Preliminary investigations into the sinking of INS Sindhurakshak have revealed that the "near-simultaneous" explosions that preceded a fire which engulfed the submarine were caused by the possible ignition of its armaments, Defence Minister AK Antony said on Monday.
Making a statement in the Rajya Sabha, the minister said that cause of ignition is yet to be established. "Initial assessments indicate that an internal explosion occurred in the forward compartment of the submarine where ordinance was stowed, resulting in further near-simultaneous explosions and major fire on board INS Sindhurakshak," he said.
Antony said that explosion and resultant damage were near instantaneous and 18 naval personnel, including three officers, inside the submarine "could not evacuate."
He said that the submarine was rocked by a fire in the intervening night of Aug 13-14 at the Naval dockyard in Mumbai. Antony had visited Mumbai Aug 14 to obtain a first-hand account of the situation.
"Preliminary investigations indicate that the explosion was due to the possible ignition of armament. The cause of ignition is however yet to be established," Antony said. He said visual and forensic examination would throw more light on the possible cause of ignition.
"This will be possible only after the submarine is afloat and dewatered. A board of inquiry with all relevant specialists has been constituted to investigate the likely causes of accident at the earliest," he said.
Antony said extensive checks on weapons-related safety systems and audit of standard operating procedures have been ordered on all operational submarines of the Indian Navy.
He said though full details were yet to emerge, the rapidity and intensity of the explosions and the resultant damage sustained by the submarines indicated that none of those aboard would have survived.
"We are deeply saddened by the incident and the resultant loss of lives. I would like to assure that all support, assistance and counselling will be provided to the families of the 18 naval personnel. A special family cell has been formed at Western Naval Command in Mumbai for this purpose," Antony said, conveying his deepest condolences to the affected families.
He said naval divers have been able to enter the submarine and access only some parts of the vessel due to heavy damage and flooding of compartments and obstruction from debris and structural distortions.
He said diving operations by the Indian Navy were in progress round-the-clock to search for personnel, assess the damage and also attempt to arrest leakages and ensure dewatering.
Antony said efforts have been made to de-water the flooded compartments using high-capacity pumps but there has been no discernible change in the water level inside the submarine, indicating likelihood of ingress of water through openings due to structural damage.
"Further efforts have been made to identify possible areas of water ingress by inserting high pressure air. These have indicated breach of watertight integrity in the forward portion of the submarine hull. Globally renowned professional salvage agencies have been approached and they are undertaking the survey for salvage operations," Antony said.
He said there was also an offer of help from Russia, where the vessel's refit and upgrade had been undertaken. Antony said the submarine was resting on the bottom and was partially submerged next to the jetty where the incident took place.
The minister said that a minor fire was also observed on the upper casing of INS Sindhughosh, which was berthed alongside INS Sindhurakshak and was brought under control.