The Delhi Class design, for which Russia's Severnoye Design Bureau (SDB) acted as a consultant, are hybrids of Western and Russian technology - incorporating elements of the Sovremenny Class destroyer and the Rajput Class (Kashin-II) destroyer with the locally-designed Godavari Class frigate, including the frigate's most unique aspect, namely the large dual helicopter hangar for two Sea King Mk.42B helicopters. The huge missile blast deflectors on INS Delhi indicate an original intention to fit the supersonic 3M-80 (NATO: SS-N-22 Sunburn) AShM which was deemed too costly. INS Mysore and INS Mumbai lack these blast deflectors.
Weapons: Sixteen 3M-24E (Kh-35 Uran or NATO: SS-N-25 Switchblade) AShMs, housed in four quadruple KT-184 launchers, angled at 30, two on either side of the bridge superstructure. Equivalent to the Harpoon Block 1C AShM, these missiles have active radar homing (ARH) out to a range of 130 km at 0.9 Mach, with a 145 kg warhead. All 16 missiles can be ripple-fired in 2-3 second intervals. The Delhi Class will be retrofitted with the GLONASS-steered, land-attack 3M24E1 Uranium AShM at a later date. The 3M24E1 AShM - export variant of the 3M24M1 - has more fuel, which extends range to 250 km.
Fire control for the missiles, is provided by a Garpun-Bal FC (NATO: Plank Shave) radar, mounted atop the bridge. This radar combines active and passive channels and in the active target designation mode, it operates in X-band (I/J-band) and can handle up to 150 targets at ranges between 35 - 45 km, although it is possible to obtain ranges of more than 180 km in wave-guide propagation conditions. The passive channel operates in the ESM mode searching for pulse and CW signals, and accurately identifying the bearing of hostile emitters from a built-in classification library of up to 1000 signatures. The maximum range of the passive channel is over 100 km depending on the frequency.
In the air defence role, a pair of 3S-90 launchers - one installed forward of the bridge and the other atop the dual helicopter hangar - are fitted with the Shtil SAM system. The Shtil system comprises of the 9M38M1 (SA-N-7, navalised SA-11) missile and 24 such missiles are carried in a below-decks magazine. The launchers elevate up to 70 but have a limited firing arc of 30 within the centreline. The launcher groups require a crew of 20 men and weigh about 50 tons. Target tracking data is provided by the MR-775 Fregat MAE planar array radar which can engage up to 12 targets at ranges of 32 km. Target illumination and semi-active homing is provided via six MR-90 Orekh (NATO: Front Dome) illuminators, four mounted forward and two aft.
The 9M38M1 SAM, designated as Kashmir by the Indian Navy, is armed with a 70 kg high-explosive warhead, has a maximum speed of Mach 3 (830 m/s) and can manoeuvre up to 20 g. The missile can handle target aircrafts traveling at 420 to 830 m/s and incoming missiles moving at 330 to 830 m/s. The reaction time is 16 to 19 seconds and the advertised kill percentage is 81 to 96% for a two-missile salvo. Ranges against aircraft are 3 km to 32 km with altitudes from 15 metres to 15 km. Ranges against incoming missiles are 3.5 km to 12 km with altitudes from 10 metres to 10 km. The missile probably has a secondary anti-ship capability.
INS Delhi has been fitted with the Barak SAM system and it appears that the pair of MR-123-02 (NATO: Bass Tilt) directors have been replaced by two EL/M-2221 directors, in addition to deckhouse modifications. It is unclear if the 30mm AK-630 Gatling guns aboard INS Delhi have been removed to place two revolver launchers for the Barak SAM system or if the Barak's VLS tubes are beside the mast.
One 100mm AK-100 single-barrelled, water-cooled gun, for use against ship and shore targets. The AK-100 can engage aerial and surface targets at a rate of fire of 30 to 50 rds/min and the turret can traverse through an arc of 220. Fire control for the gun is provided by the T91E radar, a part of the MR-145 or MR-184 (NATO: Kite Screech) fire control radar system along with a turret mounted Kondensor optical sight. Each shell weighs 16 kg.
