Nilgiri (Leander) Class

Image © Mrityunjoy MazumdarImage © Mrityunjoy MazumdarImage © Mrityunjoy MazumdarINS Udaygiri at sea. Image © Indian NavyA top view of INS Udaygiri. Image © Indian NavyINS Dunagiri patrolling the waters. Image © Indian NavyThe Nilgiri in rough waters. The picture is dated as she was decommissioned in 1996. Image © Indian Navy

Vessel Type: Frigate.

Names & Pennant Numbers with commission dates:

INS Taragiri F41 (16 May 1980)
INS Vindhyagiri F42 (08 July 1981)

Names & Pennant Numbers with commission dates:
Nilgiri F33 (23 June 1972) - decommissioned in 1996

Himgiri F34 (23 November 1974) - decommissioned on 06 May 2005

INS Udaygiri F35 (18 February 1976) - decommissioned on 24 Aug 2007

INS Dunagiri F36 (05 May 1977) - decommissioned on 20 Oct 2010

Structure: Similar design to the Broad-beam Leander Class frigates, but with several differences. The first two vessels, the hangar was provided with telescopic extension to take the HAL Chetak helicopter. The last two vessels (F41, F42) have had a design change, with aircraft space increased to make way for a Sea King Mk.42 with a telescopic hangar and Canadian Beartrap haul down gear. In these two, an open deck has been left below the flight deck for handling mooring gear and there is a cut-down to the stern.

Displacement: 2682 tons standard.
...................2962 tons full load.
*F42 lists at 3039 tons full load.

Dimensions: Length - 113.38 metres.
.................Beam - 13.1 metres.
.................Draught - 4.27 metres.

Main Machinery: Two 550 psi boilers, two 30,000 hp motors and two shafts.

Maximum Speed: 27 knots for the first three ships.
.......................24 to 28 knots for the last two ships.

Maximum Range: 4000 miles at 12 knots.

Complement: 267 (incl. 17 officers).
..................300 (incl. 20 officers on F41)

Radar: Air; One Signaal DA05 / BEL PFN513 radar, at E/F-band frequency for medium-range surveillance and target indication to weapon control systems. Mounted atop the foremast.
Surface; One Signaal LW08 / BEL RAWL02 radar at D-band frequency atop the mainmast.
.........Navigation; One Signaal ZW06 / BEL RASHMI radar at I-band frequency.
.........................One Signaal M-45 radar at I/J-band frequency.
.........................One Decca 1226 radar at I-band frequency.
IFF; Type 944, 954M.

Sonar: One Westinghouse SQS-505 / Graesby 750 hull mounted sonar, which provides active search & attack with medium frequency. One Type 162M bottom classification sonar at high frequency. Also has a Type 170 sonar which provides active attack with high frequency. The Westinghouse VDS is fitted in the first four vessels (F33 - F36) and provides active attack with medium frequency. The Thomson Sintra VDS is fitted in the last two (F41 - F42). The Himgiri was used as a trials ship for the indigenous APSOH (Advanced Panoramic Sonar Hull) sonar.

Helicopter Capacity: One HAL Chetak MATCH (Medium range Antisubmarine Torpedo Carrying Helicopter) on F33 - F36. One Sea King Mk.42 or one HAL Chetak MATCH on F41 and F42.

Weapons: Two Mk.6 Vickers 114mm guns with 80º elevation and 20 rds/min to 3.3n miles; 6 km against aircraft or 10.4n miles; 19 km against vessels. Also has four AK-230 30mm guns with 500 rds/min to 2.7n miles; 5 km in all but one of the class. Two Oerlikon 20mm guns with 800 rds/min to 2 km.

Six 324mm ILAS 3 (2 triple) torpedo tubes (F41 - F42) with Whitehead A244S or the Indian NST-58 anti-submarine active/passive homing torpedo, which has a range of 3.8n miles; 7 km at 33 knots with a 34 kg shaped charge warhead. One Bofors 375mm twin-tubed launcher (F41 - F42) which have a range of 1600 meters. One Limbo MK.10 triple-tubed launcher (F33 - F36) which have a range of 1000 miles with a 92 kg warhead.

Countermeasures: ECM; The Racal Cutlass system is used as an ECM jammer.
.........................Decoys; The
Graesby G738 system is used as a towed torpedo decoy.
.........................ESM; Bharat Ajanta; intercept in F34, F36 and F42. FH5 Telegon D/F in some.

Comments: Leander Class frigates served as the mainstay & workhorse of the Indian Navy and they currently form the 14th Frigate Squadron. The last two vessels (F41, F42) have more powerful engines than the remainder. INS Taragiri had a serious fire in July 1994, but was repaired and was back in active service in 1995. Westinghouse has supplied the Indian Navy with ASW sonar systems, two hull mounted arrays and three visible depth sonar arrays which are installed inside towed bodies built by Fathom Ocean Ltd. Transducer elements in both cases are identical. INS Udaygiri underwent a refit at Naval Dockyard, Mumbai. The remaining vessels in the series were expected to have their armaments brought into line with later ships. It has not been reliably confirmed through official channels, whether this has actually occurred.

The Nilgiri was decommissioned in 1996 after 24 years of service. She was sunk on 24 April 1997, by a Sea Eagle AShM fired from a Sea Harrier Frs Mk.51 of the Indian Naval Air Arm. The Himgiri was decommissioned after 30 years of service on 06 May 2005. The vessel holds the distinction of having the maximum number of days at sea in single commission and was the first to shoot down a pilotless aircraft in 1976. Captain K N Zadu, VrC, (Retd.) who served as her first commanding officer, was the chief guest at the decommissioning ceremony along with Commander Ravneet Singh who served as her last commanding officer. INS Dunagiri is named after one of the Himalayan peaks. It's crest depicts the Osprey, a Himalayan bird and the ship's motto is 'Victory Is My Profession'. INS Taragiri is named after a hill range in Garhwal Himalayas in Northern India.