The government was reluctant to give up on the Arjun, as so many politicians had praised the project as a military and nationalistic success. But every time a prototype was put to the test, the results were disappointing. As has so often happened with other weapons projects, the Arjun is having problems with its electronics. In the last round of tests, it was the fire control system. But Arjun has also had problems with its engine, and that fact that its size and weight prevents it from being used with current tank transporters. The Defense Ministry could not bring itself to admit defeat, so all attempts to just cancel Arjun failed. Until now.
Six years ago, the situation became critical, because the army needed a new generation of tanks and the Arjun wasn't ready. So the army ordered 310 T-90 tanks from Russia, mainly to check them out. This was the beginning of the end for Arjun, that was supposed to be the successor to the Russian T-72, currently the first line Indian tank. The Defense Ministry still insisted that Arjun production would go forward. But the government engineers could not make Arjun work. There were also problems with using manufacturing technology, imported from Russia, to build components for Indian made T-72s, to build similar components for Arjun. About two thirds of the components in the Arjun and T-72 were interchangeable. But the technology transfer agreements with Russia only allowed India to manufacture these components for T-72s, not another tank design. The lawyers screwed up on this one, and Indian manufacturers were not able to design and build replacement parts that India could afford. The Arjun was going to cost more than imported T-90s.
Four years ago, desperate Ministry of Defense officials made plans to mount the turrets from the Arjuns on T-72 chassis, overcoming many of the construction problems. The Arjun chassis would then be used for a new Bhim self-propelled 155mm howitzers, with the South African Denel T-6 turret. The T-72 with the Arjun turret would be called Tank EX. The Denel turret proved to be too expensive, and too many components in the Arjun turret were still having problems, so this scheme was abandoned as well. At that point, the army began to refurbish some of its 1,700 T-72s, equipping 200 of them with additional armor (ERA), a new engine and upgraded electronics. The army began to look on the T-90 as its next generation tank, but it took four years for the Defense Ministry, and politicians, to admit that Arjun would not work.
Many of the problems with Arjun had to do with nothing more than government ineptitude. The Ministry of Defense was more interested in putting out press releases, about how India was becoming self-sufficient in tanks, than in attending to the technical details needed to make this happen. The Ministry of Defense crowd has done this sort of thing many times. Moreover, if it isn't incompetence screwing things up, then it's corruption. Cleaning up the Ministry of Defense, and all the politicians that get involved with it, is, so far, a problem without a solution.
India has decided to relegate its Indian designed and built tank, the Arjun, to training duties, and will not put these tanks into mass production. Thus ends a three decade effort to create an Indian designed and built tank. The 35 Arjuns already built are too large (heavy and wide) for existing tank transporters. The Arjun is also considered too unreliable for combat. But for training purposes, they are adequate, so it's not a complete waste.