed by ignition of the engine. The missile was guided to the target via IF (Infrared) beam. As long as the gunner kept the target in his scope, the missile would strike accurately. This system, however, contributed to one of the tank’s major issues. The M162 Gun/Launcher experienced frequent faulty breeches. Often, not closing correctly, allowing the exhaust of the launching Shillelagh to vent hot noxious gasses into the crew compartment.
The Gun/Launcher was fully stabilized. This meant that while moving over rough terrain the gun would stay relatively level and the gunner able to keep a target in his sight. This did not apply to the use of the ATGM however, which could not be fired on the move.
An A2 being restocked with the MGM-51 Shillelagh
In early testing, the system was plagued with misfires and premature detonations of the conventional case ammunition, caused by unburnt propellant in the bore and breech. This was often catastrophic as it set off the projectile in the barrel as it was fired. To combat this, early versions of the gun were equipped with a traditional fume extractor on the barrel. Later versions would use the Closed Bore Scavenger system, a compressed air system that pushed the fumes and gasses out of the muzzle when the breech is opened.
Secondary armament consisted of an M85 .50 Cal. machine gun in the commander’s rotating cupola, and a coaxial M73 7.62mm machine gun. Neither weapon was especially liked by the crews and later replaced. For the commander’s cupola, the traditional .50 Cal. (12.7mm) M2HB “Ma Deuce” was installed, and the coaxial replaced by the M240, a license-built copy of the Belgian FN Mag. Loadout for the MGs was 5, 560 rounds of 7.62 mm and 1, 080 rounds of .50 Cal. (12.7mm).
One of the A2’s more hi-tech features was its laser range finder and the M60A2 was the first tank to be equipped with one. This worked well in daylight but less so in darkness, effective to 600 meters in 25% moonlight. A special filter was added to the exterior searchlight to alleviate this issue.
The crew of a late model A2 sit atop their tank. Photo: Sabot Publications
Early model M60A2, US Army 3rd Armoured Division. Note the fume extractor on the barrel.
Later model M60A2 in MERDC (Mobility Equipment Research and Development Center) camo scheme. Note the barrel is without fume extractor.
Both Illustrations are by Tank Encyclopedia’s own David Bocquelet
Service and Failure
In total, around 520 M60A2s were built, with service in the US Army and the US Marine Corps. A study by the US Army, proposed the M60A2 operate in an “overwatch” role, in support of more traditionally armed tanks, and provide long-range anti-tank support capability from the rear.
The A2 had a short service life succumbing to the same failings of Sheridan, concerning the missile system. The designers of the missile, Ford Aeronutronic, a division of the Ford Motor Company, greatly underestimated the task of producing a fully operational Anti-Tank Guided Missile as advanced as the MGM-51. Development of the Shillelagh was awash with technical and mechanical issues, including problems with the propellant, ignition of the propellant, tracking system and the infrared command link responsible for missile guidance.
Despite its many problems, the A2 did succeed in enabling “carry-over” technology for the MBT-70 project and the later M1 Abrams Main Battle Tank. The A2 was fully removed from service by 1981. Many of the A2s had their turrets removed and replaced by M60A3 turrets. In 1985 some M60A2s were converted into engineering vehicles such as the M60A1 AVLB bridge layers or the remotely controlled Panther mine clearing vehicle.
The M60A2 is frequently referred to as the “Starship”. However, there is no official use of the name in any documentation, at least dated to when the vehicle was in service. It may well be a post-service name. It is widely believed that it bears this name due to either its highly sophisticated technology (for its time) or the non-traditional appearance of its turret.
Early model A2 taking part in training. Sabot Publications
|Dimensions (L-W-H)||30’9″ x 11’9″ x 10’7″ ft.in|
(9.43m (6.94m) x 3.63m x 3.27m)
|Total weight, battle ready||52 tons (114,640 lbs)|
|Crew||4 (commander, driver, loader, gunner)|
|Propulsion||Continental AVDS-1790-2 V12, AC TT diesel, 750 bhp (560 kW), 15.08 bhp/t|
|Transmission||General Motors, CD SD 2 fw/1 rv ranges|
|Maximum speed||30 mph (48 km/h) on road|
|Suspension||Torsion bars suspensions, shock absorbers|
|Range (fuel)||300 miles/500 km (1457 liters/385 US gal.)|
|Armament||M81E1 Rifled 152 mm Gun/Launcher: 33 HE & HEAT, 13 MGM-51 Shillelagh ATGMs|
Sec: 1 x cal .50 M85 (12.7 mm)+ 1 cal .30 (7.62 mm) Browning M73
|Armor||RHA max. 6.125 in (155 mm)|
|Total production||Aprx. 520|
|For information about abbreviations check the Lexical Index|
Links, Resources and Further Reading
R. P. Hunnicutt, Patton: A History of American Medium Tank, Presidio Publishing
Armor Magazine, January-February 1972: The Death of the Tank by Lt.Col. Warren W. Lennon.
Osprey Publishing, New Vanguard #85: M60 Main Battle Tank 1960–91
Sabot Publications, M60A2 Main Battle Tank in Detail, Volume 1
Sabot Publications, M60A2 Main Battle Tank in Detail, Volume 2
The M60A2 on Military Today