ABRAMS
M1A1/2

From the INTERNET DJ re-produces specifications of a very special tank

The M1 Abrams Main Battle tank is made by General Dynamics Land Systems (GDLS) of USA. The first M1 tank was produced in 1978, the first M1A1 in 1985 and the first M1A2 in 1986. 3,273 M1 Main Battle Tanks have been produced for the US Army. The numbers of M1A1 tanks produced are 555 co-produced with Egypt, 4,796 for the US Army and 221 for the US Marines.

The numbers of M1A2 tanks produced are 77 for the US Army, 315 for Saudi Arabia and 218 for Kuwait. For the M1A2 Upgrade Programme, 1079 M1 Abrams tanks are being upgraded to M1A2 configuration.

The Abrams accommodates a crew of four, commander, driver, gunner and loader.

M1A2 SYSTEM ENHANCEMENT PACKAGE (SEP)

GDLS are contracted to supply 240 M1A2 tanks with a system enhancement package (SEP), with deliveries starting in August 1999.

The M1A2 SEP will contain an embedded version of the US Army's Force XXI command and control architecture; new commander's display for digital colour terrain maps; under armour auxiliary power unit; second generation thermal imaging sight with increased range; and thermal management system.

The US Army has plans to procure 1150 M1A2 SEP tanks to be in service by 2004.

ARMAMENT

The main armament is the 120 mm smoothbore gun, US designation code M256, developed by Rheinmetall GmbH of Germany. The system manager for the 120 mm ammunition is Alliant Techsystems with second source by Olin Ordnance. The 120 mm gun fires the following ammunition: the 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.

The commander has a 12.7 millimetre (0.50 inch) calibre Browning M2 machine gun on a powered rotary platform and equipped with a x3 magnification sight. The elevation is from -10 to +65 degrees and the traverse is 360 degrees. The loader has a 7.62 calibre M240 machine gun on a Skate mount. The elevation of the M240 is from -30 to +65 degrees and the traverse rotation is 265 degrees. A 7.62 mm M240 machine gun is also mounted coaxially on the right hand side of the main armament.

COUNTERMEASURES

On both sides of the turret the tank is fitted with six-barrelled smoke grenade dischargers, model L8A1, designation M250. A smoke screen can also be laid by an engine operated system.

COMMANDER

The commander's station is equipped with six periscopes which provide all round 360 degree view.

The Commander's Independent Thermal Viewer (CITV) from Raytheon TI provides the commander with independent stabilised day and night vision with a 360 degree view, automatic sector scanning, automatic target cueing of the gunner's sight and back-up fire control. The magnification is x2.6 at 3.4 degrees narrow field of view and x7.7 at 10.4 degrees wide field of view.

GUNNER

The Gunner's Primary Sight- Line of Sight (GPS-LOS) has been developed by Raytheon (formerly Hughes). The system has daylight optics with x10 magnification narrow field of view and x3 field of view, and unity magnification with 18 degrees field of view. The Thermal Imaging System, TIS, has magnification x10 narrow field of view and x3 wide field of view. The thermal image is displayed in the eyepiece of the gunner's sight together with the range measurement from a Raytheon laser rangefinder. The M1A2 Abrams tank has a two-axis GPS-LOS which increases the first round hit probability by providing faster target acquisition and improved gun pointing.

The latest Eyesafe Laser Rangefinder (ELRF) has been developed by Litton Laser Systems. The upgrade is fully compliant to the original LRF requirements developed by Hughes for the Abrams tank - firing rate of 1 shot per second, range accuracy to within 10 metres and target discrimination of 20 metres. The gunner has a Kollmorgen Model 939 auxiliary sight with magnification x8 and field of view 8 degrees. The digital fire control computer is supplied by Computing Devices Canada. The fire control computer automatically takes data to calculate the fire control solution.

The data includes:

• the lead angle measurement
• the bend of the gun measured by the muzzle reference system
• wind velocity measurement from a wind sensor on the roof of the turret
• the data from a pendulum static cant sensor located at the centre of the turret roof

The operator manually inputs the data on the ammunition type and temperature, and the barometric pressure.

DRIVER

The driver's station at the centre front of the vehicle is equipped with a monitoring panel showing the condition of vehicle fluid levels, batteries and electrical equipment. 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 degrees field of view.

The Driver's Vision Enhancer (DVE), AN/VSS-5, from Raytheon TI, is based on a 328 x 245 element uncooled detector array, working in the 7.5 to 13 micron waveband. The AN/VSS-5 provides a 30 degree elevation and 40 degree azimuth field of view.

A Driver's Thermal Viewer, AN/VAS-3, from Raytheon, is installed on the M1A2 Abrams tanks for Kuwait. The AN/VAS-3 is based on a 60 element cadmium mercury telluride detector operating in the waveband 7.5 to 12 microns. The field of view is 40 degrees azimuth x 20 degrees elevation.

ENGAGEMENT

The gunner aligns the reticle in the Gunner's Primary Sight with the target. The range is determined by the laser rangefinder and the range data is transferred to the fire control computer. The gunner's sight displays a ready-to-fire indication together with symbology from the fire control computer and system operational status. The gunner checks the alignment of the reticle in the Primary Sight with the target and the ready to fire indication and fires the gun.

SURVIVABILITY

The hull and turret of the M1 are protected by advanced armour similar to the Chobam armour developed by the UK Ministry of Defence. The M1A1 tank incorporates steel encased depleted uranium armour.

The stowage for the main armament ammunition is in armoured ammunition boxes behind sliding armour doors. 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.

PROPULSION

The M1 is equipped with an AGT 1500 gas turbine engine from Lycoming Textron. The Allison Transmission, X-1100-3B, provides four forward and two reverse gears.