Orders Placed For Arjun Mk1A MBT’s Vectronics Suite

Elbit Systems Electro-optics Elop Ltd (ELOP) on March 20 was awarded an approximately US$80 million contract for supplying major elements of the vectronics suite for the 118 Arjun Mk1A main battle tanks (MBT) that were ordered for the Indian Army last January. ELOP will complete all deliveries by 2015. Each vectronics suite will include ELOP-supplied Advanced laser warning & countermeasures system (ALWACS) and the commander’s open-architecture panoramic sight (COAPS). The ALWACS will include four E-LWS sensors that can detect, categorise and pinpoint laser sources, including rangefinders, designators, beam-riders, and infra-red illuminators. E-LWS also enables direction indication for all threats, as well as audio and visual warnings. It is immune to reflection, gunfire, lightning, fire and self-electro-optical operations. The other two components of ALWACS are an IR jammer, and two 8-launcher aerosol smoke screening systems. 

The COAPS is a dual axis stabilised line-of-sight, remote-operated, periscopic system for independent target acquisition, battlefield surveillance and main gun firing in a ‘hunter-killer’ auto-track mode. The COAPS will use a SAGEM-built Matis-STD thermal imager (to be supplied to ELOP as customer-furnished equipment) that operates in the 3-5 micron bandwidth, while the gunner’s sight will employ a THALES-built Catherine-FC thermal imager (to be supplied to ELOP as customer-furnished equipment), operating in the 8-12 micron bandwidth. The COAPS will also house an integrated Laser Target Tracker (LTT) for providing fire-control solutions for the CLGM laser-guided anti-helicopter missile.

All in all, the Arjun Mk1A MBT, having a per-unit cost of Rs34 crores, will feature 93 improvements, including 19 major modifications, which will be introduced in two phases. In Phase-1, 45 Arjun Mk1As will roll out with 56 upgrades, including the ALWAC S, COAPS, and CLGM-firing capability. In Phase-2, the remaining 73 Arjun Mk1As, with all the 93 improvements, will be delivered.

Structurally, the major enhancement on the MBT will be the fitment of High Energy Materials Research Laboratory-developed explosive reactive armour (ERA) plates weighing a total of 1.5-tonnes on the glacis plate, as well as the front of the turret and the sides protecting the driver’s compartment; fitment of a 1.5-tonne track-width mine plough sourced from US-based Pearson Engineering (represented in India by BEML); incorporation of a new 8kW auxiliary power unit (APU) developed by Indesys Equipments Pvt Ltd; redesigned and bigger road wheels built by Sundaram Industries; and Germany-based Diehl Remscheid’s DST 570V tracks, whose basic components include the track links, sprocket wheels, guide wheels, running rollers, support rollers, running pads, traction aids, connectors, bolts, mono block-body with integral centre guide, rubberised track pads, and grouser.

To be mounted on the turret will be a yet-to-be-selected remote controlled weapons system containing a 12.7mm heavy machine gun. Finally, a mobile camouflage system has been developed and integrated into the Arjun Mk1A in collaboration with Sweden’s Barracuda Camouflage Ltd to reduce the MBT’s signature against all known sensors and smart munitions.

As a result of all these add-ons, the Arjun Mk1A’s fully loaded weight will be 67 tonnes. To cater to this weight increase, the MBT’s Kirloskar-built hydropneumatic suspension systems has been re-designed to cater for weights of up to 70 tonnes. Track-shedding problems have been resolved by selecting the DST 570V tracks that will have an increased horn length (19mm). The MTU 838 Ka-501 diesel engine and RENK’s RK-304S gearbox (making up the powerpack) has been retained for the Arjun Mk1A. On the Arjun Mk1, the final drive had catered to a top speed of 72kph. For the Arjun Mk1A, the final drive has been enhanced by increasing the reduction ratio from 4.4 to 5.3, while the top speed now stands at 58.5kph. In addition, the torque and the force available at the contact between the track and the surface has been increased which to cater for the MBT’s increased weight. However, despite the increased weight, the Arjun Mk1A’s acceleration is better than the Arjun Mk1, while fuel efficiency and the power-to-weight ratio of 23.9hp/tonne remain the same. The DST 570V’s increased track-width will ensure that the ground pressure (0.84kgf/cm2) remains the same in spite of the MBT’s increased weight.

