Type Main battle tank
Place of origin United States
Service history
Used by United States, Australia, Egypt, Kuwait, Saudi Arabia
Wars Gulf War, Iraq War
Production history
Designer Chrysler Defense
Designed 1970s
Manufacturer General Dynamics
Unit cost US$4.35 million (M1A2)[1]
Produced 1979–present
Variants M1A1, M1A2, M1A2SEP
Specifications
Weight 67.6 short tons (61.4 tonnes)
Length Gun forward: 32.04 ft (9.77 m)
Hull length: 26.02 ft (7.93 m)
Width 12 ft (3.66 m)
Height 8 ft (2.44 m)
Crew 4 (commander, gunner, loader, driver)
--------------------------------------------------------------------------------
Armor Chobham, RHA
Primary
armament 105 mm M68 rifled cannon (M1)
120 mm M256 smoothbore cannon (M1A1, M1A2, M1A2SEP)
Secondary
armament 1 x .50-caliber (12.7 mm) M2HB heavy machine gun
2 x M240 7.62 mm machine guns (1 pintle-mounted, 1 coaxial)
Engine AGT-1500C multi-fuel turbine engine
1500 hp (1119 kW)
Power/weight 24.5 hp/tonne
Transmission Allison DDA X-1100-3B
Suspension Torsion bar
Ground clearance 0.48 m (M1, M1A1)
0.43 m (M1A2)
Operational
range 465.29 km (289 mi)
With NBC system: 449.19 km (279 mi)
Speed Road: 67.72 km/h (42 mph)
Off-road: 48.3 km/h (30 mph)
[show]v • d • ePost-Cold War tanks
The M1 Abrams is a main battle tank produced in the United States. The M1 is named after General Creighton Abrams, former Army Chief of Staff and commander of the 37th Armored Regiment. It is a well armed, heavily armored, and highly mobile tank designed for modern armored ground warfare.[citation needed] Notable features of the M1 Abrams include the use of a powerful gas turbine engine, the adoption of sophisticated composite armor, and separate ammunition storage in a blow-out compartment for crew safety. It is one of the heaviest tanks in service, weighing in at close to 70 tons.
The M1 Abrams entered U.S. service in 1980, replacing the M60 Patton and M48A5. It did, however, serve for over a decade alongside the improved M60A3, which had entered service in 1978. Three main versions of the M1 Abrams have been deployed, the M1, M1A1, and M1A2, incorporating improved armament, protection and electronics. These improvements, as well as periodic upgrades to older tanks have allowed this long-serving vehicle to remain in front-line service. It is the principal combat tank of the United States Army and Marine Corps, and the armies of Egypt, Kuwait, Saudi Arabia, and as of 2007, Australia.
[edit] Background
The first attempt to replace the aging M60 series of tanks was the abortive MBT-70, developed in partnership with West Germany. The M60 Patton was itself a gradual evolution of a design starting with the World War II era M26 Pershing, with a very tall profile, and average armor and weaponry compared to the contemporary Soviet designs. The MBT-70 was very ambitious, like many American weapons programs of the 1960s. It had a gun launched missile system, kneeling suspension, a driver housed in the turret, and various other ideas that ultimately proved unsuccessful. Cancellation of this project paved the way for the much more successful M1 Abrams tank, which did not incorporate most of the troublesome innovations tried by the MBT-70.
[edit] Development
The M1 Abrams was designed by Chrysler Defense (in 1979, General Dynamics Land Systems Division purchased Chrysler Defense Division) and is currently produced by General Dynamics Corporation in Lima, Ohio, and first entered US Army service in 1980. An improved version of the M1, the M1A1, was introduced in 1985. The M1A1 has the M256 120 mm smoothbore cannon developed by Rheinmetall AG of Germany for the Leopard 2, improved armor, and a CBRN protection system. The M1A2 is a further improvement of the M1A1 with a commander's independent thermal viewer and weapon station, position navigation equipment, digital data bus and a radio interface unit. The M1A2 SEP-(System Enhancement Package) added digital maps, FBCB2-(Force XXI Battlefield Command Brigade and Below) capabilities, and an improved cooling system to maintain crew compartment temperature with the addition of multiple computer systems to the M1A2 tank.
A left front view of the XM1 Abrams tank, which replaced the M60 series, during a demonstration on the test range in 1979.Further upgrades include depleted uranium armor for all variants, a system overhaul that returns all A1s to like-new condition (M1A1 AIM), a digital enhancement package for the A1 (M1A1D), a commonality program to standardize parts between the U.S. Army and the Marine Corps (M1A1HC) and an electronic upgrade for the A2 (M1A2 SEP).
