Delays and problems in its development from the 1990s to the 2000s prompted the Indian Army to order vast numbers of T-90S tanks from Russia to meet requirements that the Arjun had been expected to fulfill.
The Arjun features a 120 mm main rifled gun with indigenously developed APFSDS ammunition, one 7.62 mm coaxial machine gun, and a 12.7 mm machine gun. It is powered by a single MTU multi-fuel diesel engine rated at 1,400 hp, and can achieve a maximum speed of 70 km/h (43 mph) and a cross-country speed of 40 km/h (25 mph). It has a four-man crew: commander, gunner, loader and driver. Automatic fire detection and suppression, and NBC protection systems are included. All-round anti-tank warhead protection by the newly developed Kanchan armour is claimed to be much higher than available in comparable third generation tanks.
In March 2010, the Arjun was pitted against the T-90 in comparative trials and performed well. Subsequently the Army placed an order for an additional 124 tanks on May 17, 2010.
The Arjun entered service with the Indian Army on 12 March 2011. The tanks were first inducted into the 75th Armoured Regiment in Jaisalmer, replacing T-55 tanks.
