New Kid On The Block


Arjun Mk2 MBT’s pre-production prototype to rollout by mid-2009


By Prasun K. Sengupta

Unfazed and undeterred by the quality-control problems that have beset the series-production phase of the Arjun Mk1 main battle tank (MBT) at the assembly line of the ministry of defence-owned Heavy Vehicles Factory in Avadi, the DRDO’s Avadi-based Combat Vehicles Research & Development Establishment has embarked upon the development of the third-generation Arjun Mk2 MBT, whose first pre-production prototype is due for rollout by mid-2009, as per present estimates. As per the Army HQ’s General Staff Qualitative Requirements (GSQR), this MBT — to be manned by a three-man crew complement will have a redesigned rear hull section and turret, an enhanced powerpack, a turret-mounted autoloader coupled to a redesigned turret bustle, an improved 120mm rifled-bore main gun controlled by a new hunter-killer digital fire-control system (DFCS), and a novel environment control system being co-developed with Israel’s Kinetics Ltd that will provide NBC air filtration/over-pressure generation, as well as cooling for the vectronics (all built by the MoD-owned Bharat Electronics Ltd) and crew compartment. The redesign of the Arjun Mk2’s hull and turret sections, and R&D work on the autoloader is being undertaken with the help of France’s Nexter Systems.

The main gun, which currently has a barrel length of 44 calibres, will be increased to 52 calibres by the DRDO’s Pune-based Armaments R&D Establishment. The gyro-stabilised gun will be insulated with a thermal sleeve and will incorporate a muzzle reference system, as well as an automatic compressed air fume extraction system instead of the Arjun Mk1’s existing fume extraction cylinder. The turret, to have a rotation time of nine seconds through 360 degrees, is being redesigned around the ammunition autoloader, which will hold 22 rounds of up to five types of ready-to-fire rounds and will permit a rate of fire of 12 shots per minute. Another 20 rounds and their modular charges will be housed within a pressurised turret bustle whose temperature will be cryogenically controlled. The main gun, to have a combat range of 5.5km when firing FSAPDS kinetic-energy rounds, will have maximum elevation/depression angles of +20 degrees and -9 degrees. The Arjun Mk2 will share with its predecessor the same imported all-electric power traverse system (supplied by Germany’s ESW Extel Systems Wedel), which comprises the automatic elevating and traversing drives with semi-automatic back-up, direct gun-laying with electrical instruments control and manual control. The DFCS will include an independent commander’s panoramic sight incorporating a medium-range uncooled thermal imager, and the Sagem Défense Sécurité-built IRIS thermal camera of the gunner’s sight that can ‘see’ at around 5.5km, recognise a target at 3.1km and identify targets at 2.5km. The gunner’s sight will incorporate an ‘auto tracker’ — an optronic system based on image processing that will simultaneously track up to six moving targets. As the gunner’s sight is fixed on a target, a picture analysis will take place. When the target moves, the 120mm gun and the gunner’s sight will get aligned with the target and will move automatically while keeping the target in focus. This is particularly good in cross-country terrain when the target is moving and the MBT might go through bumps or twists or turns for manoeuvring, but the ‘auto tracker’ will not lose sight of the target. Presently, the Arjun Mk1 uses a ‘director mode’ for track initiation. On the Arjun Mk2, the top mirror of the gunner’s sight will be independently stabilised, and a digital ballistics computer will evaluate the elevation of both the top mirror and the main gun, as well as the angle of the turret. There will be a continuous feeding of these parameters into the ballistics computer, which in turn will give electronic instructions to the all-electric gun-control system. Hence, the crosshairs of the gunner’s sight will be right in the middle of the target even in a cross-country environment. If, momentarily the gun is misaligned, the firing circuit will remain closed and the gunner will not be able to fire. The DFCS will receive all required meteorological data from IRDAM SA of Switzerland’s Model 2156B sensor that will measure wind speed, wind direction, air temperature and atmospheric pressure. All-terrain navigational accuracy will be provided by a fibre optic gyro-based autonomous land navigation system (ALNS) that can store more than 100 routes and 500 waypoints. The communications element of the Arjun Mk2’s vectronics suite will include a digital universal control harness duplex communications system for ensuring voice and data communications between the MBT commander, gunner and driver, and an AQ-6411 intercom system meant for inter-communications between crews of the host MBT and also with other MBT crews through the STARS V50WFF LVM-271 radio. Also using this radio will be a BEL-built battlespace management system (BMS), which will allow all friendly MBTs to share a common operating picture and give senior armoured corps commanders a comprehensive view of the battle space. It will also free up frontline MBT commanders from routine reporting tasks. The BMS will be capable of displaying relevant digital moving map data (in 2-D) and plotting of own position, will offer zooming, panning, fit-all, overlay and refresh modes, will plot the positions of friend or foe as well as mines, bunkers etc using different symbols, will generate path profiles, will send situation reports and receive operational order updates. The BMS will also be linked to the MBT’s on-board health and usage monitoring system (HUMS), an achievement that will significantly reduce the MBT’s operational logistics demands.