Talwar-class frigate

Batch-I

On 17 November 1997, Russia and India signed a $1 billion contract, for three Krivak III-class multi-purpose frigates. The Indian Navy wanted to fill the gap created by the decommissioning of the Leander-class frigates until the Project 17-class frigates entered service.

After the signing of the contract, Severnoye Design Bureau began a detail design layout and the shipbuilder, Baltisky Zavod of St. Petersburg, began preparations for their construction. The project involved around 130 suppliers from Russia, India, Britain, Germany, Denmark, Belarus, Ukraine and other countries including over 30 St. Petersburg-based naval design organizations and institutes.

The first frigate, INS Talwar was delivered in May 2002. The second, INS Trishul, was delivered in November 2002 and the third, INS Tabar, in May 2003. The Russian firm delayed the delivery of three frigates by 13 months, 7 months and 11 months respectively. The contract stipulated the levy of liquidated damages for the delays and the same worked out to the equivalent of US$38.5 million. This was yet to be recovered as of December 2005.

Batch-II

The Government of India signed a follow-on contract for the purchase of three additional frigates on 14 July 2006. These ships will be built at Yantar Shipyard in Kaliningrad. The first frigate was scheduled for delivery in April 2011. These ships will feature BrahMos supersonic anti-ship cruise missile instead of the Klub-N/3M54TE missile system which was provided to the Talwar, Trishul and Tabar frigates.

Batch-III

In July 2012, India Today reported the start of talks about purchasing three additional Talwar-class frigates (No.7 to No.9).^[9] In March 2016, it was reported that India and Russia are still negotiating the purchase of the additional ships.^[10][11]

In September 2016, it was reported that India would acquire two Admiral Grigorovich-class frigates from Russia and remaining two will be built in India.^[12] These frigates are based on the Talwar class and were to be commissioned into the Russian Navy, but after the Ukrainian Conflict, Ukraine refused to supply any more engines for the Russian ships. As of then, only two of the six have been commissioned by Russia.^[13] In August 2017, the Indian Defence Acquisition Council (DAC) cleared a proposal of ₹490 crore (equivalent to ₹687 crore or US$82 million in 2023) to buy two gas turbines from Zorya-Mashproekt in Ukraine for the Admiral Grigorovich-class frigates being built in Russia.^[14][15] Each M7N1 system includes two DT59 top speed (boost) gas turbines, two DS71 cruise turbines, two R063, one R1063 reduction gears and its control system. It can provide a total power output of 44,000 hp (33,000 kW). The powerplants were delivered to Kaliningrad Shipyard in late 2020 to early 2021.^[16]

In October 2018, Indian Ministry of Defence signed a deal for ₹8,000 crore (equivalent to ₹110 billion or US$1.3 billion in 2023) for procuring two Admiral Grigorovich-class frigates, Admiral Butakov (renamed INS Tushil) and Admiral Istomin (renamed INS Tamala).^{[17][18][19][20]} The two frigates was scheduled to be delivered to Indian Navy by 2022.^[21][22] The last frigate, the former Admiral Kornilov, is to be sold abroad. (Total: 3 ships built for the Russian Navy, 3 ships under construction for sale abroad).^[23]

On 11 March 2024, reports emerged that INS Tushil, being built by Yantar Shipyard has started sea trials. The initial Pennant number is 435.^[7][24] In April 2024, a report suggested that INS Tushil will be delivered to India in September 2024 whereas INS Tamala will be handed over in February 2025. The timeline is on track as of July 2024.^[25][26][27] As of July 2024, to conduct acceptance trials for the two frigates being built in Yantar shipyard, a team of around 200 personnel of the Indian Navy are in Russia.^[28]

It was reported in September 2024 that INS Tushil is to be commissioned by 2024-end.^[29] As of 11 November 2024, INS Tushil is to be delivered to India by the end of the month. The frigate is to be handed over to the Indian crew of over 200 officers and sailors at Kaliningrad Shipyard. The ship will later be commissioned by Indian Defence Minister Rajnath Singh in early December 2024 during a formal visit to Russia. The latter INS Tamal is to be delivered in early 2025.^[20]

INS Tushil was commissioned on 9 December 2024 by Rajnath Singh.^[8]

