The fully-armed submarine was to go on a long patrol

While the jury is out on what really triggered the crippling blasts that wrecked the naval submarine INS Sindhurakshak in Mumbai on Tuesday night, chances of a sabotage causing it are giving the Navy the jitters.

Given that the fully-armed submarine was at the high-security Naval Dockyard in preparation for a long patrol on Wednesday evening, only an insider could have done some foul play, if that was the case, indicate Navy sources.

The severity of the twin explosions that gutted the forward area of the kilo-class submarine, which was handed over to India after a $ 150-million upgrade in January this year, points to torpedo burst, as the flame bore an unmistakable orange hue, sources say.

Hydrogen the trigger?

Live ammunition was being loaded on the boat till 10.30 p.m. on Tuesday in view of the patrol on Wednesday. “There must have been frenetic activity going on. Hydrogen released while charging its 800 kg batteries could have caused the first explosion, which would have set off the torpedo burst,” said an officer.

While the Navy Chief Admiral D.K. Joshi did not fully rule out sabotage, seasoned submariners like Vice-Admiral (retd) K.N. Sushil, former chief of the Southern Naval Command, consider the scenario “very very dangerous.”

“I don’t even want to think of such a possibility,” said Mr. Sushil. It would mean someone had penetrated the crew, which was highly unlikely.

He said if there was just a hydrogen blast, it would not have been this disastrous and damaging. But if that were the case, it somehow caused the oxygen torpedoes [torpedoes having oxygen compressed to 200 bars instead of compressed air as fuel oxidizer in its propulsion system] to explode. It could also be conjectured that electric short circuit or something caused the oxygen to blow out. Shockingly, the sequence of events hardly explained anything, he told The Hindu.

The missile warhead couldn’t have gone off as missiles “are loaded into the torpedo tubes in nitrogen-pressured containers.” To a question on chances of sabotage, he said someone adept at handling torpedoes executing it could not be ruled out.

Vice-Admiral (retd) A.K. Singh, who commanded nuclear submarine INS Chakra and headed the Eastern Naval Command, told The Hindu that there could be two surmises. “Submarine batteries give out hydrogen while charging. There are devices to neutralise hydrogen thus released, as its concentration above 4 per cent can set off a blast. Two decks above this is the weapon compartment and the fire caused the warheads to explode. Another possibility is that something went terribly wrong while arming the boat,” he said.

Former Vice-Chief of the Navy Vice-Admiral (retd) Raman P. Suthan termed ‘highly unlikely’ the sabotage theory, citing that access to submarines was highly restricted.

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