What is significantly missing on the Arjun Mk1A, however, is a slat-armour package to protect the Arjun Mk1A’s rear section against rocket-propelled (RPG) attacks. By acting as a rigid barrier, slat-armour, made of aluminium alloy, causes the RPG’s shaped-charge warhead (which uses a shaped-explosion rather than kinetic energy) to explode at a relatively safe distance.

To be selected in the near future is a remotely-controlled weapons station, for which Israel Military Industries’ (IMI) WAVE-300 was chosen, but had to be subsequently dropped due to IMI’s blacklisting by the MoD last year. Shortlisted contenders for supplying the RCWS include Elbit Systems’ ORCWS, RAFAEL’s Samson-30 and SAAB’s Trackfire.

The first Arjun Mk1A will roll off the MoD-owned and Avadi-based Heavy Vehicles Factory (HVF) in July 2015, and enter service in early 2016. HVF will annually produce 30 Arjun Mk1As, meaning the last such MBT will be delivered by 2019.

Being negotiated now is the production of 40 BLT-Arjun armoured recovery vehicles, along with other specialised combat engineering vehicles like 20 CMF-Arjuns and 20 full-width mine-ploughs mounted on the hull of an Arjun (this being a turret vehicle). BLT-Arjun will be cantilevered over chasms or across rivers to cover a distance of 26 metres with a width of 4 metres. The BLT-Arjun will carry two halves of an all-composite (using multi-layered multi-functional fibre-reinforced polymer) 26 metre-long MLC-70 single-span bridge. At a wet or dry gap, the launcher will slide the two parts and dock them to each other in such a way that the far end of the second half touches the other bank. The BLT-Arjun will then cross the bridge, turn around, retrieve the bridge after undocking its two halves, fold it and will be ready to move with the armoured column.

The counter-mine flail, under development since 2005, has been designed to clear safe 4.5-metre wide lane for the passage of armoured vehicles and personnel by detonating anti-tank/anti-personnel mines buried up to a depth of at least 30cm with the help of hydraulically-operated hammers. The CMF-Arjun will have a series of 10kg hammers that will pulverise mines by beating them at 400 revolutions a minute. Equipped with GPS and periscope, the CMF-Arjun will also have a marking system, which, with the help of LED poles, will mark safe lanes in the battle zone after having disabled the mines laid by the enemy. Ideally, the turretless CMF-Arjun will also house a 7.62mm PKT machine gun, 12.7mm anti-aircraft gun and smoke grenade dispenser.

Finally, a mobile camouflage system has been developed and integrated into the Arjun Mk1A in collaboration with Sweden’s Barracuda Camouflage Ltd to reduce the vehicle’s signature against all known sensors and smart munitions.

Also being evaluated now is a proposal for upgrading up to 400 BMP-2K infantry combat vehicles (ICV) by equipping them with a new-design turret housing up to four anti-armour guided-missiles (like the CLGM), a 30mm cannon, a remote-controlled weapon station housing a 30mm automatic grenade launcher, a COAPS, and a gunner’s day/night sight making use of ELOP’s TISAS system.

Looking To The Future

From the above, it is evident that the Arjun Mk1A MBT was developed in a hurry and therefore certain avoidable compromises were made. For instance, It is obvious that instead of accommodating a 1.5-tonne ERA package for very limited protection-levels, it would have been far better if an active protection system (APS) weighing no more than 850kg was adopted, which would at least have given the MBT 360-degree protection. To this end, either RAFAEL Advanced Defence Systems’ Trophy HV (ASPRO-A) system, using 8ELTA System’s EL/M 2133 WindGuard flat-panel radar (four units) and RAFAEL’s multiple explosive-formed penetrators (MEFP), or Saab’s LEDS-150 systems (using Mongoose KE rounds and already selected for the Indian Army’s first 310 imported T-90S MBTs to be subjected to a mid-life upgrade) ought to have been evaluated for a final selection process. Similarly, a slat-armour package to protect the Arjun Mk1A’s rear section (housing the powerpack compartment plus the twin external fuel tanks) ought to have been adopted.

