by Joseph P Chacko

The Russian Navy proposes dismantling the damaged nuclear-powered submarine “Shchuka-B” from Project 971U, which was leased to the Indian Navy and renamed “Chakra-2.”

For budgetary reasons, the Russian Navy’s Main Command has deemed it impractical to repair and modernise the damaged nuclear-powered submarine “Nerpa,” which is now at one of the shipyards in Vladivostok. Instead, they recommend getting rid of it.

The hulls of Chakra-2 sustained damage when a High-Pressure (HP) air bottle exploded on board in April 2020. Hydro-Acoustic devices and electronic equipment were also impacted. India prematurely terminated the submarine’s leasing agreement following the incident.

Based on my estimation of the accident and the submarine’s state afterwards, the HP air system had degraded, which meant it needed to be replaced completely. Fixing the submarine would have cost a lot of time and money, so it might not have been possible economically (Beyond Economic Repair/ BER).

Although the HP Air bottle explosion occurred in a specific location, it was necessary to conduct a comprehensive survey to proceed with the investigation because HP Air is the submarine’s lifeline. Internal corrosion in HP air bottles is a possibility.

The submarine might have had a minimum life of a couple of years and possibly even longer, even after repairs. Russian submarines have a thirty-to-forty-year lifespan.

The INS Chakra returned to Russia on its own power on the surface because of the unreliability of the HP air system. This also shows no problems with the power plant’s dependability.

No Official Statement

Russia or the Indian Navy has not publicly explained the premature return of INS Chakra.

On June 5, the Indian media stated that India’s leased atomic submarine, “Chakra”, had been returned to Russia. The decision was linked to the lease’s expiration date. According to Indian media, the submarine was escorted to Vladivostok by Russian and Indian ships. The submarine had then reached Singapore, and the Indian crew was on board. In 2012, the Indian side leased the submarine.

On Wednesday, June 9, 2021, the Russian news outlet TASS first revealed the cause, citing an insider in the defence sector. According to the report, a high-pressure air bottle on board the submarine “Chakra” (INS Chakra), project 971U “Shchuka-B,” exploded, forcing it to be returned to Russia from India. TASS later withdrew the message at 12:21 Moscow time, claiming it had been released incorrectly.

Initially, the source stated that the event occurred during a deployment in the spring of 2020, damaging the submarine’s light and durable hulls, between which the air bottle was located. Radio-electronic and hydroacoustic weapons were also affected. Following the explosion, Indian specialists repaired both hulls of the submarine, which autonomously went to Russia in the surface position.

As reported by the media, India entered into a contract with Russia in 2019 to lease a nuclear submarine for the Indian Navy for ten years. The agreement was worth three billion dollars. At this point, India had leased a nuclear submarine from Russia for the second time. In 1988 the first one, referred to as “Chakra,” was leased from the Soviet Union for three years.

The construction of the nuclear-powered assault submarine known as “Nerpa,” which has a displacement of 8140 tons, originally started in 1991 at the Amur Shipbuilding Plant. However, due to a lack of funds, the development of the submarine was delayed for more than ten years. In 2000, India and Russia agreed to the long-term lease of the K-152 “Nerpa.” “Nerpa” was technically ready at 86.5% when the agreement was reached and ready to be used. It was planned that a second submarine of the same sort would be developed and then leased to India after it was finished.

Chakra-2 was first damaged during its lease to the Indian Navy on October 3, 2017. At the time, Admiral Sunil Lanba, the Chief of Naval Staff of India, confirmed the incident on December 1, 2017, during a press conference leading up to the Navy Day that year. According to Lanba, the hydroacoustic dome of Chakra 2 was damaged, and two hull panels were displaced.

The catastrophe occurred around the time the submarine was entering the harbour of Visakhapatnam. As reported by TASS, Russia would repair the hydro-acoustic dome of Chakra-2 for $20 Million. The price tag covered the production of replacement panels at their facilities and shipment to India. Finally, the repairs were undertaken by the Indian Navy’s Naval Dock Visakhapatnam (ND(V)), overseen by Russian specialists, and the special shield plates were sent from Russia. The total cost was around $25 Million.