Arjun Mark I - Design

There are three variants of this tank, Arjun Mk-I, Arjun Mk-IA, and Arjun Mk-II. Arjun Mk I can be recognized by its box-type design. The first "Arjun" (named after a mythical Hindu warrior prince) concept was laid out in 1974 by the Combat Vehicles Research and Development Establishment (CVRDE) of the Defence Research and Development Organization (DRDO). Based on 1971 battlefield experiences, the Arjun would have a locally-designed, rifled 120mm main gun, a German, MTU-based diesel powerplant (The Indians consider turbine engines fuel guzzlers), and a computerized fire control system with a laser rangefinder.

MBT Arjun is the state-of-art main battle tank designed and developed by Combat Vehicles Research and Development Establishment(CVRDE), Avadi along with other DRDO and industrial partners. MBT Arjun is provided with excellent mobility, superior fire power and protection and the features are quite comparable to contemporary world tanks. The Kanchan Armour, Hydro-pneumatic suspension, Armament system, Integrated Fire Detection & Suppression System, system engineering and system integration of complex weapon platforms are some of the significant indigenous technologies of Arjun, developed by DRDO labs.

The superior armor defeating capability of the indigenously developed Fin Stabilised Armour Piercing Discarding Sabot ammunition and 120 mm caliber rifled gun give MBT Arjun an edge over contemporary world tanks. A computer-controlled integrated fire control system incorporating day-cum-night stabilised sighting system guarantees a very high first round hit probability and reduced reaction time to bring effective fire on targets. All round protection from anti-tank ammunition is achieved by the newly developed Kanchan armour to a degree much higher than available in present generation tanks. The Arjun was to be the mainstay of the Indian Army.

Considered comparable to the M1A2 Abrams, Leopard 2, and Leclerc, the 59-ton "15th Variant" can achieve a maximum speed of 70 kph (55 mph) and cross-country speed of 40 kph with its 1400-hp powerplant. The 1,610-liter fuel tank allows for a cruising range of 200 km (120 miles). To ensure crew survivability, production versions will have the indigenously-researched and developed 'Kanchan' composite armor, an automatic fire detection and suppression system, and an NBC protection system designed and built by the Bhabha Atomic Research Center.

The rifled 120mm gun, which includes a muzzle reference system, is made of ESR steel and is fitted with a thermal sleeve and fume extractor. All main gun rounds use a semi-combustible cartridge case with increased energy propellant for higher muzzle velocity and greater penetration characteristics. In addition to the usual suite of rounds, an anti-helicopter round is under development as well. The Arjun's fire control system includes a laser rangefinder, ballistic computer, thermal imaging night sight, stabilized panoramic sight for the tank commander, and a secondary telescopic sight. The LRF (integral to the gunner's sight) has a range of nearly 10 km and a thermal imager (which can "see"' at around 5.5 km, recognize a target at 3.1 km and identify targets at 2.5 km). The Arjun fire control system's ability to fire on the move during the night is a major step forward for Indian armored forces.

The Chassis and Automative System of MBT Arjun comprises main chassis, power pack (1400 HP engine coupled to hydromech transmission), running gear with hydropneumatic suspension, integrated fuel system, advanced electrical system and other dedicated special systems like integrated fire detection and suppression system. The chassis is fabricated from rolled homogenous armour plate using advanced welding technique. Frontal armour is of Kanchan composite sandwitched between armour plates. This fully integrated Arjun chassis and Automative System having smooth riding characteristics can be used as a mobile platform for any advanced weapon system. An extremely effective hydropneumatic suspension system has been developed for MBT Arjun. The suspension is externally mounted and provides vehicle springing and damping. It consists of one bogey wheel pair for each suspension station. Gaseous medium in the hydropneumatic suspension is for all terrain maneuverability for exploiting the power available. Casing and hub of the hydropneumatic suspension are sealed for preventing dust ingression and water seepage into the casing during operation in marshy area or shallow/medium fording. The MBT Arjun is fitted with double-pin steel track with detachable rubber pads. It is made out of steel casting having two bores for insertion of rubberised pins. It is an integral piece incorporating guide horns and has got a provision for insertion of detachable pads. The end connectors are induction-hardened in the area which comes in contact with the sprocket teeth to prevent wear.

The integrated fire and explosion suppression system developed for MBT Arjun is based on state-of-the-art technology. The indigenous development of this system is considered to be a breakthrough in the field of fire protection engineering. It is capable of suppressing hydrocarbon fuel fire/explosion resulting from an enemy hit on the tank or due to any malfunctioning of the engine, transmission or any electrical short circuiting. The system is based on infra-red detectors for the detection of fire/explosion in the crew compartment of the battle tank and a continuous type of linear thermal detector popularly known as fire-wire for the engine compartment. Halon-1301 has been employed as a fire extinguishing medium. The system is capable of detection and suppression of hydrocarbon fuel fire/explosion in the crew compartment within 200 milliseconds and in the engine compartment within 15 s thereby enhancing the chances of survivability of the crew and battle effectiveness of the tank.