Navy is investigating into the cause which led to a minor crack in the sonar dome of its frigate INS Betwa earlier this month. The crack was detected during routine operational and maintenance check when the ship was docked at Mumbai harbour after the warship returned from deployment in deep sea.
Giving details here on Wednesday, officials said the protective cover of the sonar dome located at the bottom of the ship to detect submarines had developed a hairline crack.
Maintenance check found that the cover filled with fresh water had turned saline, they said adding the dome is of one to one and half metre in radius and is made of special steel.
The ship was then taken to dry dock for checks and investigations were on to find out the cause of fresh water turning saline. Officials said the crack could have developed due to material failure or a foreign object crashed against the dome. They also said routine checks are carried out to ascertain the salinity of the water in the dome.
Incidentally, this is the fifth case where warships suffered damage in the last few months. Submarine INS Sindhurakshak sank in Mumbai harbour in August last year following explosions killing all 18 personnel on board.
A few months later a new warship caught fire while it was stationed at the Vishakhapatnam. Aircraft carrier INS Virat also saw a minor fire most probably caused due to short circuit in the ship's air conditioning system.
A fishing trawler recently sank after colliding with frigate INS Talwar near Ratnagiri district of Maharashtra injuring four fishermen on board.