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Tanks - The M1A1/2 Abrams


The M1A1/2 Abrams main battle tank is manufactured by General Dynamics Land Systems (GDLS). The first M1 tank was produced in 1978, the M1A1 in 1985 and the M1A2 in 1986.
The first M1 Abrams battle tanks were delivered to the US Army in 1980. In all 3,273 M1 tanks were produced for the US Army, 4,796 M1A1 tanks were built for the US Army, 221 for the US Marines and 880 co-produced with Egypt.
Approximately 77 M1A2 tanks were built for the US Army, 315 for Saudi Arabia and 218 for Kuwait.
For the M1A2 upgrade programme, more than 600 M1 Abrams tanks were upgraded to M1A2 configuration at the Lima Army tank plant between 1996 and 2001. Deliveries began in 1998.

M1 Abrams armament

The main armament is the 120mm M256 smoothbore gun, developed by Rheinmetall Waffe Munition GmbH of Germany. The 120mm gun fires the following ammunition - M865 TPCSDS-T and M831 TP-T training rounds, the M8300 HEAT-MP-T and the M829 APFSDS-T which includes a depleted uranium penetrator. Textron Systems provides the Cadillac Gage gun turret drive stabilisation system.
The commander has a 12.7mm Browning M2 machine gun and the loader has a 7.62mm M240 machine gun. A 7.62mm M240 machine gun is also mounted coaxially on the right hand side of the main armament.

Depleted uranium armour

The M1A1 tank incorporates steel-encased depleted uranium armour. Armour bulkheads separate the crew compartment from the fuel tanks.
The top panels of the tank are designed to blow outwards in the event of penetration by a HEAT projectile. The tank is protected against nuclear, biological and chemical (NBC) warfare.
One L8A1 six-barrelled smoke grenade discharger is fitted on each side of the turret. A smoke screen can also be laid by an engine-operated system.
In August 2006,GDLS was awarded a contract to produce 505 tank urban survivability kits (TUSK) for the US Army Abrams tanks.
TUSK includes add-on reactive armour tiles, loader's armour gun shield (LAGS), tank infantry phone (TIP), Raytheon loader's thermal weapon sight with Rockwell Collins head-mounted display and BAE Systems thermal driver's rear-view camera (DRVC). TUSK entered service on M1A1 / M1A2 tanks in late 2007 and was deployed to Iraq.
Australian M1A1 tanks are fitted with Saab Barracuda multispectral camouflage systems which reduce the tank's visual, radar and infra-red signature.

Fire control and observation

The commander's station is equipped with six periscopes, providing a 360° view. The Raytheon commander's independent thermal viewer (CITV) provides the commander with independent stabilised day and night vision with a 360° view, automatic sector scanning, automatic target cueing of the gunner's sight and back-up fire control.
The M1A2 Abrams tank has a two-axis Raytheon gunner's primary sight - line of sight (GPS-LOS) which increases the first round hit probability by providing faster target acquisition and improved gun pointing.

The thermal imaging system (TIS) has magnification ×10 narrow field of view and ×3 wide field of view. The thermal image is displayed in the eyepiece of the gunner's sight together with the range measurement from a laser range finder.
The Northrop Grumman (formerly Litton) Laser Systems eyesafe laser range finder (ELRF) has a range accuracy to within 10m and target discrimination of 20m. The gunner also has a Kollmorgen Model 939 auxiliary sight with magnification ×8 and field of view 8°.
The digital fire control computer is supplied by General Dynamics - Canada (formerly Computing Devices Canada).
The fire control computer automatically calculates the fire control solution based on - lead angle measurement, bend of the gun measured by the muzzle reference system, velocity measurement from a wind sensor on the roof of the turret and data from a pendulum static cant sensor located at the centre of the turret roof.
The operator manually inputs data on ammunition type, temperature and barometric pressure.
The driver has either three observation periscopes or two periscopes on either side and a central image intensifying periscope for night vision. The periscopes provide 120° field of view.
The DRS Technologies driver's vision enhancer (DVE), AN/VSS-5, is based on a 328×245 element uncooled infra-red detector array, operating in the 7.5 to 13 micron waveband. A Raytheon driver's thermal viewer, AN/VAS-3, is installed on the M1A2 Abrams tanks for Kuwait.

Propulsion

The M1 is equipped with a Honeywell AGT 1500 gas turbine engine. The Allison X-1100-3B transmission provides four forward and two reverse gears.
The US Army has selected Honeywell International Engines and Systems and General Electric to develop a new LV100-5 gas turbine engine for the M1A2. The new engine is lighter and smaller with rapid acceleration, quieter running and no visible exhaust.