The hard journey of the "Cassin" class in South Asia

The "Kasin" class developed by the Soviet Union began to be designed in 1956 and began to be built in 1962, the first large anti-submarine submarine designed by the Soviet Union to counter the United States nuclear submarines, the world's first surface combat ship using gas turbine engines, and the world's first surface ship with a helicopter magazine and flight deck at the beginning of the design. The Soviet Union began building the Type-61 Cassin class in 1962, completing a total of 26 ships; at first, the Cassin class was not equipped with anti-ship missiles. At the end of 1973, the last Soviet Kahin class entered service, which had a modified anti-air search radar and was equipped with an AK-230 30mm close-in gun and four P-15M (SS-N-2C) anti-ship missiles to enhance anti-air and sea self-defense capabilities; this improved Cassin class was called type-61M, and the Soviet Union subsequently improved five other Cassin-class ships with the same modification, called Type-61MP;

In 1974, India purchased the Type-61M guided-missile destroyer from the Soviet Union with the consent of the Soviet Union: the Soviet Nikolayev plant began to build five such improved versions of the Cassin class for India in the late 1970s, and made several modifications to India's needs, which India called the Rajput class, which was also the last five built in the Cassin class series. The five Rajput class are named with the word "R", and they entered service from 1980 to 1988. The ship has two pairs of chimneys, the first pair of chimneys is located between the two masts, and the second chimney is located behind the ship's stern, each pair of chimneys is tilted to the left and right sides. Compared with the steam turbine propulsion system, the gas turbine not only accelerates quickly, does not require hot standby, saves manpower and reduces noise, but also has a 15% reduction in displacement than the ships of the same class using steam turbines, showing the unique vision of the Soviet Union. The ship of this class is roughly the same as the late version of the Soviet Kasin class destroyer;

From 1993 to 1994, the ships were equipped with a new electronic warfare system and an IPN-10 combat system from Selenia, Italy. In the early 2000s, one or two of the last two ships of the class (D-54 and 55) were modified to install Israeli-made radar, fire control and missile systems: Elta's EL/M-2238 STAR multibeam search radar and the Barak-1 anti-aircraft missile system, replacing the original MR-123 with two EL/M-2221 STGR irradiation radars. In addition, at least three ships of this class are said to be refitted with HUMSA Mk1 bow active/passive sonar developed by Doro and manufactured by BEL in India during the modification;

On each side of the naval gun fire control radar in front of the bridge is a 12-piece RBU-6000 anti-submarine rocket launcher with a range of 6000m, a maximum attack depth of about 500m, and a warhead weight of 31kg. On each side of the bow base are two longitudinal P-20M (NATO code name SS-N-2D) anti-ship missile launchers, using active radar or infrared mapfinders (Mod2 type), with a range of 83 km, a speed of Mach 0.9, and a warhead weight of 513 kg. Two 30mm close-in air defense cannons were each equipped on each side of the tail stern, of which the first two ships of the class (D-51 and 52) used AK-230 twin 30mm cannons with a rate of fire of 500 rounds per minute, a range of 5 km, and a maximum elevation angle of 85 degrees; the last three ships of the class (D-53~55) were replaced by AK-630 30mm guns, using a six-barrel rotating gun body, with a rate of fire of 3,000 rounds per minute and a maximum elevation angle of 85 degrees; the rajput class bow had a Russian-made twin 76mm naval gun with a rate of fire of 90 rounds per minute , range 15km. There is a single-arm rotary anti-aircraft missile launcher on the platform behind the gun and behind the second pair of chimneys, each capable of loading 22 SA-N-1 Volna anti-aircraft missiles. SA-N-1 uses radar command and guidance, with a range of 31.5km, a maximum shooting height of 22860m, a flight speed of more than Mach 2, and a warhead weight of 60kg; since 2007, India has refitted four PJ-10 "Brahmos" supersonic anti-ship missile tilt launchers for the "Rajput" class destroyers, of which the D55 Ranvijay is equipped with the "Brahmos" vertical launcher; later, India purchased a Barak-8 from Israel to install on the Cassin class;

There is a flight deck at the stern that can accommodate a Russian-made Ka-28 coaxial reversed bi-rotor anti-submarine helicopter, or a French-licensed Indian-produced Skylark III light helicopter, known in India as HAL Chetak. The purpose of using a telescopic hangar is to save space, it shrinks the area of the flight deck to a minimum; after the hangar is extended upwards and the helicopter is pushed to the aft flight deck, it retracts downward again, making enough space for the main rotor of the helicopter to operate - the take-off and landing efficiency is very low, can not meet the contemporary anti-submarine/early warning/search/attack and other tactical needs; however, India does not have the technical ability to improve them, and the later version of China's brigade-class destroyers began to modify fixed hangars to prepare for large and medium-sized helicopters to ship, At the same time, many new methods of warfare were also practiced. To this day, the level of destroyer-based helicopter combat between the two countries is clear;

After the entry into service of the five Cassin-class ships, the Indian Navy acquired the aircraft carrier formation's long-range combat capability in ocean-going air defense: at that time, the Chinese Navy only had the brigade class to compete with it - the formation was far behind the Indian Navy in terms of medium-range air defense capabilities; however, due to India's severe lack of medium- and large destroyers and the construction cycle of new ships, the Cassin class has been overused - on May 6, 2019, the D53 hull 3 "INS Ranjit" retired after 36 years of service The first ship, the D51, was decommissioned in May 2021: this shows how scarce destroyers the Indian Navy is!

Originally, the Cassin class could have played a reference role in the development of destroyers in the Indian Navy: starting from the enlarged version of the Delhi class, Indian destroyers have imitated the style of the Kasin class weapons and induction systems to pile up the deck - only in this way can we bring a sense of security, in fact, it can be seen that the overall design/system integration capabilities of Indian warships are seriously insufficient; the role of borrowing has played a negative effect: India needs to find the ship design bureaus of Russia, France, and Italy to help, and the money that should be given cannot be less;

The Kasin class does not affect the efficiency of Indian shipbuilding in the slightest: in the past 30 years, India has built a total of 3 P15 "Delhi" class and 3 P15A "Kolkata" class destroyers - the Lamor Kasin class died of overwork in minutes!

Therefore, the remaining three ships of the Cassin class can only fill the gap in the destroyers of the Indian Navy, and how much they can still play depends on the energy of the Indian media.