Main Battle Tank (MBT)
Despite origins reaching back some three decades, the M1 Abrams remains a proven frontline performer for the American military and others.
Authored By: Staff Writer | Last Edited:
The M1 Abrams was designed by Chrysler Defense and produced under the General Dynamics brand. The tank was introduced in 1979, entered service in 1980 and is still undergoing production. The system has been featured in the 1991 Gulf War and Bosnia along with the US invasions of Afghanistan in 2001 and Iraq in 2003. Along with the United States, operators of the Abrams include Australia, Egypt, Kuwait and Saudi Arabia. As of this writing, roughly 8,800 Abrams have been produced in all its varied forms. In US military operations, the Abrams currently serves with both the US Army and the US Marine Corps.
The origins of the M1 Abrams can be traced back to a failed partnership between the United States and West Germany in producing a new generation main battle tank system with the latest capabilities to combat whatever the Soviets were brewing (this turned out to be the T-72). The US Army was then fielding the M60 Patton series (its own origins lay in the World War 2-era M26 Pershing heavy tank) as their main battle tank and it was largely believed that the T-72 would outclass the Patton as soon as it arrived - likewise for the West Germans and their post-war Leopard 1 main battle tanks. The joint design became known as the MBT-70.
The MBT-70 offered a low profile with a powerful main gun (152mm coupled to an XM-150 autoloader for the American model and an auto-loading 120mm Rheinmetall gun for the German model). The turret was sloped on all sides and set in the middle of the design and housed the entire crew (the remarkably low silhouette - at just over 6 feet tall - necessitated that the driver be placed in the turret with the tank commander and gunner). With the autoloader, operation of the MBT-70 required the use of only three personnel similar to Russian auto-loading MBTs. The hull was sloped towards the front, flat-faced at the rear engine compartment and showcased barely any surface exposure along the sides above the tracks. A 20mm cannon could be used in the air defense role, this springing up from behind the driver's cupola. A 7.62mm co-axial machine gun mount was standard on the MBT-70, and on any tank since World War 2 for that matter. The profile of the MBT-70 was characterized by its medium-sized road wheels with six fitted to a side. The American version of the MBT-70 would have fired a barrel-launched Shillelagh anti-tank missile at long ranges. Suspension was of an advanced hydropneumatic type that was fully adjustable on-the-fly by the driver. Despite it being a heavy 50+ ton tank design, the MBT-70 was reportedly able to reach an unheard of maximum speed of 52 miles-per-hour.
As the budget for the MBT-70 project rose widely out of control - both parties naturally developed different ideas as to the design direction of this new tank - the West Germans eventually dropped out of support for the program and instead poured their resources into producing a follow-up design to their successful Leopard 1 main battle tank, with the new design eventually becoming the equally potent Leopard 2. By 1971, the American Congress saw the ballooning MBT-70 project coming to naught and reinvested those funding dollars towards a program that would ultimately produce the M1 Abrams. The MBT-70 project, despite its revolutionary design implements, proved too ambitious and was effectively killed by the congressional decision.
The XM1 Abrams prototype was designed by Chrysler Defense. General Dynamics Land Systems Division subsequently purchased Chrysler Defense Division in 1979. The XM1 fitted the British Royal Ordnance L7 series rifled main gun of 105mm, a license-production copy built in the United States. The XM1 entered production as the M1 Abrams in 1979 and became operational the following year. The Abrams featured state-of-the-art armor protection for the crew complete with armored compartments for fuel and ammunition stores. Crew accommodations were for four personnel and consisted of the tank commander, gunner, loader and driver. The new tank weighed in at 67.5 short tons making it one of the heaviest such systems in the world.
After a short time in service, it was already becoming apparent that the 105mm rifled British armament would not stay up to the conventional tank standards being fielded in the East. As such, the Abrams was upgunned to incorporate the German-produced Rheinmetall AG 120mm smoothbore cannon known in the US inventory by the designation of M256. The Abrams was now produced under the M1A1 designation and appeared in 1986 with production running through 1992. Additional upgrades included improved armor allocation and the Chemical, Biological, Radiological and Nuclear (CBRN) protection system.
The M1A1 was soon followed by the improved M1A2. The A2 featured a revised weapon station for the tank commander incorporating the latest in digital systems, a separate thermal viewer system and improved navigation equipment. The M1A2 SEP (System Enhancement Package) brought the Abrams up to an even higher technological standard, incorporating digital maps, additional processing computers to handle the digital workflow and an improved cooling system. Depleted uranium armor was also part of follow-on upgrades while other subsequent upgrade programs have produced the M1A1 AIM, M1A1D, M1A1HC and the M1A2 SEP. Reactive armor and slat armor became optional and were offered as part of the Tank Urban Survival Kit (TUSK) developed for urban fighting - where conventional ranged tank engagement rules effectively fly out of the window.
