Why in news?

The Navy’s Kilo-class submarine, INS Sindhudhvaj, was decommissioned from service at Visakhapatnam after 35 years in service. With this, the Navy now has 15 conventional submarines in service.

Highlights:

• The decommissioning of the submarine has been delayed by about a year.
• She had many firsts to her credit, including operationalisation of the indigenised sonar USHUS, indigenised satellite communication systems Rukmani and MSS, inertial navigation system, and indigenised torpedo fire control system.
• She also successfully undertook mating and personnel transfer with Deep Submergence Rescue Vessel and was the only submarine to be awarded Chief of Naval Staff (CNS) rolling trophy for Innovation by Prime Minister Narendra Modi.
• Commissioned into the Navy in June 1987, Sindhudhvaj, was one of the 10 Kilo-class submarines India acquired from Russia between 1986 and 2000.
• Of these, INS Sindhurakshak was lost in an accident in Mumbai harbour in August 2013, while Sindhuvir was transferred to Myanmar in 2020, making it the South East Asian nation’s first underwater platform.

Submarines in service

• The Navy’s sub-surface fleet now includes seven Russian Kilo-class submarines, four German HDW submarines, four French Scorpene submarines, and the indigenous nuclear ballistic missile submarine INS Arihant. The last two of the Scorpene class submarines are in various stages of trials and outfitting.

• Efforts for the construction of six advanced submarines under Project-75I have been delayed. With delays in submarine induction, the Kilo submarines and HDW submarines are being put through the Medium Refit Life Certification (MRLC) process to extend their service life.