New Delhi, July 3: Two submarines of the Indian Navy’s fast-depleting fleet collided while one was berthing next to the other at a jetty in the naval dockyard in Mumbai but defence sources insisted the damage was minor.

The incident, which happened on June 19, was enough to worry the naval headquarters — though accidents involving submarines are not all that rare — because the Indian Navy’s “silent arm” is making do with ageing vessels that will be scrapped before newer ones can be commissioned.

A defence official said the damage was “little more than dents in the hull”. One of the submarines has already been repaired.

No one was injured.

Parallel berthing is routine because the dockyard does not have enough jetties for all vessels.

“It is a minor incident. A routine inquiry is being conducted. But such things keep happening,” a naval officer said.

In January 2008, the Indian Navy’s Russian-origin Kilo class submarine, the INS Sindhughosh, collided with a merchant vessel during exercises off the coast of Gujarat.

The submarine was just below periscope depth in shallow waters and was surfacing when its periscope, and probably also the conning tower, hit the bottom of the merchant ship.

The submarine returned to Mumbai on its own but the damage was serious, though the vessel has been repaired and is back in service.

The Indian Navy has 15 submarines in its fleet, of which 10 are kilo class bought from Russia, four are German-origin HDW and the other is an old Foxtrot.

A second Foxtrot is to be de-commissioned this month.

The navy’s plan to get six Scorpene submarines through a contract with DCN Thales has been disrupted.

With the time slippage, the navy does not expect the first of the Scorpenes to be commissioned before 2015, by when at least three other submarines will be due for de-commissioning.

The accident in Mumbai does not compare with the fright that the British and French navies gave the world last year when their nuclear-powered, nuclear-missile-carrying submarines, the HMS Vanguard and the Le Triomphant, collided in the Atlantic off France in February last year.

Both the navies claimed that the damage was not serious and that there was no risk of radiation. The submarines collided apparently because the technology used to detect other submarines failed.