During Operations Desert Shield and Desert Storm and for Bosnia, some M1A1s were modified with armor upgrades. The M1 can be equipped with mine plow and mine roller attachments if needed. The M1 chassis also serves as a basis for the Grizzly combat engineering vehicle and the M104 Wolverine heavy assault bridge.
Over 8,800 M1 and M1A1 tanks have been produced at a cost of $2,350,000–$4,300,000 per unit, depending on the variant.
[edit] Design features
[edit] Armor
Tankers of the 1st Armored Division drive an M1 Abrams tank through the Taunus Mountains north of Frankfurt during Exercise Ready Crucible on February 14, 2005.The Abrams is protected by Chobham armor, a further development of British "Burlington" armor. Chobham is a composite armor formed by spacing multiple layers of various alloys of steel, ceramics, plastic composites, and kevlar, giving an estimated maximum (frontal turret) 1320-1620 millimeters of RHAe versus HEAT (and other chemical energy rounds) and 940-960 mm versus kinetic energy penetrators.[2] It may also be fitted with reactive armor over the track skirts if needed (as in the Urban Survival Kit) and Slat armor over the rear of the tank and rear fuel cells to protect against ATGMs. Fuel and ammunition are in armored compartments with blowout panels to protect the crew from the risk of the tank's own ammunition cooking off if the tank is damaged. Protection against spalling is provided by a kevlar liner. Beginning in 1987, M1A1 tanks received improved armor packages that incorporated depleted uranium (DU) mesh in their armor at the front of the turret and the front of the hull. Armor reinforced in this manner offers significantly increased resistance towards all types of anti-tank weaponry, but at the expense of adding considerable weight to the tank.
The first M1A1 tanks to receive this upgrade were tanks stationed in Germany, since they were the first line of defense against the Soviet Union. US-based tank battalions participating in Operation Desert Storm received an emergency program to upgrade their tanks with depleted uranium armor immediately before the onset of the campaign. M1A2 tanks uniformly incorporate depleted uranium armor, and all M1A1 tanks in active service have been upgraded to this standard as well, the armor thickness is believed to be equivalent to 24 inches (610 mm) of RHA. The strength of the armor is estimated to be about the same as similar western, contemporary main battle tanks such as the Leopard 2. The M1A1/M1A2 can survive multiple hits from the most powerful tank munitions (including 120 mm depleted uranium APFSDS) and anti-tank missiles.[citation needed] In the Persian Gulf War, Abrams tanks survived multiple hits at relatively close ranges from Iraqi T-72s and ATGMs. M829A1 "Silver Bullet" APFSDS rounds from other M1A1 Abrams were unable to penetrate the front and side armor (even at close ranges) in friendly fire incidents as well as an incident in which another Abrams tried to destroy an Abrams that got stuck in mud and had to be abandoned.[3]
In addition to the advanced armor, some Abrams, are equipped with a Missile Countermeasure Device that can impede the function of guidance systems of semiactive control line-of-sight (SACLOS) wire and radio guided anti-tank guided missiles (Russian AT-3, AT-4, AT-5, AT-6 and the like) and thermally and infrared guided missiles. (ATGM)[2]. This device is mounted on the turret roof in front of the Loader's hatch, and can lead some people to mistake Abrams fitted with these devices for the M1A2 version, since the Commander's Independent Thermal Viewer on the latter is mounted in the same place, though the MCD is box-shaped and fixed in place as opposed to cylindrical and rotating like the CITV.
In the chance that the Abrams does suffer damage resulting in a fire in the crew compartment, the tank is equipped with a halon fire-suppression system that automatically engages and extinguishes fires in seconds.
[edit] Armament
U.S. Marine M1A1 firing in Najaf Province, Iraq during a training exercise.
[edit] Main armament
M68A1 rifled gun
The main armament of the original model M1 was the M68A1 105 mm rifled tank gun firing a variety of high explosive anti-tank (HEAT), high explosive, white phosphorus, and a highly efficient and lethal anti-personnel (multiple flechette) round. This gun is a license-built version of the British Royal Ordnance L7 gun. While being a reliable weapon and widely used by both NATO and former Warsaw Pact nations alike, a cannon with lethality beyond the 3 kilometer range was needed to combat newer armor technologies. To attain that lethality, projectile diameter needed to be increased. The M68A1's performance in terms of accuracy and armor-piercing penetration is on par with the M256A1 up to 3000 meters out, but beyond that range the 105mm projectile lacks the kinetic energy to defeat modern armor packages.