Other avoidable options were the installation of COAPS and the acquisition of CLGM-firing capability. Instead, the Arjun Mk1A could easily have been equipped IRDE-developed and BEL-built commander’s panoramic sight, which is now undergoing user-trials and was originally developed for the T-90S. The IRDE-developed and BEL-built commander’s panoramic sight (which houses a SAGEM-built MATIS-STD thermal imager operating in the 3-5 micron bandwidth), would have resulted in enhanced static visibility levels for both the gunner and commander.

Arjun Mk2 MBT
As I had stated in mid-2011, for all intents and purposes, the Arjun Mk2 MBT—currently under development since mid-2007—will be more expensive and have a higher imported content than its predecessor, the Arjun Mk1. But in terms of mobility, protection and firepower, the Mk2 variant will come closest to what Indian Army HQ wants: an MBT with highly enhanced crew protection and maximum survivability in high-intensity, fire-saturated combat environments. To achieve this, the CVRDE has roped in Cummins India and Elbit Systems, with the former being responsible for improving mobility and fuel consumption, and the latter for redesigning and modifying the MBT’s digital vectronics suite, gun-control system, survivability systems and air-conditioning hardware. 

Work on developing the Arjun Mk2 began in the second half of 2007 soon after joint R & D contracts were inked between the CVRDE, Cummins India and Elbit Systems. On October 31 that year, the CVRDE floated domestic and global expressions of interest for the co-development of a 1,500hp compact high specific power output diesel engine incorporating a state-of-the-art direct fuel injection system, digital electronic controls, turbo-charging, charge air cooling, safety controls and a pressurised multi-stage air-cleaning system; and for a hydro-kinetic automatic transmission with four forward and two reverse gears. US-based Cummins, offering a customised QSK-38 liquid-cooled, direct-injection engine coupled to SESM of France’s ESM-500 automatic transmission. In late 2009, a combination of the QSK-38/ESM-500 powerpack was selected as the winner, following which Cummins India began customising this powerpack design. The ESM-500, with five forward and two reverse gears, contains a planetary gearbox with shifting, steering and braking systems. It is also equipped with a hydrodynamic steering system, which allows different turning radii depending on engine speed and selected gear. The braking system contains of two stages. As a parking brake and for a speed of up to 35kph air-cooled disk brakes are used. At higher speeds a retarder is used. In addition, the transmission is equipped with a power takeoff for the cooling fans of the powerpack. Also, a hydrokinetic retarder can slow the MBT down at a decelleration rate of 7 metres/square second (0.7g), which can be very useful at the last moment before it could be hit. 

Supplementing this powerpack will be an 8kW APU, which will provide power when the MBT is on ‘silent watch’ for battery recharging and night observation, with full systems operating while the main engine is shut down.

For ensuring MBT survivability, the Defence Metallurgical Research Laboratory (DMRL)e—located in Kanchanbagh, Hyderabad—has developed a Mk2 variant of its Kanchan modular armour, which was made by sandwiching composite panels (ceramic, alumina, fibre-glass and nickel-alloy) between rolled homogenous armour (RHA) plates to defeat APFDS or HEAT rounds. Also developed for the Arjun Mk2 is an appliqué co-cured composites integral armour (CIA) package (for the frontal turret and hull-sides flanking the driver’s compartment), which comprises ceramic tiles and rubber sandwiched between two FRP composites layers. While the outer FRP composite layer acts as a cover and provides confinement, the ceramic layer provides primary protection against ballistic impact, and the inner FRP composite layer acts as the structural part as well as secondary energy absorbing mechanism. The rubber layer isolates stiff and brittle ceramic tiles from structural member.

The Arjun Mk2 will do away with the existing electro-hydraulic turret control system (which is susceptible to impact damage and can cause a fire hazard) and will instead use a totally electronic modular electric gun and turret drive stabilisation (EGTDS) system supplied by Elbit Systems. The EGTDS uses azimuth/elevation motor drives with extremely rapid response time, low-voltage power, stabilised modes of operation, and manual back-up drives in both elevation and traverse. A digital servo-gun/turret drive stabilisation system will be employed for isolating the gun platform from the effects of vehicle pitch, roll, yaw and jolt as the MBT manouevres and fires at the same time. Additionally, the gun-laying drives are electric powered for high-precision first-round hit probability while on the move. A motor drive-control unit will transform the power supply into two 3-phase systems. These will supply and control the servo motors for alignment, stabilisation and slave mode of the turret/wea­pon according to the input signals of the sensors, control handles and active sight. The EGTDS will ensure smooth target-tracking at all speeds for very heavy turrets and guns and at extreme turret gun positions, while low power consumption will lead to low infra-red signature as well as low-noise levels.