Seating in the Abrams in conventional by Western standards with the driver seated at the center front of the hull, just under the main gun base (that is if the turret is facing directly forward). The tank commander, loader and gunner take their stations in the fully 360-degree traversable turret with the gunner seated ahead of the tank commander and the loader to the tank commander's immediate left. The tank commander and the loader are each afforded their own hatch and defensive machine gun weaponry. Design of these hatches is such that the weapons can be fired from within the turret without exposing either crewmember to the enemy. The Abrams sports British-designed Chobham RHA steel-encased depleted uranium mesh plating for its crew and vital systems. Chobham makes use of various alloys made up of kevlar, ceramics, plastic composites and steel to achieve a near-perfect blend of anti-penetration surfaces. Power is derived from a Honeywell AGT1500C multi-fuel turbine engine developing 1,500 horsepower mated to an Allison DDA X-1100-3B transmission. Specifications include a top road speed of 42 miles per hour and a top off-road speed of 30 miles per hour - in this respect, it was not uncommon to hear Abrams tank crews describe their mount as the "Cadillac of tanks". The power-to-weight ratio is listed at 24.5 hp/metric ton while suspension is accomplished through use of a torsion bar assembly. Range is reportedly limited to 289 miles.
Armament for the Abrams series began with the British M68 rifled cannon of 105mm but, as mentioned earlier, this was "upgunned" to the standard M256 smoothbore 120mm system thereafter, with this armament covering the M1A1, M1A2 and the M1A2SEP variants and applicable upgrades. Secondary armament came in the form of a Browning M2HB 12.7mm anti-aircraft heavy machine gun operated by the tank commander through his cupola. Armament was further enhanced by the addition of 2 x 7.62mm self-defense, anti-infantry M240 machine guns, one mounted co-axially in the turret alongside the main gun and another fitted on a pintle mounting at the loaders hatch. The co-axial mount is operated via the main gun controls. The loader's machine gun can be fitted with night vision equipment and extra shielding - the latter obviously for increased protection if the crewmember need to expose his upper body when firing the loader's M240.
As standard, the M1 can fire High-Explosive Anti-Tank (HEAT), HEAT shaped charged, high explosive, shotgun-type anti-personnel and white phosphorous projectile munitions as needed. The XM1111 is a cannon-fired "guided" projectile currently in development and will most likely be used by the Abrams series.
Despite entering service in 1980, the Abrams did not received her combat baptism until the 1991 Gulf War. The Abrams stacked up extremely well against the Soviet-developed T-55, T-62 and the latest T-72 offerings. One of the biggest drawbacks of the Iraqi tanks was their poor or non-existent night vision equipment and equally poor-to-adequate training. Lack of an effective air support did little to help out the Iraqi cause as well. Only 23 Abrams were lost in the ensuing battles. One of the biggest benefits of the Abrams system lay in the range of its main guns which out-shot Iraqi tanks by at least 500 meters. In fact, it seemed that friendly fire incidents were a bigger threat to the Abrams than were the Iraqi main battle tank and anti-tank weapon systems.
The Abrams was not completely done in Iraq, however, for the invasion of 2003 invasion of Iraq - organized under Operation Iraqi Freedom - saw similar tank-versus-tank results in favor of the Abrams. Though 80 or so Abrams tank systems were knocked out of action on the part of Iraqis, the Abrams still enjoyed its superior technological edge coupled with better crew training and well-developed tactics (along with an overly effective air support element). Follow-up fighting saw several Abrams damaged via Soviet-designed RPG-7 rocket propelled grenade weapons fired at the tank tracks, the tank rear and along the turret top - the three most vulnerable ballistic points of any tank, especially in the realm of urban fighting where elevations now play an advantage to the defensive party.
As with any other expensive yet successful armor series, the chassis of the Abrams continues to make up the main component of other battle-worthy systems. These include the M1 Grizzly Combat Mobility Vehicle, the M1 Panther II Remote Controlled Mine Clearing Vehicle, the M104 Wolverine Heavy Assault Bridge, the M1 Panther II Mine Clearing Blade/Roller System, the M1 Assault Breacher Vehicle and the M1 Armored Recovery Vehicle (single prototype). The Abrams tank itself can be converted to operate a mine plow and mine roller for mine-clearing services.
The Abrams is named after former Army Chief of Staff General Creighton Abrams whom served in the Vietnam War from 1968 to 1972 as Commander of US Military Forces. The M1 was designed to replace the venerable M60 Patton series, though the two ended up serving side by side for some 10 years. A single Abrams can carry a price tag of up to $4.35 million USD or more depending on the model and variant.
At any length, the Abrams should see continual frontline service for the United States and its allies for some time to come. Modernization programs obviously have kept the system relevant on today's battlefields. Power, survivability, lethality and technology have all gone a long way into creating the optimal legacy for the M1 Abrams.