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S 55 Sindhughosh Class
Sov Kilo

An explosion resulting in a major fire took place on board INS Sindhurakshak, a Kilo class submarine of the Indian Navy, shortly after midnight on 14 August 2013. Fire tenders from the Naval Dockyard as well as the Mumbai Fire Brigade were immediately pressed into action. However, due to the damage suffered as a result of the explosion, the submarine had submerged at her berth with only a portion visible above the surface.

The 18 persons on board the submarine at the time of the accident were killed. Nearly 16 hours after submarine INS SINDHURAKSHAK caught fire at naval dockyard in Mumbai, divers were able to enter the submarine. The diesel-powered, Russian-built submarine INS Sindhurakshak, was inducted into the navy earlier this year after undergoing a two-and-one-half-year, $80 million upgrade in Russia. It had suffered an accident before it went for a retrofit: in 2010 one sailor was killed on the vessel, apparently due to a hydrogen leak. The explosion left the submarine unable to return to full operational capability.

Four years after an accident and resultant operational issues, the Indian Navy sank the Russian-built Kilo-class submarine INS Sindhurakshak in June 2017. the US-based Resolve Marine Group had salvaged INS Sindhurakshak. The submarine's resting point is 3,000 meters below the surface.

In the late 1970s, the Russian side was requested to suggest replacements for the eight Foxtrot class submarines. A request was also made for Tube Launched Missiles (TLMs) in 1978. The Russian response was that the 877 EKM design was on the drawing board and that TLMs would take some time to develop and be off ered. As regards the submarines, India should make up its mind quickly so that its requirements could be bulked with others. It was decided to await a thorough evaluation.

In 1983, an Indian team evaluated the ultra-quiet 877 EKM and concluded that its technology was a generation ahead of the preceding i641s and that its performance as a hunter-killer SSK was comparable to that of the German HDW 1500 SSK design that had been selected in 1981 for indigenous production at Mazagon Docks Ltd in Bombay. In 1984, a contract was signed for six of these submarines which were later designated as the Sindhughosh class. The seventh submarine was contracted for in 1987 and the eighth in 1988. These eight submarines were commissioned in 32 months between 1986 and 1990. On the one hand, this rapid delivery swiftly restored diminishing force levels. On the other hand, this bunched induction resulted later in the bunching of their MRs, which further overloaded the Navys Medium Refit capability.

The tear-drop hull, being hydro-dynamically the best underwater configuration, the underwater management of the EKM was excellent. The EKM had auto diving control the crew could steer the submarine automatically even from the fire control computer. The hydroplanes were located in the midships portion where there was no interference with the sonar. The submarine hull was covered with rubber tiles which absorbed the acoustic energy of adversary sonar transmissions. The radiated noise (self-noise) of the submarine was very low.

A total of ten diesel-powered 'Project 877' submarines, known in India as the the EKM or Sindhu class, have been built under a contract between Rosvooruzhenie and the Indian Defense Ministry. They have a displacement of 3,000 tons, a maximum diving depth of 300 meters, speed of up to 18 knots, and is able to operate solo for 45 days with a crew of 53.

The first Kilo-class submarines of project 877 were built in the USSR in 1979. In 1994, the Russian side off ered TLM capable submarines. In 1997, orders were placed for two of these submarines. The ninth submarine did not have TLM but was an improved version that had remedied the teething problems experienced in the earlier 8. The 10th submarine had the long awaited tube TLM capability. In due course, most of the initial 9 EKMs were progressively upgraded with TLMs.

The first four submarines of the Sindhughosh class (Russian Project 877 EKM, NATO designation Kilo class) were constituted as the 11th Submarine Squadron and based at Vizag to facilitate the training of EKM commissioning and replacement crews. The next four Sindhughosh class Russian 877 EKM submarines that arrived by 1990 were based in Bombay and constituted the 12th Submarine Squadron. The 9th Submarine squadron based in Bombay gradually relocated to Vizag. The last two, MDL-built SSK submarines joined the 10th Submarine Squadron in 1992 and 1994.

In January 1988, the Navy sought to add one 'K' class submarine to their fleet and while processing the case for Government sanction, suggested that plan for acquisition of more 'S' class submarines should be dropped as the 'K' class was superior. Accordingly, the proposal was accepted in March 1988 and one 'K' class submarine was imported at a cost of Rs 120.26 crore and commissioned in December 1990.

