INS Kolkata

The commissioning of Kolkata was delayed from 2010 to 2014 due to delays in her construction and technical problems which were found during her sea trials. The issue detected was the generation of additional noise, which occurred when the engine, gearbox and shaft were operated together, but which worked issue-free when run independently. The issues were fixed and the sea trials were completed by February 2014, when the ship returned to MDL to undergo minor work before delivery.[13][14][15]

On 7 March 2014, during a complete check-up of the ship's machinery to fix the problems found during sea trials,[13] a naval officer was killed and several workers were injured when a valve on a CO₂ bottle malfunctioned during a test of the vessel's carbon dioxide fire-fighting unit at the Mazagaon dockyard. For the test, fire-retarding carbon dioxide gas was to be released into a compartment; the test was part of the destroyer's delivery trials. Kolkata's engineering officer-designate, Commander Kuntal Wadhwa, inhaled a large amount of gas and was rushed to St George's Hospital, where he was pronounced dead. Two dockyard officials who also inhaled the gas were also taken to hospital for treatment.[16][17][18] MDL stated that the incident will not delay the scheduled commissioning of the ship.[13]

INS Kolkata firing a Long Range Surface to Air Missile

As part of her pre-commissioning weapon trials at sea, Kolkata test-fired a BrahMos missile off Karwar's coast on 9 June 2014, and the test met all parameters.[19][20] On 15 February 2015, a BrahMos missile was test fired from INS Kolkata during the Tropex exercise in the Arabian Sea.[21][22]

On 29 December 2015 and 30 December 2015 the Indian Navy successfully test-fired the Barak 8 missile from INS Kolkata.[23][24] Two missiles were fired at high speed targets, during naval exercises being undertaken in the Arabian Sea.[25][26]