Batch-IV

A contract, worth ₹13,000 crore (equivalent to ₹170 billion or US$2.1 billion in 2023), was signed between Rosoboronexport and Goa Shipyard for the construction of 2 frigates under license on 20 November 2018. The two frigates will be armed with BrahMos missile system and will include a host of Indian equipment and will be delivered by 2027.^[19][20] The contract for the two ships was awarded to Goa Shipyard Limited by the Government of India on 30 January 2019.^[30] The two frigates being built at Goa Shipyard will boast much higher indigenous content and will be named Triput class frigate. The new class of ship will feature BHEL-manufactured OTO Melara 76 mm gun instead of its Russian counterpart, along with other Indian weapon and sensors.^[31]

In September 2021, India ordered two sets of modified M7N2E units for Batch-4 frigates at the coast of $100 million which has upgrades like microprocessor control system and a power output of 58,000 hp (43,000 kW), higher than previous subclasses. The powerplants are scheduled to be delivered by December 2022 and July 2023, respectively.^[32][16]

On 23 July 2024, INS Triput was launched by GSL shipyard.^[33] As of then, the delivery of INS Triput is expected in 2026 and the next ship shall be delivered after 6 months of the former.^[25][26]

Power plant

The Talwars features the Zorya designed and Mashproekt (Ukraine) manufactured M7N.1E gas turbine plant which comprises two DS-71 cruise turbines and two DT-59 boost turbines in two engine rooms. The cruising component consists of two DS-71 gas-turbine engines, each rated at 9,000 horsepower (6,700 kW) in forward running, and 1,500 hp (1,100 kW) in reverse. Two cruising RO63 two-speed gearboxes and one cruising R1063 auxiliary gearbox which makes it possible to use any of the cruising engines to drive both propeller shafts. A boost component with two DT-59.1 gas-turbine engines, each rated at 19,500 hp (14,500 kW) forward running, 4,500 hp (3,400 kW) in reverse and two RO58 single-speed reduction gearboxes. The four gas turbines are mounted on isolated cradles which minimize their contact with the hull and thereby considerably reduce the transmission of her vibration and sound.^[4][34]

Electrical power is provided by four 1 MW Wärtsilä WCM-1000 generator sets with Cummins KTA50G3 engines and Kirloskar 1 MV AC generators. The contract for the generators was signed with Wärtsilä Denmark.

Flight deck

The Talwar class can accommodate one Ka-28 Helix-A antisubmarine helicopter or one Ka-31 Helix-B airborne early warning helicopter which can provide over-the-horizon targeting. The vessel can also embark the navalised variant of the indigenous HAL Dhruv.

Primary weapon

In the main strike role, an eight-cell 3S14E vertical missile launcher is fitted, which accommodates the 3M-54E Klub-N anti-ship missile developed by the Novator Design Bureau. The Agat Research and Production Enterprise has supplied the 3R14N-11356 shipborne fire-control system associated with the Klub-N. The 3M-54E Klub is an 8.22 metres (27.0 ft) long missile using active radar guidance with a range of 220 kilometres (140 mi). It is a three-stage missile in which the terminal stage reaches supersonic velocity (Mach 2.9) when it is approximately 20 km (12 mi) from its target.^[35]

The later batches of 7 ships (Teg onwards) are fitted with the BrahMos supersonic cruise missile, which has a range of 300 kilometres (190 mi) and moves with the velocity of Mach 3 throughout its flight.^[36][37][38]

Air defence

The Shtil-1 SAM system with a 3S-90 missile launcher is fitted forward of the bridge and is armed with the 9M317 (SA-N-12 "Grizzly", navalised SA-17) missile. 24 missiles are carried in a magazine located below deck. Guidance and target illumination for these missiles is provided by four MR-90 Orekh (NATO: Front Dome) radars, which are connected to a command and control post. The SA-N-12 missile uses a combination of inertial guidance and semi-active radar homing to its maximum range of 45 km (28 mi). The 70 kg (150 lb) blast-fragmentation warhead is triggered by a radar proximity fuze. The missile's control system and warhead can be adjusted to a specific target following target recognition, which increases hit probability. Eight Igla-1E (SA-16) portable air defence missiles are also carried.

Main gun

One 100 mm A-190E gun is fitted forward for use against ship and shore based targets The A-190(E) uses a lightweight gun mount with an automatic gun and fuze setter. Fire control is provided by the 5P-10E Puma FCS. The gun can fire 60 rounds a minute out to a range of 8.2 nautical miles (15.2 km). The weight of each shell is 16 kilograms (35 lb).

