In December of 2017, INS Kalvari (S50) became the latest addition to the Indian Navy undersea fleet. Its design is based in the French Scorpene-class (by DCNS of France) which also makes up new boats added to the inventories of Brazil, Chile and Malaysia. INS Kalvari is the lead ship of a planned six boats making up the Kalvari-class for the Indian navy service. She was laid down by shipbuilder Mazagon Dock Limited of Mumbai on April 1st, 2009 and launched on April 6th, 2015. Her hull was completed on October 30th, 2015 and the boat was delivered to the Indian Navy in September 2016.
Her formal commissioning took place on December 14th, 2017, nearly a decade after her keel was laid down. The name "Kalvari" translates to "Tiger Shark" and follows the first Indian submarine taken into service (since decommissioned), the INS Kalvari of December 8th, 1967. The new boat was built under the "Project 75" initiative to help bring more indigenous military building programs to India.
INS Kalvari (S23) displaces 1,725 tons and has a length of 202 feet with a beam of 20 feet and a true draught of 19 feet. Her power comes from a conventional diesel-electric arrangement requiring her to surface to recharge her battery pack. Surfaced speeds can reach 12 knots and submerged speeds peak at 20 knots. Range is out to 7,500 miles and the boat can stay at sea for up to fifty days with its modest crew of thirty-one. The high-stress hull has been tested to depths of 350 meters. As with other modern submarine types, much attention has been paid to making the Kalvari a quiet underwater vessel and thus her acoustic signature is reportedly low (and makes her highly useful in the intelligence-gathering role).
Aboard is a typical armament fit comprised of 6 x 533mm (21") torpedo tubes with eighteen torpedo reloads. These fire the "Black Shark" or "Varunastra" torpedo families but are also capable of launching the French-made SM.39 "Exocet" anti-ship missile. The boat can be used in the ocean-space denial role as a minelayer when outfitted to carry 30 naval mines (in lieu of torpedoes) for such missions. The torpedo tubes are all bow-mounted / bow-facing.
Externally, the boat has a traditional design arrangement with a rounded bow, tapered stern and mid-set sail. The drive planes are located at the sail and the tailplanes are of a cruciform arrangement.
INS Kalvari marks the first of the French Scorpene-class submarines to be delivered to the Indian Navy and represents a boost to the nation's underwater force - though the country still trails regional adversary China.