VESSEL REVIEW | INS Nistar – Indian Navy's new dive support ship designed for submarine rescue missions

The Indian Navy recently took delivery of a new dive support vessel (DSV) designed and built locally by Hindustan Shipyard (HSL) in Visakhapatnam.

The future INS Nistar (निस्तार), named after the Sanskrit for “rescue,” is the first in a planned class of two long-endurance DSVs that will be used primarily for the rescue of crews of distressed submarines (the name Nistar had also been used for a submarine rescue vessel that the Indian Navy acquired in 1969 and operated from 1971 to 1989).

The DSV's secondary duties will include patrols, general search and rescue, salvage, underwater inspections, and non-combatant evacuation operations.

The vessel has a length of 118.4 metres (388.5 feet), a beam of 22.8 metres (74.8 feet), a displacement of 9,350 tonnes, and two diesel engines that deliver a cruising speed of 14 knots and an endurance of 60 days.

Space is available for a deployable submersible deep sea rescue vehicle and remotely operated vehicles used for divers’ monitoring and salvage. A flight deck capable of accommodating a 15-tonne helicopter is installed forward of the superstructure.

Full rescue capability under a broad range of depths and conditions

The DSV is equipped for conducting deep sea saturation diving to depths of as much as 300 metres (1,000 feet). The vessel also has a side diving stage for undertaking diving operations up to 75 metres (250 feet). A 15-tonne crane is fitted for retrieving underwater debris.

Diving operations are supported by a six-person decompression chamber, a diving bell, a moonpool, and a self-propelled hyperbaric lifeboat.

Extensive diver treatment facilities

The other onboard facilities include an operating theatre, an ICU, and a hospital with eight beds. The electronics meanwhile include a DP2 system, a radar, and a side-scan sonar, and an electro-optical/infrared fire control system.

The DSV is also armed with two AK-630 30mm point defence autocannon for self-protection against hostile manned and unmanned aircraft and guided missiles.

Construction of the future Nistar and sister vessel INS Nipun was undertaken by HSL in compliance with Indian Register of Shipping class rules. Construction of each of Nistar-class DSV entailed the use of approximately 75 per cent local content in line with the Indian Government’s “make in India” initiative.