The 81 mm Carrier Mortar Tracked Vehicle (CMTV) was developed under the direction of the Indian Ordnance Factory (IOF) to meet the operational requirements of the Indian Army to provide indirect fire support for its mechanised infantry.

The Indian Ordnance Factory Medak has manufactured the Russian Kurgan Machine Construction Plant BMP-2 infantry combat vehicle (ICV) for many years under the local name of Sarath.

Since the first Sarath rolled off the production line as far back as 1987 it is estimated that well over 1,000 vehicles have been built. As far as it is known there have been no exports of the Sarath or its variants by India.

The first prototype of the 81 mm CMTV was completed in 1997 and following trials this was accepted for service by the Indian Army, with first production vehicles completed in 2000. So far more than 100 vehicles have been delivered according to the IOF.

The new 81 mm CMTV is based on the chassis of the Sarath ICV, which has had its two-person 30 mm turret removed and the hull modified for its new role.

The 81 mm mortar is mounted in the rear of the hull and fires through a two-part roof hatch that opens left and right.

The 81 mm mortar has a traverse of 24° left and right with elevation from +40 to +85°. A total of 108 × 81 mm mortar bombs and associated propelling charges are carried.

A mortar baseplate is carried externally, which allows the mortar to be dismounted and deployed away from the vehicle, if required by the tactical situation.

Mounted on the forward part of the hull is a 7.62 mm machine gun for local and air defence purposes and for this a total of 2,350 rounds of ammunition are carried.

As well as the small arms of the crew, an 84 mm Carl Gustaf anti-tank weapon is carried plus 12 rounds of ammunition. As it is used in high ambient temperatures 320 litres of drinking water are carried.

The 81 mm CMTV is operated by a crew of six, which includes the driver and commander, and has a combat weigh of 14.3 tonnes and a power-to-weight ratio of 21 hp/t.

It is fully amphibious and is propelled in the water by its tracks at a maximum speed of 7 km/h. Before entering the water a trim vane is erected at the front of the hull and the electrically-operated bilge pumps are switched on.

The 81 mm CMTV is the latest in a long line of Sarath variants developed by the IOF for the Indian Army with earlier models including an ambulance, engineer reconnaissance and armoured dozer.

Stretched and modified versions of the Sarath chassis have been developed for a number of missile applications including the Nag anti-tank guided weapon and the Akash and Trishul surface-to-air missile systems. As far as it is known, by late 2007 none of these have yet entered quantity production.