Arjun Development Program

The Main Battle Tank Project sanctioned in May 1974 envisaged bulk production by April 1984. However this time frame was not adhered to and was revised from time to time and bulk production was to commence from 1990 onwards but even the revised time frame could not be adhered to. As per time frame fixed in May 1974, four mild steel prototypes were to be offered for trials by April 1980 and eight armoured prototypes by April 1982. Trickle production was due to commence by April 1983 and bulk production by April 1984. This schedule was revised from time to time.

One of the early Arjun prototypes was unveiled in April 1985, with a number of prototypes undergoing technical testing while desert trials were scheduled for that summer. At the time, it was reported to have a 120mm smooth-bore main gun and would use a 1400-hp MTU-based diesel until an indigenous one was ready. Weight would be about 50 tons, and the tank would cost about $1.6 million (U.S.). Development costs rose about 500 percent throughout the '80s, and through a development process plagued with delays, the end product visually resembles the German Leopard II, however, unlike the German vehicle, its future remains in doubt.

A total of 12 MK-I prototypes based on imported propulsion unit, seven MK-II prototypes with indigenous propulsion were to be delivered by June 1987 and June 1990 respectively; 23 MK-I, PPS tanks by December 1988 and bulk production was to commence from 1990 onwards. As against this, 12 MK-I prototypes with imported propulsion were produced by February 1989 and 15 MK-I PPS tanks upto December 1996. At thatt ime the MK-II type prototype were not expected to be ready in the near future on account of the delays in the development of the indigenous engine.

As the indigenous efforts to develop a suitable engine and transmission system for the MBT were beset with problems, 42 power packs with transmission units were imported between November 1983 and 1988 from Germany for use on the prototypes and PPS tanks. However, as the imported transmission system was designed to cater up to 60 tonne load as against the all-up weight of 61.5 tonne for the MBT, a mismatch had arisen between engine and transmission which had resulted in bulging of side walls of the hull.

The automotive trials of two prototypes carried out by Army during 1988-89 revealed major deficiencies. The Army, therefore, on 26 July 1989 wanted these deficiencies to be sorted out before commencement of production of pre-production series (PPS). However, on 31 July 1989 Ministry decided to place orders for the production of PPS tanks. Two fully integrated prototypes were given to the Army for full fledged evaluation only in March 1990 after the commencement of production of PPS tanks. The evaluation trials of the prototypes also revealed major deficiencies. Subsequent trials were conducted on PPS tanks.

The project finally was closed in March 1995 with a total expenditure of Rs 305.60 crore with delivery of 12 nos of prototypes and 15 nos of Pre-Production Series of Arjun tanks. These tanks underwent extensive field evaluation with the Army wherein approximately 70,000 km of mobility trials and 7000 rounds of main armament were fired. The Summer trials carried out in April 1997 on PPS-15, reference tank for bulk production indicated that though there was improvement from the previous years, it was still below the acceptable standards. The major deficiencies pointed out in the summer trials of 1996 i.e. accuracy of gun at battle ranges, mission reliability, lethality of ammunition, containerisation of ammunition bin, emergency traverse etc. continue to persist and were yet to be solved.

Till July 1997, 15 pre-production series tanks which were subjected to extensive user and troop trials failed to meet fully even the bottom line parameters of the user. The Army accordingly indicated in July 1997 that in its present form, the overall reliability of MBT Arjun was far from satisfactory. The Army further indicated that periodic failures of equipment and subsystems tend to reduce the confidence level of troops. The Army also observed that the aspect of armour protection had not been tried out.Army recommended in June 1997 that Limited Series Production should commence only after all the observations and shortcomings noticed were rectified and shown to them.

As of mid-1997 the list of faults after 20 years of development was not encouraging. In addition to numerous technical modifications to its fire and gun control systems, the fire control system in particular has been found unable to perform in temperatures above 42 degrees Celsius (108° F). The DRDO has been considering scrapping the current Arjun fire control system in favor of whatever is accepted for the T-72M1 upgrade program. Defects noticed during the user trials of the Arjun Mk.1 MBT, including over-heating of the engine in Rajasthan desert areas, had supposedly been "by and large overcome" while other complaints were being addressed.

MBT Arjun would require increased maintenance time and efforts, according to the Army. The Army accordingly expressed grave concern on the reliability and maintainability of MBT and pointed out that while the world over the trend was to reduce the maintenance time, it had increased with MBT Arjun. According to DRDO, the views expressed by the Army are only a subjective opinion and the analysis of data shows an upward trend in mean time between failures (MTBF) over the years. DRDO have pointed out that trials carried out clearly brought out the efficiency/improvements effected in weapon system and in the automotive area ability to cover the required range in the stipulated time was also proved. They further contended that there is no overheating of the engine in desert conditions. Summer trials of 1997 indicated that the performance was below the acceptable standards.

The equipment was approved by Army and an indent of 124 nos of MBT Arjun was placed on Heavy Vehicle Factory/Ordnance Factory Board (OFB) in March 2000. Army carried out the Accelerated Usage Cum Reliability Trials (AUCRT) in 5 phases on two tanks from Nov 2007 to Aug 2008 covering more than 8000 km and 800 rounds of firing in each tank. AUCRT is required for assessing the spares requirement for the entire life of the tank besides evaluation of reliability of tank. Each phase consists of 1000kms run and 100EFC (Approx. 160 rounds of APFSDS and HESH – Primary and secondary rounds) over a temperature range of -5 to 500C. One of the main issues during AUCRT trials was the failure of the bearings of Transmission of M/s RENK, Germany, due to rise in lub oil temperature. However, this was immediately solved by modifying the software during AUCRT itself and the efficacy of the software was proved for more than 4000kms. However a comprehensive solution of modifying the bearing assembly by providing a special coating was carried out to take care of the temperature problem and the retrofitment of bearing assembly being carried out in all the tanks.

In late August 2008, the army completed nearly a year of Accelerated User Cum Reliability Trials (AUCRT) and somewhat unprecedented, extended trials in the desert of Rajasthan. These trials tested the three characteristics of any battle tank - firepower, mobility and protection. Following defects were noticed during the ongoing Accelerated User Cum Reliability Trials by Army:-

• Failure of power packs
• Low accuracy and consistency
• Failure of Hydropneumatic Suspension Units
• Shearing of Top Rollers
• Chipping of Gun Barrels

The rectification of defects and performance of tanks were being closely monitored. The outcome of AUCRT trials raised the confidence levels of the users over the reliability and endurance of MBT Arjun and they confirmed that the overall performance of the MBT Arjun during the stringent AUCRT trials was satisfactory and cleared the production tanks with minor modifications suggested during AUCRT, for induction. Both CVRDE and HVF along with DGQA agencies worked out methodologies to introduce all AUCRT modifications within shortest time frame and the next batch of 17 tanks were handed over to Army by 3rd March 2009.

As suggested by Army after AUCRT trials, Arjun tanks were subjected to rigorous trials and assessment by a third party audit (an internationally reputed tank manufacturer). After the extensive evaluation, the reputed tank manufacturer confirmed that the MBT Arjun is an excellent tank with very good mobility and fire power characteristics suitable for Indian desert. They also added inputs such as quality auditing, production procedures and refined calibration procedures for further enhancing the performance of MBT Arjun. DRDO, will be incorporating all these inputs in the next regiment of 62 tanks for handing over to Army before Mar 2010 as desired by the Army.