It was, however, noticed in audit that opinion of the Navy about the superiority of 'K' class submarines was not based on an actual assessment of combat capability of the submarines. Even at the time of submitting the proposal in January 1988 to augment the 'K' class fleet of submarines, a full comparison of the capabilities of 'S' and 'K' class had not been carried out although both the classes were available with the Navy for a considerable time. When this exercise was completed in 1988, the Navy realised that 'K' class was a highly under-powered vessel although it had excellent sonar capability, modem long range torpedoes and a superior hull design. As a result, the vessel was later assessed to be inferior in combat capability but no attempt was made to forestall procurement of the 'K' class vessel which was already processed.

Instead, in 1992, the Navy ambitiously proposed upgradation and modernisation of the 'K' class submarines in a phased manner at a cost of Rs 4000 crore. It is curious to note that the proposed cost of upgradation was nearly 500 per cent of the cost of acquisition. No justification has been provided by the Navy as to why an inferior class of submarines should be procured in the first place, which requires upgradation at an exorbitant cost. So far this proposal had not been acceded to, but the Ministry had provided Rs 1.50 crore between July 1994 and February 1996 to improve the habitability and performance of certain equipment on board of this class of submarines.

The Indian Navy ordered two Kilo Class submarines from Russia in 1997. The first submarine, the Sindhurakshak, was commissioned in Dec 1997 at St. Petersburg, Russia and was of the Type 877 EKM design. The second submarine the Sindhushastra was also commissioned in St. Petersburg, but in July 2000, but is believed to be of the Type 636 design.

In EKM submarines, the periodicity of Medium Refits was five years (instead of six-years as in the case of the earlier Kalvari/Vela class). From 1997 onwards, EKM submarines started going to Russia for 5-yearly repairs-cum-modernisation. The Sindhuvir, which was originally commissioned in 1988, underwent a mid-life refit from June 1997 thru April 1999. This was followed by Sindhuratna (also commissioned in 1988) between 2000 and 2002 and followed by Sindhughosh (commissioned 1986) between 2003 and 2004.

The Sindhukesari and the Sindhura returned to Mumbai in 2002 after their mid-life refits were completed in Russia. INS Sindhukesari, one of the frontline submarines of Indian Navy, returned to Mumbai after completing a major refit and modernisation package in Russia. This modern submarine with enhanced sensor capabilities and extended weapon ranges is a vital element of Indian maritime force adding teeth to silent underwater service. The Sindhuratna began its refit in 2000 and returned to India in Summer 2002. Sindhugosh underwent her refit in Vizag from 1997 to 2000.

Sindhushastra, the tenth and final unit, delivered to India in 2000, was the first to be equipped with the Klab ZM-54E [SS-N-27] antiship cruise missiles with a range of 220 km. Following retro-fits, at least five and possibly six of the Indian Kilo contingent will be equipped with the 3M-53E Klub-S antiship missiles, which India plans to modify for land-attack missions.

Government has an approved submarine building plan which is being progressed. Further, a proposal for extending the service life of six submarines was finalized in 2015. After nearly two years in discussions, the Indian government has finally agreed to push through a long-standing Indian Navy demand for a life extension of at least four of its eight effectively remaining Kilo-class submarines.

The Indian Navy is looking to squeeze some more life out of its two decade old kilo class submarines, signing up a contract with Russia to extend the service life of the boats to 35 years. Struggling with a depleted underwater fleet, the Navy has finalized a contract with Russian shipbuilder Zvezdochka and will be sending the first submarine for the refit in June 2016. The extensive refit, the value for which is pegged at Rs 5,000 crore for a total of four submarines, will not only extend the life of the boats but will also upgrade their combat potential. The first submarine to be sent is the INS Sindhukesari that will be fitted with Klub land attack cruise missile.

While the first of the four submarines will be upgraded at Severodvinsk in Russia, the plan is to upgrade the remaining three in an Indian yard as part of the 'Make in India' initiative. Zvezdochka, which is the Russian yard tasked with the modernization process, has already tied up with Reliance Defence to upgrade the submarines at the Pipavav yard in Gujarat. However, the Navy awarded the upgrade contract for the first submarine only. A decision on the remaining will be taken after a review of Indian yards and their capability to undertake the complex upgrade. The Sindhukesari will be the first of the Indian Kilo class submarines to undergo the "life extension upgrade to 35 years" even though the Russian Navy has done this 'second refit' to its fleet. Upon reflection, it seems likely that the life extension is for a decade of further service beyond that already undertaken by the time the boats entered refit, since the first eight unts were commissioned in the 1986-1991 timeframe. Thus the refits undertaken in the 2001-2005 timeframe came after little more than a decade of service, while the 2017-2019 refits came after the boats had already reached nearly three decades of service.

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Page last modified: 08-01-2021 13:54:36 ZULU