A safe under-keel clearance margin required to steer warships to the harbour may not be available if the seabed is not excavated periodically, raising the chances of vessels running aground. At least two warships, including a submarine, have run aground in recent weeks while returning to the harbour. Under-keel clearance is the vertical distance between the lowest part of the ship’s hull and the seabed.
Full-scale dredging operations in the navigation channel serving the naval dockyard began on December 12, 2013, at least three years behind schedule. Former navy chief Admiral Arun Prakash said the harbour should be dredged at least once a year. Navy officials blamed bureaucrats for delaying financial clearances and stalling the Rs80 crore project to ensure continuous availability of desired depths in the channel.
“Realising the gravity of the situation, the western naval command had to overrule its financial advisors. Dredging is vital to ensure a warship’s keel is kept clear of the seabed," the top official said.
The commanding officer of INS Betwa was stripped of his position after his guided missile frigate ran aground on January 4. Barely two weeks later, INS Sindhughosh hit the seabed; prompting the navy to order a probe.
Sources said that while delay in carrying out dredging may have been a factor, the captains of the warships could not be absolved of their responsibility for safe navigation.