M256 smoothbore gun
Washington Army National Guard soldier from 81st Armor Brigade, sets the sights on the main gun of an M1A1 Abrams in Mosul, Iraq in January 2005.The main armament of the M1A1 and M1A2 is the M256A1 120 mm smoothbore gun, designed by Rheinmetall AG of Germany. The M256A1 is a variant of the Rheinmetall 120 mm L/44 gun carried on the German Leopard 2 on all variants up to the Leopard 2A5. Leopard 2A6 replaced the L/44 barrel with a longer L/55. The newer M256A1 is manufactured under license in the United States by Watervliet Arsenal, New York.
The M256A1 fires a variety of rounds. The M829A2 was developed specifically to address the threats posed by a Soviet T-90 or T-80U tank equipped with kontakt-5 Explosive Reactive Armor. It also fires HEAT shaped charge rounds such as the M830, the latest version of which (M830A1) incorporates a sophisticated multi-mode electronic sensing fuse and more fragmentation which allows it to be used effectively against armored vehicles, personnel, and low-flying aircraft. Unlike the Soviet-built tanks it was designed to go up against, the Abrams uses a manual loader rather than an automatic device, due to the belief that having a person reload the gun is faster and more reliable. This decision was proven out as the Soviet-era automatic loading system proved troublesome.[citation needed] Also important in the decision to use a crew member instead of an automatic loader during the XM-1 development was the fact that autoloaders of the day did not allow for separate ammunition storage in the turret.
[edit] The Iraq war
M1A1 Abrams from A Company, Task Force 1st Battalion, 35th Armor Regiment, 2nd Brigade Combat Team, 1st Armored Division, pose for a photo under the "Hands of Victory" in Ceremony Square, Baghdad, Iraq.Further combat was seen during 2003 when US forces invaded Iraq and deposed the Iraqi leader Saddam Hussein. The campaign saw very similar performance from the tank with no Abrams crew member being lost to hostile fire during the battle in Iraq, mainly due to unopposed air-support. However, several tanks were destroyed due to secondary effects from enemy weapons. Abandoned Abrams were destroyed by friendly fire to prevent recovery of vehicle or technology. Damages by 25 mm AP-DU, anti-armor RPG fire and 12.7 mm rounds was encountered. But on no occasion anti-tank guided weapons or anti-tank mines struck the US MBTs.[26]
The most lopsided achievement of the M1A2s was the destruction of seven T-72 Lion of Babylon tanks in a point-blank skirmish (less than 50 yards) near Mahmoudiyah, about 18 miles (29 km) south of Baghdad, with no losses for the American side.[27] However, on October 29, 2003, two soldiers were killed and a third wounded when their tank was disabled by an anti-tank mine, which was combined with other explosives (500 kg, including several 155 mm rounds) to increase its effect. The massive explosion beneath the tank knocked off the turret. This marked the first time deaths resulted from a hostile-fire assault on the M1 tank from enemy forces. Following lessons learned in Desert Storm, the Abrams and many other US combat vehicles used in the conflict were fitted with Combat Identification Panels to reduce friendly fire incidents. These were fitted on the sides and rear of the turret, with flat panels equipped with a four-cornered 'box' image on either side of the turret front (the latter of which can be seen in the above image, similar flat panels also being employed on British Challenger 2 tanks serving in the conflict). In addition to the Abrams' already-formidable armament, some crews were also issued M136 AT4 shoulder-fired anti-tank rockets under the assumption that they might have to engage heavy armor in tight urban areas where the main gun couldn't be brought to bear. Some Abrams were also fitted with a secondary storage bin on the back of the existing bustle rack on the rear of the turret referred to as a bustle rack extension to enable the crew to carry more supplies and personal belongings.
During the major combat operations in Iraq, Abrams crew members were lost when one tank of the US Army's 3rd Infantry Division, and US Marine Corps troops, drove onto a bridge. The bridge collapsed, dropping the tank into the Euphrates River, where four Marines drowned.
A destroyed USMC M1A1 Abrams rests in front of a Fedayeen camp just outside of Jaman Al Juburi, Iraq on April 6, 2003.During an early attack on Baghdad, one M1A1 was disabled by a recoilless rifle round that had penetrated the rear engine housing, and punctured a hole in the right rear fuel cell, causing fuel to leak onto the hot turbine engine. After repeated attempts to extinguish the fire, the decision was made to destroy or remove any sensitive equipment. Oil and .50 caliber rounds were scattered in the interior, the ammunition doors were opened and several thermite grenades ignited inside. Another M1 then fired a HEAT round in order to ensure the destruction of the disabled tank. The tank was completely disabled but still intact. Later, an AGM-65 Maverick and two AGM-114 Hellfire missiles were fired into the tank to finish its destruction. Remarkably, the tank still appeared to be intact from the exterior.[28]
M1A1 conducts reconnaissance in Iraq on Sept. 6, 2004.On November 27, 2004 an Abrams tank was badly damaged from the detonation of an extremely powerful improvised explosive device (IED). The IED consisted of three M109A6 155 mm shells, with a total explosive weight of 34.5 kg, that detonated next to the tank. The tank's driver received lethal injuries from shrapnel. The other three crew members were able to escape.
