India's Mazagon Dock Shipbuilders Limited (MDL) has launched the fourth of six Kalvari (Scorpène)-class diesel-electric attack submarines (SSKs) being licence-built for the Indian Navy (IN).
The 67.6 m-long boat, which is named Vela , entered the water on 6 May at the Naval Dockyard in Mumbai and is expected to undergo "rigorous trials and tests" before being delivered to the IN by 2020.
The submarine, which is part of the IN's INR235.62 billion (USD3.39 billion) Project 75 programme, follows INS Kalvari , which was commissioned in December 2017, and Khanderi and Karanj , both of which are slated to enter service later this year.
The fifth and sixth submarines - Vagir and Vagsheer - are in advanced stages of construction on MDL's assembly line, and are likely to be launched in 2020-21. All six Kalvari-class boats are expected to be in service by 2022, IN sources said.
Each submarine of the class displaces 1,615 tonnes when surfaced and 1,775 tonnes when submerged and is expected to incorporate advanced acoustic quieting systems to ensure stealth. The SSKs are capable of carrying out anti-surface and anti-submarine warfare, intelligence gathering, mine-laying, and surveillance.
Like the three previous boats of the class, Vela will be equipped with Exocet SM39 sea-skimming anti-ship missiles, C303/S anti-torpedo countermeasure systems, and German-built SUT-series torpedoes, the latter of which will eventually be replaced with heavyweight torpedoes.
The IN's Kalvari-class boats were initially configured to receive Black Shark heavyweight torpedoes from Italy's Whitehead Alenia Sistemi Subacquei, but the deal to acquire 98 of these was terminated in May 2016 following corruption allegations.
Official sources said the response from at least one overseas heavyweight torpedo manufacturer is currently under IN consideration.
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