India is upgrading 600 of its Russian T-90 tanks with new electronics (navigation systems, thermal sights and fire control computers) and air conditioning at a cost of about $42,000 per tank. The main reason for air conditioning in the tanks is not the crew, but the electronics. Russia was asked to develop and install air conditioning but were unable to create a system that could handle the Indian climate. That failure caused a lot of damage to the Russian and foreign made electronics in the Indian T-90s, thus the need for these changes.
One of the most obvious reasons for this upgrade was the heat related problems. Despite years of effort India was unable to get the thermal imaging systems to operate reliably on its T-90 tanks. Most of the thermal imagers on the T-90s were down at any one time. The problem was eventually found to be heat, and the 40 degree (Celsius/104 Fahrenheit) heat is unavoidable because it's a desert area where Indian T-90s have to be stationed. The Indians paid $2.6 million for each tank (half the price of the U.S. M-1). Some 20 percent of the cost was for the thermal sight, similar to the one that makes the U.S. M-1 tank so effective on the battlefield. Unfortunately, tests of the T-90 revealed that the thermal sight system could not handle the heat of Indian summers once the air conditioning failed. Much of the border between India and Pakistan is desert, and most of India's armored units are stationed there. The problem is that while the T-90 had Russian developed air conditioning (something new in Russian tanks), it cannot handle the 100+ degree heat in tropical India. The Russians were unable to develop a suitable upgrade because there was no room inside the tank to install a more powerful, but larger, cooling system. The American M-1 air conditioning has been able to handle extreme heat, so the Indians knew it could be done and eventually found a supplier who could build a system that worked and fit into the space available.
The T-90 went into low level production in 1993, but was too expensive for the Russian army to buy more than a few of them. India eventually became the biggest user. The T-90 is based on the T-72, but has composite armor (plus reactive armor) and better electronics. The 50 ton tank uses a 125mm smooth bore gun, and can also fire the 9M119M Refleks-M missile (to 4,000 meters) at ground or air (helicopter) targets. The tank carries 43 tank shells or missiles, 22 of them in the autoloader carousel. India agreed to buy 310 T-90s initially and is to have over 1,600 of them by the end of the decade, most of them assembled in India using Russian made parts.
One big reason India bought the T-90 is the 9M119 (AT-11) anti-tank missile, which weighs 23.6 kg (52 pounds), has a range of 100-4,000 meters and uses semi-automatic laser beam guidance system (the gunner keeps his sight on the target and the missile homes in on that.) Maximum time of flight is about 12 seconds. While the missile has a tandem warhead, making it useful against tanks with reactive armor, it can also be used against helicopters. The missile warhead can penetrate about 700mm of armor. The guidance system is quite accurate, hitting the target 80 percent of the time at maximum range in tests. The guidance system is also easy to use, making less well trained crews more effective. However, India insisted on building the missiles under license. This has created problems, as the Indian manufacturer has not been able to achieve sufficient quality control levels.
India deployed its first T-90 regiment (45 tanks) in May, 2002. The first T-90s were delivered to India in late November 2001. When they work, the T-90s are more than a match for anything the Pakistanis or Chinese have.