Crew: 4 (Commander, Gunner, Loader & Driver).
Combat Weight: 58,500 kg (58.5 tonnes).
Power-to-Weight Ratio: 23.93 hp/ton.
Ground Pressure: 0.84 kg/cm2.
Length: 10.194 metres.
Width: 3.847 metres.
Height: 2.32 metres.
Ground Clearance: 0.45 metres.
Maximum Speed: 72 km/h (45 mph) - road.
.......................40 km/h (25 mph) - cross-country.
Maximum Range: Un-refuelled range in combat; 450 km (280 miles) - estimate.
Maximum Fuel Capacity: 1610 litres.
Gradient: 77º.
Slide Slope: 40%.
Vertical Obstacle: 0.9 metres.
Trench Crossing: 2.43 metres.
Shallow Fording: 1.4 metres.
Engine: Prototype variants are fitted with a MTU 838 Ka-501 (from Germany) 10-cylinder, liquid-cooled, diesel producing 1400 hp @ 2400 RPM. Production variants will reportedly be fitted with a locally-designed engine developing 1500 hp.
Transmission: Prototype variants have a semi-automatic transmission (from Germany) with 4 forward and 2 reverse gears. Renk Epicyclic with hydrodynamic torque converter. Production variants will have a locally designed semi-automatic transmission, hydrodynamic torque converter, retarder and integral system.
Suspension: Hydro-pneumatic. The aluminium alloy rubberised track blocks have rubber-bushed pins, the track tensioners have a built-in overload protection.
Steering: Double radii, mechanical steering with neutral turn.
Brakes: Hydraulically operated high performance disc brake that is incorporated into the final drive.
Electrical System: Not known.
Armament: 1 x 120mm rifle bore, electro-slag refined main gun with 39 rounds (HE, HEAT, HESH, APFSDS and smoke).
...............1 x 12.7mm anti-aircraft machine gun with 1000 rounds - estimate.
...............1 x 7.62mm co-axial machine gun with 3000* rounds - estimate.
Fire Control System: Bharat Electronics AL-4421 Mk.1B Digital FCS.
Turret Power Control: Electro-Hydraulic / Manual.
Gun Elevation/Depression: +20/-10º.
Gun Stabiliser: Vertical / Horizontal.
Rangefinder: Laser from Barr & Stroud Ltd., with a reported range of 10 km.
Smoke Grenade Launchers: Nine forward-firing smoke grenade discharges, mounted on either side of the turret, with the upper layer having five tubes and the lower layer having four.
Projected Variants: Engineer Tank
..........................Artillery Support
..........................Observation Post Vehicle
..........................Armoured Recovery Vehicle
..........................Air Defence (Gun or Missile)
..........................Armoured Vehicle Launched Bridge
Features of the Arjun Mk.1 MBT
The integrated digital fire control system installed in the Arjun Mk.1 MBT consists of a laser rangefinder, ballistic computer, thermal imaging night sight, meteorological sensor, stabilised panoramic sight for the tank commander, stand-by (articulated) sighting telescope, GPS and an electronic gate to ensure a first round hit probability. The third generation director type, fire control system with a 120mm gun electronically slaved to the sights, enables the gunner to locate, identify, track, range and engage moving targets while its moving. This gives a high first round hit probability. The gunner's main sight consists of a day sight, thermal sight, laser rangefinder and stabilised head common, to all three channels. The common sighting head mirror is stabilised in elevation and azimuth. The day sight has dual magnification while the thermal imager provides a night vision facility to the gunner and the commander to observe and engage targets under conditions of total darkness and smoke. The laser rangefinder is integral with the gunner's sight.
The panoramic sight enables the commander to effect an all-round surveillance on the battlefield without moving his eyes from the sight and without being disturbed by the motion of the turret. The field of view is stabilised with the help of a two-axis rate gyro mounted on the platform of the head mirror. The sight has dual magnification. The ballistic computer, computes the gun laying data based on information provided by a number of sensors mounted in the vehicle and on manual inputs and provides the signals corresponding to the tangent elevation and azimuth offset. To increase the accuracy of the firing, the fire control system has a coincidence window that allows firing of the main armament only when it reaches the desired position as dictated by the computer. The 120mm rifled gun will fire APFSDS (Armour Piercing Fin Stabilized Discarding Sabot), HESH (High-Explosive Squash Head), HE (High-Explosive), HEAT (High-Explosive Anti-Tank) and smoke rounds. A special 120mm anti-helicopter round is under development as well. All 120mm rounds use a semi combustible cartridge case.
The 120mm rifled gun is made of ESR steel and is fitted with a thermal sleeve and a fume extractor. The thermal sleeve prevents irregular temperature distribution on to the tube due to the weather influences. A new high energy propellant is used in the 120mm rifled gun to give a higher muzzle velocity and therefore greater penetration characteristics. A 7.62mm machine gun is coaxial with the main armament and a 12.7mm AA machine gun is fitted for anti-aircraft defence. Production Arjun MBTs will also have a new composite laminate armour called Kanchan. This will be produced by Mishra Dhatu Nigam Limited (MDNL). The tank also has a NBC (Nuclear-Biological-Chemical) system that is designed & built by BARC and a night vision device built by IRDE. To further enhance combat survivability, the tank has an auto-fire detection & suppression system. Ammunition is also stowed in water tight containers to reduce the risk of fire.
