Sindhughosh: The Saga of Tragedies in Deep Waters

INS Sindhurakshak blast
Representative image: Ordnance Blast on INS Sindhurakshak. Artwork ©: KnowYourHeroes/Hrishabh Tiwari




There is no better canvas than the never-ceasing ocean, and there's no artist more capable than the seafarers who splatter vibrant colours across the 'blue tarp'. There is a saying that if anyone can hear the sound of silence, it is indeed the sailors who are present inside the submarine's metallic hull. Indubitably the submariners are among the most qualified and able men in the service trained to beat back any menace. Indian Navy has been fortunate enough to have virtuoso sailors and officers onboard its wide-ranging fleet of submarines, akin to their name "Silent Killers", submersibles move silently in the ocean's darkness protecting the country against enemy threats. With two Nuclear-powered ballistic missile submarines and 15 conventional diesel-electric attack submarines, the Indian Navy stands firm among the world's top and formidable maritime powers. The life underwater has it all, from the thrills of a spy to the terrors of the sea and the sailors who enter the submersible know what's waiting for them. Without sunlight, staying inside diminutive and cramped quarters, dealing with the vagaries of the ocean, the personnel on board the "monster war fish" are always up and ready to face every challenge that the sea throws at them.

But certainly, there are moments when the 'fish is caught in the troubled waters' either due to technical snags or a series of tragic lapses resulting in fatal accidents. Over the last one and half decades, the Indian Navy has had to face more than five accidents, two of which had catastrophic consequences. Indian Navy operates a Kilo-class diesel-electric submarine fleet; Sindhughosh. The fleet of ten submarines was built under 'Project 877 EKM' as a contract between the Ministry of Defence, India and Rosvooruzhenie, a Russian Defence intermediary agency. The Sindhughosh-class subs inducted between 1986 through 2000, ended the Navy's long search for the submarines capable to fire anti-ship and land cruise missiles from beneath the surface. The Sindhughosh-class formed a backbone for the Navy's submarine fleet and amplified the maritime powers of India for the decades to come.

Indian Navy even deployed the Sindhughosh-class submarines very close to Karachi during the 1999 Kargil War; these 'Kilo' subs posed a severe threat to the enemy ships up until the late 2000s when the submarines began to show signs of wear. Although refits and upgrades were done, the underwater fleet seemed to be way past its prime. In January 2008, INS Sindhughosh(S55) collided with a cargo ship and sustained superficial damage to its conning tower; although it did not accumulate much damage, the 22-year-old submarine certainly was not operating at peak efficiency. A second incident happened in the sister submarine of the INS Sindhughosh, the INS Sindhurakshak(S63), where a major fire broke out due to faulty batteries, killing a technician and injuring a few others.

It took two and a half years for INS Sindhurakshak to return to service after refitting and overhauling the damage. Things got even worse for the Indian Navy when the INS Sindhurakshak, which was berthed at the Bombay Naval Dockyards after undergoing refits, was sunk by a significant explosion. The fire, followed by ordnance blast, embedded the submarine with its 18 member crew in Dockyard's seabed. Just when the saga of tragedies seemed to end, another mishap befell onboard INS Sindhuratna(S59). What started as a cloud of smoke in the electrical compartment of the INS Sindhuratna ended up killing two officers Lt Cdr Kapish Muwal and Lt Cdr Manorajan Kumar. After all these fatal accidents, the MoD seems to be taking cognizance of the situation and acting rapidly to replace the old-gen 'Kilo' subs with indigenous Scorpene-class submarines. In this article, we shall visit all the tragedies encountered by the Sindhughosh-class submarines of the Indian Navy.

Sindhughosh-class Submarines
Sindhughosh-class diesel-electric attack submarine. Artwork: KnowYourHeroes/Hrishabh Tiwari

Besides looking for conventional submarines with anti-submarine warfare(ASW) and anti-surface-ship warfare(ASuW) capabilities, the Indian Navy was also desirous of replacing its Kalvari-class (Foxtrot-class) submarines with a similar fleet. The MoD and Indian Navy then turned to Russia for procuring a fleet of submarines. Designed and built at the Admiralty Shipyard in St. Petersburg, Russia, the SSK Kilo-class submarines manufactured under 'Project 877 EKM' were precisely what India had been looking for. In 1986, the Indian Ministry of Defence placed an order for eight submarines with Rosvooruzhenie, Russia's defence import & export intermediary agency. These submarines were acquired between 1986 and 1991. Later, between 1997 and 2000, India acquired two more submarines of the same Kilo-class from the Russian Federation.

