the arjun mk2 will be a 60+ton tank and is most likely going to feature wedge shaped armour on the frontal portion like the leopard2a6. i found a very old article regarding the arjun mk2 from the net.it probably appeared first on force magazine though i am not sure.
arjun Mk2 MBT's pre-production prototype to rollout by mid-2009
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 [Defence Research and Development Organisation] Avadi-based Combat Vehicles Research & Development Establishment [CVRDE] 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 [nuclear biological chemical] air filtration/over-pressure generation, as well as cooling for the vectronics (all built by the MoD[Ministry of Defence]-owned Bharat Electronics Ltd [BEL]) and crew compartment. The redesign of the Arjun Mk2's hull and turret sections, and R&D [research and development] 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.
Another novelty to be introduced into the Arjun Mk2's hull and turret with optimised thickness will be Non-Explosive and Non-Energetic Reactive Armour (NERA) panels without explosive liners. NERA comprises two lightweight metal plates (made of tungsten alloy and active metal-brazing titanium/ceramic alloy) sandwiching an inert liner like rubber. When struck by a shaped-charge's kinetic-energy metal jet, some of the impact energy is dissipated into the inert liner layer, and the resulting high-pressure causes a localised bending or bulging of the metal plates in the area of the impact. As the plates bulge, the point of jet impact shifts with the plate bulging, thereby increasing the effective thickness of the armour. This is almost the same mechanism as the second mechanism that current-generation explosive reactive armour (ERA) tiles use, but NERA uses energy from the shaped-charge jet rather than an explosive. Since the inner liner is not explosive itself, the bulging is less energetic than that on ERA. In addition, when compared to ERA tiles, NERA is much lighter and completely safe to handle (and therefore safer for close-proximity friendly dismounted infantry), and can be packaged in multiple spaced-out layers if necessary. The frontal turret section will feature a sloped and modular armour package similar to that found on the German Leopard 2A6 HEL and Chinese ZTZ-99G MBTs.
The Arjun Mk2, unlike its predecessor, will have an indigenously-built 12-cylinder, air-cooled variable compressor ratio diesel engine rated at 1,500hp. The gearbox and transmission system will, however, be imported from RENK of Germany. The engine, to be developed over a 60-month period at a cost of Rs 600 million [$14 million], will incorporate high-pressure ratio turbochargers and classical high-pressure fuel injection system with all-digital electronic controls for achieving higher thermal efficiencies. To achieve compactness, technologies like flywheel-cum-starter generator and pressurised air filtration systems will be adopted. The CVRDE on 21 October 2006 floated domestic and global expressions of interest for the co-development of what it calls the compact high-speci fic power output diesel engine. While the CVRDE is leading the engine's overall R&D effort with technical help from Austria's AVL List GmbH, a consortium of public sector and private sector companies from India and abroad has been formed for developing the engine's various components, such as the piston assembly, turbocharger, digital fuel injection system, cylinder heads, cylinder blocks, crank case, cylinder liners, connecting rods and crank-shaft forgings, oil pumps, shell bearings, water pump, flywheel starter-cum-generator, accessory gear drive, air filtration system, compact plate and fin heat exchangers, plate heat exchangers, and the cooling fan. Companies involved in developing all these include UK-based Ricardo, Goetze India Ltd, the UK's Borg Warner Automotive Turbo Systems, Germany's Robert Bosch, MICO India Pvt Ltd, Praveen Castings Pvt Ltd, HAL's [Hindustan Aeronautics Ltd.] Foundry & Forge Division, SAN Engineering Ltd, Dynamatic Technologies Ltd, Magtorg Pvt Ltd, Apollo Heat Exchangers Pvt Ltd, Voras Exclusive Tools Pvt Ltd, Poona Shims Pvt Ltd, Pall India Pvt Ltd, Pearlite Liners Pvt Ltd, India Pistons Ltd, Bharat Forge Ltd, Rane Engine Valves Ltd, Bimetal Bearings Pvt Ltd, and Germany's MIBA Bearings. Development of the improved powerpack is imperative for meeting the Arjun Mk2's mobility parameters (including a power-to-weight ratio is 24.1hp/tone), especially since the MBT's all-up combat weight of 58.5 tonnes will go up to 61.5 tonnes once it is fitted with a 3-tonne engineering mine-plough. A HAL-built 4.5kW auxiliary power unit will be employed for silent idling and battery charging.
For maintaining a credible and nominal ground pressure is only 0.84kg/square cm, the Arjun Mk2 will make use of Diehl Remscheid's Model 570V double-pin steel tracks with detachable rubber pads, all to be licence-built by Larsen & Toubro. The tracks will be made of individual steel castings each having two bores for the insertion of rubberised pins. It will have an integral piece incorporating guide-horns and will have a provision for the insertion of detachable rubber-pads. The end-connectors will be induction-hardened in the area which comes in contact with the sprocket teeth to prevent wear.
The sprockets and rubberised road wheels will be built by a consortium of companies comprising MRF Ltd, Madras Elastomer Ltd, Dunlop India Ltd and Sundaram Industries Ltd. The hydropneumatic suspensions, co-developed by Bharat Earth Movers Ltd and Kirloskar, will be externally mounted and provide vehicle springing and damping. It will consist of one bogey wheel-pair for each suspension station. Gaseous medium in the hydropneumatic suspensions will be used for all-terrain manoeuvrability for exploiting the power available. Casings and hubs of the suspensions will be sealed for preventing dust ingression and water seepage during shallow/medium fording operations in marshy areas.
If, as per current schedules, the two Arjun Mk2 pre-production prototypes successfully complete user-assisted mobility and firepower trials by early 2011, a series-production run of 400 such MBTs is envisaged, along with 36 MLC-70 bridle-layer tanks (featuring twin slide-launch assault bridges of single-span tread way type construction and having a length of 26 metres) and a similar number of armoured recovery vehicles.
