"Mishandling of weapons led to explosion which destroyed submarine INS Sindhurakshak. The fatal accident happened because laid down procedure were not followed," disclosed Navy chief.
An explosion onboard Sindhurakshak on August 14 last year had resulted in the death of 18 Navy personnel. Navy officials said the submarine may not be seaworthy, even after refits.
"The salvors have lifted the submarine and it is currently resting on a pontoon and will be soon anchored on the dry dock of the Naval Dockyard," said a Navy official.
"We doubt that (if) it may be seaworthy after all the refits as fire was caused because of explosion of many missiles and torpedos and it would have damaged the hulk and the decommissioning seems to be imminent," the official said.
Also read: What is INS Sindhurakshak?
Indian arm of US-based M/S Resolve Marine won the contract to salvage the submarine in January. A 160-days deadline was set for it to complete the job.
The senior Navy official also said that once the submarine is handed over to the Navy, it will be subjected to two sets of tests.
"The first test is to ascertain the cause of the accident and the other to decide the nature of the work to be undertaken to make it seaworthy," the official said.
Navy officials also said that though a Board of Inquiry was conducted and an interim report was submitted detailing out six probable causes of the accident, another study will be conducted by the same Rear-Admiral level officer who conducted the earlier inquiry.
"The Naval Dockyard will conduct a probe to decide the submarine's seaworthiness and will see if any refits are to be undertaken or if it should be decommissioned. The cost incurred in the repairs will also be studied," said an officer.
The officials also said that a sonography of the hulk of the submarine will be conducted to determine the extent of damage. The electric cables will be tested and a study will be also conducted on the extent of corrosion of the metal.
(With inputs from agencies)