VESSEL REVIEW | INS Arnala – Indian Navy's new submarine-hunting corvette designed for shallow waters

The Indian Navy recently commissioned a new corvette designed primarily for anti-submarine warfare (ASW).

INS Arnala is the first unit in a new class of corvettes known as ASW shallow-water craft (ASW SWC). The class is being built by a partnership formed by Garden Reach Shipbuilders and Engineers (GRSE) and Larsen and Toubro (L&T) as replacements for the Indian Navy’s 1980s-designed Abhay-class corvettes.

GRSE and L&T are responsible for delivering Arnala and seven of her sister ships while Cochin Shipyard will supply another eight ASW SWCs, which will be known as the Mahe-class. All 16 ships will each have more than 80 per cent indigenous content in line with the Indian Government’s “make in India” initiative.

Named after an island off the coast of Maharashtra, Arnala has a length of 77.6 metres (255 feet), a beam of 11.26 metres (36.94 feet), a draught of only 2.7 metres (8.9 feet), a displacement of 900 tons, a gross tonnage of 1,490, and space for seven officers and 50 enlisted sailors.

The propulsion arrangement consists of three diesel engines and waterjets capable of delivering a top speed of 25 knots and a range of 1,800 nautical miles at a cruising speed of 14 knots. The dimensions make the Arnala and her sister ASW SWCs the largest waterjet-equipped vessels to be acquired by the Indian Navy.

Multi-role surface combatant for both coastal and offshore environments

Arnala is capable of full-scale, sub-surface surveillance of coastal waters and up to 200 nautical miles from shore as well as search and attack. The vessel can also carry out ASW operations in coordination with aircraft. Secondary missions will include search and rescue (SAR), port protection minelaying, and limited air defence.

The vessel boasts armament consisting of lightweight torpedoes launched from port and starboard triple tubes, ASW rockets fired from a forward-mounted RBU-6000 launcher, a GRSE-developed 30mm naval gun, and two Browning M2 12.7mm machine guns fitted on remote controlled stabilised mounts.

Advanced electronics suite

The electronics suite meanwhile includes navigation radars, hull-mounted and low-frequency variable depth sonars, power management systems, an integrated bridge, an AIS, an echosounder, an automatic weather observation system, a battle damage control system, and a combat management system.

Space is also available for one rigid inflatable boat to assist in SAR.

The eight Arnala-class ASW SWCs are all classed by the Indian Register of Shipping. All are scheduled to be in service with the Indian Navy by 2026 along with their Mahe-class counterparts.