The first of the Sindhughosh-class submarines acquired by the Indian Navy, the INS Sindhughosh(S55), was launched on April 30, 1986. Subsequently, other submarines joined in to form one of the most lethal conventional attack underwater fleets. Dubbed by NATO as 'Kilo-class', these diesel-electric attack submarines have a length of 72.6m with a capacity to carry 52 crew members. Six 533mm torpedo tubes and the ability to store 18 heavyweight torpedoes made these submarines one of a kind, and the fact that it could reach depths of 300m with an endurance of 45 days moulded this fleet into the Indian Navy's premier war machine of shallow waters.

Sindhughosh-class Submarine
Sindhughosh-class Submarine characteristics. Artwork: KnowYourHeroes/Hrishabh Tiwari

The Sindhughosh-class(Kilo-class) submarines were among the quietest and most cost-effective submarines ever built by the Russians, giving developing countries access to an underwater fighting fleet that was considered a luxury and only cherished by the superpower nations. Although these subs were doing an excellent job of providing 'best-in-class' vessels at less expense, the major drawback lied in the powering systems. Because the Sindhughosh-class submarines use a combination of diesel generators and electric batteries for propulsion, they have short-range and low endurance compared to Nuclear-powered vessels. These Kilo subs use 'heavy-duty lead-acid' batteries to power the propeller. Hence, the submarines have to resurface to 'over-charge' the batteries in the absence of an AIP system, making them vulnerable to detection. It can also be seen as a blessing since these vessels are non-nuclear; they produce insignificant acoustics making them hard to track or colloquially making them the "black-holes"(stealthy).

As the successors to the Vela and Kalvari class submarines, the Sindhughosh vessels served as the core of the Indian Navy's underwater fleet for close to thirty years, but their ageing has been apparent with signs indicating diminishing performance during combat operations. A total of seven Sindhughosh-class submarines have been refitted in Russia, while two vessels were refitted at Vizag, as part of efforts to maintain the Indian Navy's ever depleting submarine strength. Although a Kilo-class submarine has a lifespan of 25 to 30 years, the INS Sindhughosh commissioned in 1986 had already done about 22 years of service until 2008. Despite one life extension and mid-life refittings at Zvezdochka shipyard between 2002-2005, the INS Sindhughosh is currently undergoing an upgrade under the "Major Refit and Life Certification" programme along with four other Kilo-class vessels. Former officials of the Ministry of Defence have often failed to upgrade machines and equipment in time, resulting in potentially life-threatening situations for personnel of the Armed Forces, sometimes even ending with casualties. The Sindhughosh-class submarines have been the prime example of MoD officials neglect that has resulted in 20 personnel of the Indian Navy losing their lives on board the ageing submarines.

INS Sindhughosh(S55) collision with M.V. Leeds Castle Cargo Ship


The collision between the INS Sindhughosh and the cargo ship M.V. Leeds Castle on January 7, 2008, was the first warning sign of the ageing 'Kilo' fleet. The incident took place when the cargo ship M.V. Leeds Castle was traversing the Arabian sea en route from port Mundra to Mumbai. At 1325 hrs, INS Sindhughosh engaged in a Naval exercise about 740 km north of Mumbai was apparently surfacing in a 'silent mode' with its radio and radar switched off when the upper hull of the submarine made contact with Panama registered Cargo ship. The incident occurred some 25 miles south of Diu head and damaged the railings, mast and antennae of the submarine at the conning tower level. An initial investigation revealed that the navigational equipment was not performing at their peak efficiency since they were not regularly monitored. Additionally, the submarine was outside the "submarine exercise area" as marked on the navigational map. Although the submarine did not suffer severe damage, there were shreds of evidence of an aggregation of several serious issues with the old fish. INS Sindhughosh went under a month-long overhaul following the minor damage of the conning tower and soon returned to the service.

