Nilgiri-class frigate (2019)

Design

The Nilgiri-class (P-17A) was designed primarily using experience gained during the construction of the Shivalik-class frigates (P-17). The P-17A holds significant improvements over the P-17 class, in terms of weaponry and stealth.[36]

The vessels of the class integrate modern stealth features - including a low radar cross-section (RCS), and infrared signature reduction.[37] The vessels of this class, are also reported to have radar suppression screens and deck fittings, with little-to-no radar signature.[38] The design of the frigates are targeted at improving survivability, manoeuvrability and sea-keeping characteristics of the vessels.[37] The vessel's bow will also feature an enclosed mooring deck - which improves the vessel's stealthy profile, by contributing to the reduction of the vessel's RCS.[39]The frigates will also feature better roll stabilization and a discreet visual profile.[40]

The vessels will use high levels of automation, which will reduce the crew complement by approximately 60% - from the existing 257 (including 35 officers) to about 150; this in turn reduces the operational cost of the vessels by around 20% and helps in maintaining higher operational availability of the vessels.[37][41] The superstructure of the vessels, are reported to extensively utilize composite materials, similar to that of the Kamorta-class corvettes.[41] Furthermore, Italian shipbuilder Fincantieri was also contracted by GRSE - to provide technical advice and support for the vessels' construction.[42]

The anticipated cost for each vessel is above ₹4,000 crore (US$531 million) and the total deal is expected to be worth more than ₹45,000 crore (equivalent to ₹540 billion or US$7.1 billion in 2020).[43][44]

Weapon Systems

The vessels are equipped with a OTO Melara 76 mm naval gun. Originally, the Indian Navy had planned to install the Mk-45 127 mm naval gun, manufactured by BAE; however, this plan was reported to have been scrapped, on grounds of financial issues.[45] For point defence, the frigates are equipped with two AK-630M CIWS, present on both sides of the superstructure.[37]

The frigates are also equipped with 32 Barak-8ER surface-to-air-missiles (LR-SAM), and 8 BrahMos anti-ship missiles (AShM) (also used as land-attack missiles (LAM)), enclosed in VLS cells present at the bow.[37]

For anti-submarine warfare (ASW) capabilities, each frigate is equipped with two triple-torpedo tubes, presumably for launching the Varunastra heavyweight anti-submarine torpedo, developed the DRDO. The frigates are also equipped with two RBU-6000 anti-submarine rocket launchers, primarily for firing ASW rockets.[37]

The vessels' stern can accommodate two medium-sized helicopters, primarily the HAL Dhruv, or the Westland Sea King Mk. 42B, in a helicopter hangar.[37]

Sensors and Processing Systems

The P-17A frigates feature the IAI EL/M-2248 MF-STAR S-Band AESA radar - as its primary radar, for tracking both air and surface targets.[13] The P-17A frigates are also speculated to be equipped with the Indra LTR-25 'Lanza' radar - as its secondary radar - for tracking aerial targets, including ballistic missiles.[13] The frigates are also equipped with an advanced combat management system - CMS-17A, equipped with sophisticated data links for higher interoperability among other vessels.[46][47]

The frigates are also equipped BEL HUMSA-NG sonar, developed by the DRDO, for underwater detection/interception of hostile submarines.[48][47]

Electronic Warfare and Decoys

The frigates feature the "Shakthi" electronic-warfare (EW) suite - developed by the Defence Electronics Research Laboratory (DLRL), for defense against anti-ship missiles and for the interception, detection, classification, identification and jamming of conventional radars.[49] "Shakthi" is equipped with wide-band electronic-support measures (ESM), electronic countermeasures (ECM), an integrated "Radar Finger Printing System (RFPS)" and a data-recording replay feature for "post-mission analysis".[50][51]

As for the class' countermeasures abilities, each frigate possesses four Kavach anti-missile decoy systems (two present on either side of the superstructure),[52][22] and two NSTL Maareech torpedo-countermeasure systems.[22]

The Nilgiri-class is the first major class of Indian-designed warships to be built using integrated modular construction - a process in which a warship is built by first constructing smaller "modules" or "blocks", and then bringing them together for final assembly; this process helps in reducing the construction period of the vessels and the costs involved, and is also instrumental in integrating newer upgrades to the vessels.[53]

Four of the frigates are being built by Mazagon Dock Limited (MDL) in Mumbai and three by Garden Reach Shipbuilders & Engineers (GRSE) in Kolkata. The contract was signed with the two shipyards, in February 2015. According to official data, over 80% of the class' construction, will be done with Indian-made material and equipment, with more than 2000 firms involved in the construction process.[54] The steel-cutting ceremony for the first frigate - Nilgiri, was held on 17 February 2017, which marked the beginning of the class' construction.[55] Nilgiri is expected to be commissioned into the Indian Navy, by August 2022.[30][56]

On 11 March 2016, the Ministry of Defence (MoD) approved a ₹13,000 crore (US$1.7 billion) weapons and sensors package for the project. The frigates will be equipped with Barak-8ER surface-to-air missiles (LR-SAM), BrahMos anti-ship cruise missile, BEL Ajanta electronic warfare (EW) suite and the BEL HUMSA-NG sonar.[57][58]

In September 2018, MDL and GRSE awarded Bharat Electronics Limited (BEL) a USD $1.28 billion contract, to supply seven Barak-8 air-defence systems.[59][60] In October 2018, BEL signed a USD $777 million deal with Israel Aerospace Industries (IAI), for the supply of the seven systems.[61]

The first ship - Nilgiri, was launched by MDL in September 2019,[11][62] while the second frigate - Himgiri, was launched by GRSE, in December 2020.[63][64]

The first six ships of the class, were christened after their respective namesakes - the six ships of the older Nilgiri-class frigates (modified Indian variants of the Leander-class frigate) - Nilgiri, Himgiri, Taragiri, Udaygiri, Dunagiri, and Vindhyagiri.[33] The seventh and final vessel of the class, which did not have a namesake from the older class, was given the new name of Mahendragiri.[33]

The Indian Navy plans to have all seven P-17A frigates in active service by 2025-2027.[65][66]

• Future ships of the Indian Navy
• List of active Indian Navy ships

Frigates of comparable configurations and roles

• Shivalik-class frigate - a class of guided-missile frigates operated by the Indian Navy; the predecessor to the Nilgiri-class.
• FREMM multipurpose frigate - a family of multi-purpose frigates, operated by the navies of France, Italy, Morocco, Egypt and later, by the United States and Indonesia.
• Type 26 frigate - a class of frigates ordered by the navies of the United Kingdom, Canada and Australia.
• MKS 180 frigate - a planned class of frigates for Germany.
• Daegu-class frigate - a class of guided-missile frigates operated by South Korea.
• Mogami-class frigate - a class of multi-mission, stealth frigates operated by Japan.
• F110-class frigate - a planned class of multi-purpose frigates for Spain.
• Admiral Gorshkov-class frigate - a class of guided-missile frigates operated by Russia.

• Project 17A frigate at Bharat-rakshak.com