INS Trishul had her 100mm gun replaced by a OTO Melara 76 mm SRGM (Super Rapid Gun Mount) naval gun after her refit. The other ships of the class may be similarly modified.

The gun features higher automation of fire preparation and control and employs advanced guided and rocket-assisted long-range and enhanced-lethality projectiles fitted with dual-mode impact/proximity fuzes. Together with the use of the muzzle velocity meter, it is designed to produce increased combat capability. In addition, the gun turret features stealth technology to minimize the radar signature of a ship.

Anti-submarine warfare

The ships carry the RPK-8 system, which uses a 12-barrelled RBU-6000 ASW rocket launcher^[40] to fire the 212 mm 90R anti-submarine rocket or RGB-60 depth charges. The firing range is from 600 to 4,300 metres (2,000 to 14,100 ft), and the depth of engagement is up to 1,000 metres (3,300 ft).

Two twin 533 mm DTA-53-11356 fixed torpedo tube launchers are fitted amidships and fire the SET-65E/53-65KE torpedoes. The Purga anti-submarine fire-control system provides control for both the RBU-6000 and DTA-53 launchers.

Radar

• Surface search: One 3Ts-25E Garpun-B radar at I-band frequency, using both active and passive channels, provides long-range surface target designation. One MR-212/201-1 radar at I-band frequency is used for navigation and a separate Kelvin Hughes Nucleus-2 6000A radar set is used for short-range navigation and surface surveillance. Also fitted with a Ladoga-ME-11356 inertial navigation and stabilisation suite supplied by Elektropribor.
• Air/surface search: One Fregat M2EM (NATO: Top Plate) 3D circular scan radar at E-band frequency, provides target indication to the Shtil-1 missile system. Featuring continuous electronically scanned arrays, the radar rotates at 12 or 6 rpm and has an instrumented range to 300 km.
• Fire control: Features a Ratep JSC 5P-10E Puma fire control system, consisting of a phased array and target tracking radar along with laser and TV devices. The system, fitted above the bridge deck, features in-flight course correction updates via data links, has a maximum detection range of 60 km, operates autonomously and is capable of automatically locking on to four targets and tracking them.

Sonar

According to some reports, the APSOH (Advanced Panoramic Sonar Hull) hull-mounted sonar is fitted on the vessels. The APSOH sonar performs active ranging, passive listening, auto tracking of targets and classification. Other reports indicate that the BEL HUMSA (Hull Mounted Sonar Array) sonar is fitted. The HUMSA is a panoramic medium-range active/passive sonar system developed by the Naval Physical and Oceanographic Laboratory (NPOL).^[6]

Information released from the Severnoye Design Bureau (SDB) indicate that French towed array sonars (TAS) are also fitted. This is very plausible given that many Indian Navy ships now use French TAS, however INS Talwar shows no signs of such a system. The vessel may also have a Russian SSN-137 Variable Depth Sonar (VDS) with NATO reporting name Steer Hide, providing active search with medium frequency, and the sonar might be license produced in India with Indian designation SSSN-113.^[41]

Countermeasures

The frigate features the Russian-made TK-25E-5 integrated electronic warfare suite, which comprises a wideband electronic support measures system that has antenna arrays mounted in the superstructure and a multimode jammer. Four KT-216 decoy launchers, forming part of the PK-10 system, are fitted for soft-kill defence. A total of 120 120mm chaff and infrared decoy rounds are carried on board.

Some ships of the class including INS Tabar have had their TK-25E-5 ESM suites replaced with BEL manufactured Varuna ESM systems with their distinctive circular housing located above the Fregat radar.

Combat data system

• The Trebovaniye-M combat information and control platform is a fully distributed combat management system. It controls all platforms of attack and defence weapons, independently generates combat missions based on situation analysis, determines optimal number of missile firings, displays information on the state of ship-borne weaponry and transmits data to protection systems.
• Interconnected via an Ethernet LAN, Trebovaniye-M features eight T-171 full-colour operator workstations (with 18-inch colour flat panel displays) and three central T-162 servers. Individual items of combat system equipment interface to Trebovaniye-M via T-119 and T-190 bus interface units. Raw radar data is received through a T-181 data reception unit.