The Arjun Mk2’s turret will also house an integrated battle management system (BMS) designed by Elbit Systems (and licence-built by Bharat Electronics Ltd), which, like on the Arjun Mk1A, will provide rapid communications networking between the tactical tank commander and his subordinate units. It will enable the tank commander to plan missions, navigate, and continuously update situational awareness. The system will also record data for operational debriefing by using a digital data recorder, which will record and restore sight images and observation data collected during missions. This data can be shared with other elements, using the same network with the BMS, to report enemy targets.

The Arjun Mk2’s turret-mounted autoloader (also being developed indigenously) will be able to load the 120mm rifled-bore main gun from a fully automated, fire-proof magazine, which will accommodate up to 10 ready rounds and deliver up to four types of ammunition types to the loader. In addition to APFSDS and hyperbaric rounds, the Arjun Mk2 will make use of indigenously developed APAM munitions designed to neutralise—especially in urban built-up terrain—tank-killer squads lurking with lethal anti-tank weapons. The APAM will use the proven concept of anti-personnel munitions based on controlled fragmentation. It will deploy sub-munition shrapnel at defined intervals, covering a wide lethal area against soft targets. Each fragment is shaped to have enough kinetic energy to penetrate conventional body armour, or other materials.

For improving crew comfort, the Arjun Mk2 will incorporate an Elbit Systems-supplied individual crew and equipment cooling system (ICECS), while will provide cooled and dried air from a special air conditioner to air-cooled overalls or vests. The air will naturally cool the upper torso of each crewman. Also being acquired from Elbit through a transfer-of-technology agreement for the MBT crew are regular/fire-resistant air-cooled overalls, NBC protected air-cooled overalls, and air-cooled compact vests.

As per Indian Army HQ’s present plans, by late 2015, it plans to place firm orders for 500 Arjun Mk2s, plus 80 BLT-Arjun Mk2s. At the same time, in my personal view, the hulls of at least 800 existing T-72M1982s should each be retrofitted with a Chelyabinsk Tractor Plant-built 1,200hp V-92S2 diesel engine (Ukraine has already offered its 1,200hp 6TD-2 engine), while an 8kW auxiliary power unit will provide back-up electric power when the engine is idling. Concurrently, these re-engined T-72M1982s should be retrofitted with the turret of the Arjun Mk2 (i.e. a re-engineered TANK-EX) so that the final product does not weigh more than 49 tonnes and has a power-to-weight ratio of 21hp/tonne and ground pressure of 0.94kgf/cm2.

Arjun Mk3 FMBT

Both the CVRDE and Indian Army HQ know only too well that the latter’s projected future MBT (FMBT)—contrary to weighing less than 50 tonnes as earlier envisaged—will ultimately weigh close to 70 tonnes even without the TWMP add-on. That being the case, the best option then is to authorise Cummins India to develop a 1,800hp version of the QSK-38 diesel engine by 2017, while the CVRDE concentrates on developing an indigenous automatic transmission. Ukraine, incidentally, has already offered its 1,800hp 6TD-5 diesel engine for the FMBT. Other essential design and performance criteria of the FMBT ought to be as follows:

The Arjun Mk3 MBT, like the Arjun Mk2, should have a three-man crew complement.

Its powerpack should include either an overdrive mode for facilitating acceleration from zero to full power in 2.8 seconds.

Its digitised vectronics suite—comprising the hunter-killer fire-control system, radar/laser warning system, CIFF transponder, APS, BMS, software-defined radio communications suite, health and usage monitoring system incorporating on-board diagnostics and maintenance log-book modes, multi-spectral decoy/camouflage generation system, APS, and the all-electric turret traverse/stabilisation system—should be integrated with a MIL-STD-1553B digital databus. 

The principal armament of the FMBT should be a 55-calibre 120mm smoothbore cannon firing APAM and APFSDS rounds.