INS Sindhudhvaj (S56) is a Sindhughosh-class submarine of the Indian Navy

The Indian Navy is decommissioning the INS Sindhudhvaj, a Kilo-class submarine, sometime this year. It will set in motion a process of phasing out of a class of boats that have formed the backbone of the navy’s underseas fleet for nearly three decades. The decommissioning ceremony was due in Mumbai this April but is now delayed by two months awaiting clearances from the defence ministry. The Sindhudhvaj was acquired from the Soviet Union in 1987. With its retirement, the navy’s submarine arm dips to 14 units. Seven of these submarines are of the Kilo class variety.

Dubbed the ‘Kilo’ class by NATO, the Project 877 EKMs are one of the world’s commonly visible conventional submarines with 62 units currently in service across nine navies in the world. India acquired eight such subs between 1986 and 1991. It later acquired two more submarines from the Russian Federation, between 1998 and 2000. They were the navy’s first submarines that could fire anti-ship and land attack cruise missiles from beneath the surface, making them a formidable force multiplier in the naval fleet.

One unit, the INS Sindhurakshak, was lost in an accident in 2013 and a second, the Sindhuvir, was transferred to the Myanmar navy last year.

The Kilos are being replaced by the French Scorpene submarines which are being built under licence by the Mazagon Dock Shipbuilders Ltd. Three of the ‘Kalvari class’ have so far been inducted; the third, the INS Karanj, was commissioned in Mumbai on March 11 this year. Three more Scorpenes, the Vela, Vagir and Vagsheer are to be commissioned by 2023. But these will not meet the navy’s requirements for a force of 24 conventional submarines. The closest it got to that figure was in 1995 when it had 20 submarines. Since then, the pace of retirements has outstripped acquisitions. The navy’s submarine arm is now staring at a lost decade between 2021 and 2030 where its fleet will stagnate.

Mazagon Docks Ltd, which built the Scorpenes, is believed to have made an offer for a further three units to be built at its Mumbai yard, but this has not found favour with the navy. Nor has a new offer for six Project 636 improved Kilos from Russia’s Rosoboronexport (believed to have been made last year). The navy is focused on its future conventional submarines--the Project 75 ‘India’ boats to be made by an Indian firm in partnership with a foreign original equipment manufacturer (OEM). Project 75, first proposed nearly two decades ago, is yet to deliver a single unit. Legal issues have delayed the issue of the Request for Proposals from the MoD to a ‘strategic partnership’ between an Indian yard and a foreign OEM. Even if the project moves at warp speed, it will take at least eight years before a new submarine joins the fleet.

As a stop-gap, three Kilo class submarines have been put through a second medium refit (MR) at a Russian shipyard with a fourth scheduled to depart this year. A medium refit is usually done only once in the 30-year life of a submarine. The second refit slaps on an additional decade to the submarine hull taking it to around 40 years. These MRs were initiated around five years ago when it became increasingly clear that the navy was not getting new submarines in a hurry. With the delays in Project 75I and the dip in the force levels, the navy could well be forced to take a call to upgrade the only three Kilos which have not had a second medium refit to enable them to serve through the lost decade.