Collision between INS Sindhughosh and MV Leeds Castle
Collision between INS Sindhughosh and MV Leeds Castle

Battery malfunction costs a life


INS Sindhurakshak bearing the pennant number S-63 was ninth among the ten submarines of the Sindhughosh fleet. Commissioned into the Indian Navy in 1997, the S-63 vessel was truly living to its name; Sindhurakshak, the protector of the sea. It was even deployed very close to Karachi ports during the Kargil war. Being extremely silent, the Sindhurakshak vessel was a nightmare for enemy warships, and in the event of a naval confrontation in 1999, the S-63 would have caused Pakistan the most damage. Having been in service for more than a decade, the vessel was reasonably young compared to other subs of the same Kilo-class and it still owned fresh legs or propellers, to be precise. But misfortune struck the vessel when it was parked in the shallow waters of Vizag Harbour for routine maintenance. In the late evening of February 26, 2010, the sub-aquatic war machine was undergoing some maintenance in the electrical compartment where the heavy-duty lead-acid batteries are stored. In the 2,300-ton Kilo-class vessel, there are as many as 500 of these batteries that power the sub's propeller when the diesel runs out. As part of the maintenance work, the batteries of the vessel were manually being checked because the Sindhughosh-class submarine is not equipped with an automatic battery inspection system. Even during the recharge operation, the lead-acid batteries have to be manually checked throughout the process of over-charging that happens once in few months.

As the technicians inspected the accumulators, a defective battery malfunctioned, triggering a large explosion that quickly filled the vessel's electric compartment with smoke and fire. Midst the whole mishap, few technicians were able to flee from the electric compartment but ill-fated LEMP Kump Dan, an electrical technician was caught in the fire plumes. When the situation was brought under control, the mortal remains of Kump Dan was recovered. The incident saw major backlash from the Naval community demanding refits and upgrades for the vessel. According to theory, the hydrogen built-up during the charging process is sucked out by blowers, the efficiency of the blowers onboard a submarine can be affected if a proper vacuity is not maintained in the exhaust's pathway. The clutter in the exhaust causes the hydrogen to settle in petite sacs which can be triggered by a small spark and in this case, the fire mishap could have been ignited by the same hydrogen pockets.

INS Sindhurakshak (S 63). Indian Navy submarine
Representative image: INS Sindhurakshak(S-63) berthed at Vizag Harbour. Artwork: KnowYourHeroes/Hrishabh Tiwari

The 'Big Fish' goes down


Following the mishap at Vizag, the Ministry of Defence and the Indian Navy decided to give INS Sindhurakshak a refit and upgrade it with newer equipment. Ship repairing centre Zvezdochka in Russia and the Ministry of Defence agreed to give the vessel a new lease of life by refitting and upgrading its old-gen equipment. The S-63 embarked on its journey from Vizag and reached western Russia's Zvezdochka shipyard on the White Sea where the work of repair commenced from August 9, 2010, under Project 08773. INS Sindhurakshak had seemingly bloomed with new life after undergoing an overhaul and upgrade for 24 months. The submarine had been equipped with new sensors, safety equipment, communication gear, and most importantly, modern Klub-S anti-shipping and land-attack cruise missiles, so it looked as deadly as ever. The vessel was also modernised with the DRDO's indigenously built USHUS Submarine Sonar Suite while the communication system was enhanced using the CCS-MK-II system and Porpoise radio-locating radar that had added at least 10 years of life into the submarine. After a payoff of $80 million and 24 months, INS Sindhurakshak came off the slips at Russian Dockyard marking the completion of the mid-life refit and upgrade programme. The submarine was handed over to the Indian Navy on January 27, 2013, after an extensive 3-month sea trial, and under the command of Commander Rajesh Ramkumar, it became the first Indian sub to sail under the ice.

INS Sindhurakshak refit in Russia
INS Sindhurakshak clicked at ports of different nations on its way back to India after undergoing 24 month-long refit.

Indian Navy's recently modified INS Sindhurakshak started its voyage back to home waters making port calls at different countries along the way. But it seemed as if the curse would follow the submarine to its grave. In March 2013, a severe storm hit INS Sindhurakshak in the Mediterranean Sea near Alexandria as she returned from Western Russia. Due to the storm's severity, Alexandria port authorities weren't able to send a tugboat, and the shallow waters prevented the submarine from diving. In response, India's Ministry of External Affairs placed an urgent call to the Egyptian authorities, who dispatched a tugboat and ferried the vessel to port thence averting any mishap. After a tiring journey of over 10,000 miles, the submarine returned safely to Bombay Naval Dockyards.

