Indian Army Begins First Arjun Mk-1 Overhaul with 26 Mk-1A Upgrades

The Indian Army has initiated the first full overhaul of its Arjun Mk-1 main battle tanks, beginning with two vehicles that will also receive 26 improvements derived from the newer Arjun Mk-1A. The pilot programme marks an important step towards extending the operational life and improving the combat capability of the Army’s 124-strong Arjun Mk-1 fleet.

The two tanks will be dismantled and rebuilt at the Heavy Vehicles Factory at Avadi near Chennai. The procedures, repair standards and assembly documentation developed during this initial programme are expected to form the template for the subsequent overhaul of additional Arjun Mk-1 tanks.

Six Major Mk-1A Improvements

Of the 26 modifications planned for each tank, six are described as major upgrades. These include a commander’s panoramic sight, Mk-II gunner’s main sight, automatic target tracker, improved muzzle-reference system, upgraded track and advanced running-gear system.

The remaining modifications include improvements such as a compact high-power auxiliary power unit, enhanced fire detection and suppression system, LED headlamps, improved dust sealing and heating elements for the tank’s periscopes. Together, the changes will bring important elements of the original Mk-1 closer to the technological standard of the newer Mk-1A.

The Mk-1A itself incorporates dozens of improvements over the original Arjun, including upgraded protection, mobility, sights and fire-control capabilities. The Ministry of Defence ordered 118 Arjun Mk-1A tanks for ₹7,523 crore in September 2021.

First Complete Overhaul of the Arjun Mk-1

The development is particularly significant because the Arjun Mk-1 has never previously undergone a complete tank-level overhaul. Although work has been carried out on engines and powerpacks, the new programme will involve stripping and rebuilding the hull, turret and major mechanical and electronic assemblies.

The Arjun Mk-1 began entering Army service in the mid-2000s. India produced 124 tanks for the Army, which equipped the 43 Armoured Regiment and 75 Armoured Regiment. The Heavy Vehicles Factory at Avadi has served as the production centre for the indigenous main battle tank.

During the overhaul, major assemblies will be sent to specialised facilities. The engine will be handled by Engine Factory Avadi, while other organisations will undertake work on the transmission, 120-mm main gun, gun-control system and associated components. Several replacement systems are also expected to be sourced from Indian manufacturers.

Pilot Programme Could Shape Fleet-Wide Modernisation

Once rebuilt, the two tanks are expected to undergo a sequence of structural, mobility and firing evaluations, including hull and turret tests, running trials and limited validation at the Pokhran field firing range.

The pilot programme is therefore more than routine maintenance. It will determine how India can systematically overhaul ageing Arjun Mk-1 tanks while simultaneously incorporating selected technologies developed for the Mk-1A.

The programme also represents an opportunity to increase the use of domestically produced replacement components as older imported systems become difficult to source.

For the Arjun programme, the first overhaul therefore marks an important transition: the original Mk-1 fleet is entering a new lifecycle phase in which deep refurbishment and selective Mk-1A modernisation can keep the tanks operationally relevant while India’s newer armoured platforms enter service.

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