n 1988-1989 two prototypes underwent automotive trials, which revealed major deficiencies in mobility, engine, and transmission.
[56]
The prototypes that underwent extensive mobility and armament trials, in 1996 and 1997 were found to perform below the acceptable standards and deficiencies were listed in the following areas:
[56]
- Accuracy of gun at battle ranges
- Mission reliability
- Ammunition lethality
- Containerization of ammunition bin
- Emergency traverse
- Fire control system unable to function in temperatures above 42 degrees Celsius (108 degrees Fahrenheit).[57]
The Arjun faced persistent problems of overheating and that "tank’s main subsystems, the fire control system (FCS), the suspension system, integrated gunner’s main sight, which includes a thermal imager and laser range-finder, which were rendered erratic and useless by the abnormally high peak internal temperature of beyond 55 °C in India. However, Major General H.M. Singh, a director in charge of trial and evaluation, said the user field trial report had certified the accuracy and consistency of the weapon system.
[58][59][60][61]
In August 2014, The apex Defence Acquisition Council (DAC) renewed a Rs 6,600 crore clearance for 118 Arjun Mark II tanks.
The United Progressive Alliance (UPA) government had already cleared 118 Arjun Mark IIs. That clearance had expired since the army has been evaluating the prototype tank for two years. The renewal allows the army to order the tanks from Heavy Vehicles Factory, Avadi, when trials are completed. Further support was extended to the Arjun tank project through the clearance of 40 self-propelled artillery guns, worth Rs 820 crore. This gun system, termed a "catapult", consists of a 130-millimetre gun mounted on an Arjun tank chassis, allowing it to keep up with tank columns and provide them fire support in battle.
[97