On December 25, 2005 another M1A2 was disabled by an explosively formed penetrator IED. The IED penetrated through a road wheel, and hit the fuel tank, which left the tank burning near central Baghdad. One crew member, Spc. Sergio Gudino, died in the attack.
On June 4, 2006 two of the four soldiers in an Abrams crew died in Baghdad, when an IED detonated near their M1A2.
Some Abrams were disabled by Iraqi infantrymen in ambushes employing short-range antitank rockets, such as the Russian RPG-7, during the 2003 invasion. Although the RPG-7 is unable to penetrate the front and sides, the rear and top are vulnerable to this weapon. Frequently the rockets were fired at the tank tracks. Another was put out of action in an incident when fuel stowed in an external rack was struck by heavy machine gun rounds. This started a fire that spread to the engine.[3] [4].
There have also been a number of Abrams crewmen killed by sniper fire during times when they were exposed through the turret hatches of their tanks. Some of these attacks were filmed by insurgents for propaganda purposes and spread via the Internet. One of these videos shows a large IED detonating beneath an Abrams and nearly flipping the vehicle, though the tank landed back on its treads and appeared to have suffered no serious damage as it was still mobile and traversing the turret following the attack.
[edit] Variants and upgrades
An M1A1 Abrams tank from 1st Tank Battalion, 1st Marine Division, breaches the obstacle belt with a mine plow during an amphibious assault in 1997.
Grizzly.XM1 Experimental model. Nine test-beds were produced in 1978.
M1 First production variant. Production began in 1979 and continued to 1985 (3,273 build for US).
M1IP (Improvement Production). Produced briefly in 1984 before the M1A1, contained upgrades and reconfigurations.
M1A1 Production started in 1986 and continued to 1992 (4,976 build for US, 221 for USMC, 755 for Egypt, 59 M1A1 AIM SA sold to Australia).
M1A1HC (Heavy Common) added new depleted uranium armor mesh, pressurized NBC system, rear bustle rack for improved stowage of supplies and crew belongings, and M256 120 mm smoothbore cannon.
M1A1-D (Digital) A digital upgrade for the M1A1HC, to keep up with M1A2 SEP.
M1A1-AIM (Abrams Integrated Management) A program whereby older units are reconditioned to zero hour conditions.[5] 59 M1A1 AIM SA have been sold to Australia.
M1A1 KVT (Krasnovian Variant Tank) M1A1's that have been visually modified to resemble Soviet-made tanks for use at the National Training Center, fitted with MILES gear and a Hoffman device.
M1A2 (Baseline) Production began in 1992 (77 build for US and more than 600 M1s upgraded to M1A2, 315 for Saudi Arabia, 218 for Kuwait).
M1A2 SEP (System Enhancement Package) Also with upgraded 3rd generation depleted uranium encased armor with graphite coating (240 new build, 300 M1A2s upgraded to M1A2SEP for the USA, 250 for Egypt in 2 Egyptian co-production batches of 125 each).
M1 Grizzly Engineer Vehicle [6]
M1 Panther II Remote Controlled Mine Clearing Vehicle[7]
M104 Wolverine Heavy Assault Bridge[8]
M1 Panther II Mine Clearing Blade/Roller System.
M1 Assault Breacher Vehicle.
M1 Armored Recovery Vehicle. Only a prototype produced.
[edit] Specifications of variants
M1 M1IP M1A1 M1A2 M1A2 SEP
Length 32.04 ft (9.77 m)
Width 12 ft (3.7 m)
Height 7.79 ft (2.37 m) 8.0 ft (2.44 m)
Top speed 45 mph (72 km/h) 41.5 mph (67 km/h) 42 mph (68 km/h)
Range 310 mi (498 km) 288 mi (465 km) 243 mi (391 km)
Weight 61.4 tons (55.7 tonnes) 62.8 tons (57.0 tonnes) 67.6 tons (61.3 tonnes) 68.4 tons (62.1 tonnes) 69.5 tons (63.0 tonnes)
Main armament 105 mm M68 rifled 120 mm M256 smoothbore
Crew 4 (commander, gunner, loader, driver)
Note: All of the above produce a power of 1500 hp (1119 kW).
