Mumbai, Jan 31 (IANS): The third indigenously-built diesel-electric Scorpene-class submarine, INS Karanj, was launched at the Mazagaon Dock Shipbuilders Ltd (MDL) here on Wednesday morning by Reena Lanba, wife of the Indian Navy chief, Admiral Sunil Lanba.

Another three Scorpenes being built by MDL in collaboration with DCNS of France under a Transfer-of-Technology contract, are in the pipeline.

The first of the vessels, INS Kalvari, was commissioned into the Indian Navy on December 14, 2017 while the second, INS Kandhari was launched in January of that year and is undergoing sea trials.

Speaking on the ocassion, Admiral Lanba said that the launch of INS Karanj marked a significant departure from the manning and training philosophy that was adopted for the first two submarines, adding that from the present vessel onwards, the Navy would be fully self-reliant in the training and certification processes.

The previous INS Karanj had served the nation for 34 years from 1969 to 2003 and had also participated in the 1971 war, he added.

The state-of-the-art technology utilised for constructing the Scorpene class submarines has ensured superior stealth features such as advanced acoustic silencing techniques, low radiated noise levels, hydro-dynamically optimised shape and the ability to launch a crippling attack on the enemy using precision guided weapons.

The attack can be launched with both torpedoes and tube launched anti-ship missiles, whilst underwater or on surface. The stealth of this potent platform is enhanced by the special attention given to various signatures. These stealth features give it an invulnerability, unmatched by most submarines.

A sophisticated and state-of-the-art Shore Integration Facility has been developed at MDL for integration and simulation of various equipment of the Scorpene submarine combat system for which there was no facility available in the country.

However, in a setback to the programme, the indigenous AIP will not be incorporated in vessels five and six as orignally planned but retrofitted on all six boats at a later stage.

Air Independent Propulsion (AIP), being developed by the Maharashtra-based Naval Materials Research Laboratory (NMRL), is a fuel cell that replaces diesel in the conventional submarines.

With this system, a conventional submarine that needs to surface every three to four days for oxygen, can stay under water for up to two weeks.