August 14, 2013, a day that'll forever haunt the Indian Navy. After returning from refits, the INS Sindhurakshak was berthed at Naval Dockyards in the famous South Bombay neighbourhood, impatiently awaiting her return to service to embark on the next deployment. In addition to being fully armed with missiles and torpedoes, INS Sindhurakshak was moored next to its elder sister, INS Sindhughosh, in a very cramped space near the Lion's Gate of Naval Dockyard. It may have been a quarter-hour past midnight, most of the rush, flurry and traffic of the chaotic Coloba neighbourhood had ceased, people in the city were ready for bed when the explosion that lit up the whole South Bombay shook everyone to the core. One, two, maybe three major ear-deafening blasts with angry fire plumes rising up in the sky could be perceived from miles away. "Is it another terrorist attack on this city," the residents who rushed to their houses reasoned. The eye-witnesses would later define the scenes at Naval Dockyard as a 'portal of hell' that had been opened at the sea. Nobody was sure, what had just happened, those observing the blast from far away could see a ball of fire that rose angrily in the blue moon sky. Until late in the night, the whole country would come to know what the blasts really were.

INS Sindhurakshak blast visuals
INS Sindhurakshak blast visuals

A small explosion followed by two major ordnance blasts on the armed INS Sindhurakshak sank the submarine 15 meters deep at its berth with only the conning tower visible above the water surface. As the details of the horrific incident emerged, it sent thuds of shockwave throughout the country, 18 crew members were present inside the sub's hull when the catastrophic explosion took place. Three personnel who were on top of the submarine managed to jump to safety but were too shocked to make any statement. "There were two to three explosions and the night sky lit up briefly. There was a lot of smoke and I thought it was some major repair work," said eyewitness Dharmendra Jaiswal, a sanitation worker. As prayers began pouring in for the safety of the trapped personnel, a miracle seemed possible. While the fire flames were put out in few hours, the main hatch of the submarine would be opened only after 48 hours. As everyone had feared, none among the 18 member crew survived. The explosion triggered in the front compartment twisted, bent and crumpled the submarine and water entered through the openings, the INS Sindhughosh berthed very close to Sindhurakshak in the congested Dockyard also sustained minor damage due to the fire plumes.

“Since none of the officers and sailors present inside the submarine survived, it has not been possible to attribute any blame to any individual for failure or negligence, if any,” Parrikar has said in a written reply in the Rajya Sabha. Lessons learnt from the reports of the Board’s of Inquiry (BoI) are implemented appropriately. Corrective steps have been taken by Naval Headquarters with extensive checks on weapon-related safety systems and audit of Standard Operating Procedures on all operational naval units," said the then Defence Minister Manohar Parrikar in a reply in Rajya Sabha.

The loss of 18 highly trained and able submariners in service was devastating while the loss of a submarine that was not at war was a major setback for the Navy that had already been struggling to maintain its depleting submarine strength. A court of enquiry was ordered to probe the reason behind the explosion and the sabotage angle too was taken into account. The preliminary report stated that the explosion may have been caused by "an accident or inadvertent mishandling of ammunition". The probe concluded stating that "Submarine authorities concerned didn’t properly assess the crew fatigue, besides, the submarine was holding ammunition nearing life expiry". Whatever may have been the reason for the catastrophic tragedy but there was no one to be blamed, not a single crew member on board the INS Sindhurakshak survived to tell their side of the tale. Taking moral responsibility for the mishap, the then Navy chief, Admiral Devendra Kumar Joshi resigned. INS Sindhurakshak once a deadly hunter in the deep waters had now become the graveyard for its own crew members, the vessel was fished out to the surface on June 6, 2014, after a complex operation by US-based Marine Resolve Group which was paid 240 crores and given a time frame of 160 days. Initially, the Indian Navy was hopeful of resurrecting the vessel but after a lot of brainstorming by the officeholders, it was decided to salvage the carcass of the vessel. After using the submarine for a brief period to train marine commandos, the INS Sindhurakshak was bid final adieu and sunk in the Arabian waters in June 2017.

The Indian Navy performed the last rites of all the 18 crew members who lost their lives on board the INS Sindhurakshak.

  • Lieutenant Commander Nikhilesh Pal

  • Lieutenant Commander Alok Kumar

  • Lieutenant Commander R Venkitaraj

  • Petty Officer Sanjeev Kumar

  • Petty Officer KC Upadhya

  • Petty Officer Timothy Sinha