In the wake of the blasts on INS Sindhurakshak, the Navy has ordered extensive checks on weapon-related safety systems on all its submarines, defence minister AK Antony told Lok Sabha.
Making a statement in Lok Sabha on the incident in Mumbai on Saturday, he said preliminary investigations have indicated that the blasts on the submarine were caused by "possible ignition" of armament.
Reading out the statement amid din over coal file issue, he said as the "explosion and resultant damage were near instantaneous, the 18 personnel could not evacuate. Although full details are yet to emerge, the rapidity and intensity of explosion and resultant damage sustained by the submarine indicate that the personnel would not have survived."
"After the accident, the Navy has ordered an audit of standard operating procedures (SOPs) on all operational submarines and extensive checks on the weapon-related safety systems," Antony said.
He said "preliminary investigations indicate that the explosion was due to the possible ignition of armament. The cause of ignition is, however, yet to be established. Forensic examination would throw more light into the possible cause of ignition."
He said this would be possible only after the "partially submerged" submarine is afloat and dewatered. "A Board of Inquiry with all relevant specialists has been constituted to investigate the likely causes of the accident at the earliest."
Antony said globally-renowned salvage agencies have been approached and they are undertaking survey for salvage operations.
"There is also an offer of help from Russia, where the refit and upgrade of the submarine had been undertaken," he said.
The defence minister said the submarine is presently resting on its bottom and "partially submerged" next to the jetty where the incident took place.
"Diving operations by the Navy are in progress round the clock to attempt search for the personnel, assess the damage and also attempt to arrest leakages and ensure dewatering," he said.
The divers from Navy have entered the submarine but their access has remained limited to only some parts of the submarine due to heavy damage and flooding of compartments with obstructions from debris and structural distortions, Antony said.
The minister said breaches have been indicated in the "watertight integrity in the forward portion of the submarine hull" after inserting high pressure air as part of efforts to identify possible areas of water ingress.
"Efforts have been made to dewater the flooded compartments using high capacity pumps. However, 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," Antony said.
On the support for families of the submarine's duty crew inside the submarine at the time of accident, he said, "I would like to assure that all support, assistance and counselling will be provided to families of all personnel. A family cell has been formed at the Western Naval Command."
"We convey our deepest condolences to the families of Navy personnel who have made the supreme sacrifice in the line of duty," the minister said.