Anti-Ship Missiles: India and Pakistan

Columnist Syed Imran Shah discusses the acquirement/development of these missiles in South Asia.

Anti-ship missiles have come to play a pivotal role in deciding the outcome of a naval battle. Let’s take a look at the past. In 1971 war, Pakistan Navy suffered due to SS-N-2 Styx anti-ship missiles. The minesweeper PNS (Pakistan Naval Ship) Muhafiz and PNS Khyber were sunk by Styx anti-ship missiles fired from Missile Boats of Indian Navy.
In 1967, the Egyptian Navy used these Styx missiles to sink the Israeli destroyer Eliat.
In the Falklands War in 1982, Argentinean Exocet missiles hit three British ships and in Iran-Iraq war throughout the mid-1980s, Iraqi missiles sank at least five Iranian vessels. In May 1987, two AM-39 Exocets fired from an Iraqi Mirage severely damaged the USS Stark. All these conflicts show the awesome prowess of the modern anti-ship missiles, especially the air-launched ones. The unequivocal demonstration of the Exocet’s effectiveness made it a ubiquitous weapon system. Thus, it has been proved time and again that anti-ship missile is a potent maritime strike weapon. Due to the long-range advantage of the anti-ship missiles, they shall be more instrumental in sinking the ships than torpedoes in a naval war.
Club missiles, Kh-35 Uran, Sea Eagle and P-20 are the main anti-ship missiles (AShMs) of Indian Navy.
AM-39 and SM-39 Exocets, R/UGM-84 Harpoons, HY-1s and C-802s are the anti-ship missiles of Pakistan Navy.

Before discussing the anti-ship missiles, lets first discuss their target, the ship. In the Navies of the world, there are many types of warships like aircraft carriers, helicopter carriers, battleships, cruisers, destroyers, frigates, corvettes and missile boats. Aircraft carriers are the largest surface vessels that can accommodate up to 80-90 aircraft. Helicopter carrier is smaller than aircraft carrier. Battleship is a category that was at its peak in WW2. Large battleships like the Iowa class of USN, German Bismarck and Japanese Yamato had 16, 15 and 18-inch guns respectively. They are now obsolete, although USN Iowa class battleships are occasionally used to support shore landings of US Marine Corps. Cruiser is a class of traditional warship, second in size only to battleships; so called because they were built for high speed and long “cruising” distances.
Destroyer is a warship smaller than a cruiser but bigger than a frigate, able to operate independently or as an escort for larger naval vessels and convoys. Frigate is a warship usually smaller than the destroyer, capable of independent operations (or with others) in countering submarine, air and surface threats. Corvettes and missile boats are other smaller vessels.

Anti-Ship Missile Inventory
Before discussing the anti-ship missiles, lets first see the nomenclature of AShMs. The US nomenclature is AGM, UGM and RGM. AGM is used for air-launched, UGM for underwater or submarine-launched and RGM for ship-launched missiles. For Russian AShMs, SS-N-X stands for Surface-to-Surface-Naval. SA-N-X stands for Surface-to-Air-Naval. Furthermore, SSK is used for conventional submarine, SSN for nuclear submarine, and SSBN for ballistic missile carrying nuclear submarine. We now discuss the Indian AShMs.
The Kh-35 Uran has a maximum range of 130km and has active-radar terminal seeker. Ship-launched version is called SS-N-25. It carries 145kg HE (High Explosive) warhead. The terminal radar seeker locks on the ship from a distance of 15 to 20km. After missile lock-on, the missile descends to 2-5 metres over the sea surface for terminal phase of ship strike. India ordered 100 kh-35s in 1997.
Indian Delhi Class destroyers are equipped with 16 Kh-35 Uran anti-ship missiles in four quadruple launchers. Other sister ships are INS Mysore and INS Mumbai. Each of the three Godavri class frigates and three Krivak-3 class frigates carry 16 kh-35s. Khukri class corvettes also carry 12 kh-35 missiles each.
Pakistan Navy has acquired the SM-39 Exocets with its three Agosta-90B submarines from France. This is a very important capability for crippling the Indian warships.
In response to this acquisition, the IN has acquired the long range 3M54 Club AshMs from Russia. India was the first customer of these missiles. They have a maximum range of 220km. The maximum range of its radar seeker is 65km but is operated at 20km to target to minimize the warning to the target ship. The movement of its radar antenna is 45 degrees in both sides in azimuth. It has three stages of flight as compared to traditional two stages. In the first stage, a solid booster motor fires the missile and takes it to 150 metres altitude. At the end of boost phase, the inlet of turbojet engine opens and booster is jettisoned. Also two wings are deployed for long range and missile cruises at Mach 0.55-0.8. The turbojet powers the missile during mid-course. This mid-course can be programmed either at low-level or at altitude.
The missile receives its mid-course guidance from the GLONASS (Global Navigation Satellite System). This turbojet separates from the missile at a range of 60-20km from target, depending upon the operation of radar seeker. After the radar lock, turbojet separates and a solid rocket motor accelerates the missile to Mach 3 during the terminal phase at an altitude of 5-10 metres.
The three Krivak-3 class frigates (INS Talwar, Trishul and Tabar) of Indian Navy are fitted with eight ‘3M54E’ Club missiles per ship. These Club missiles are also fitted on the Kilo class submarines of IN. IN has ten Rubin Project 877EKM Kilo class submarines. These submarines were retrofitted with Club missiles in Russia. Each submarine is fitted with 6 Club missiles. China was the second customer of the Club missiles and installed these missiles on its Kilo class submarines.
Indian Navy also operates the British Sea Eagle AShM. The range of Sea Eagle is 93km and is carried by Jaguars, Sea Harriers and Sea King helicopters.
The Sea Eagle can be launched in fully computed mode with target data provided by aircraft or reversionary mode with no data from the launching aircraft. The Sea Eagle is a cruise missile and comes down to wave tops (height depending on the sea state) after achieving a radar lock.
IN also operates VTOL (Vertical Take-Off and Landing) Sea Harriers. INS Viraat carries 12 Sea Harriers and 6 Sea King ASW helicopters. Our anti-ship missions may face Sea Harriers and Jaguars in battle with them.

The Air Defences of Ships
The Exocet-armed Mirage-Vs of PAF can play a significant role in any future naval battle. But while planning these Exocet attacks, the anti-missile and anti-aircraft defences of a ship must be kept in mind. The best solution would be to disable or destroy the air defences of a ship and then continue with the attack. The anti-radiation missile attack can disable the air defences of a ship other than manned gunnery.
If the automatic air defences of a ship are destroyed or disabled, then the fighters can also bomb the ship.
The Indian Delhi class destroyers carry SA-N-7 and SA-N-11 systems. SA-N-11 is a naval version of SA-19 SAM system used in Tunguska AD system and is effective in short range. SA-N-11s are also fitted to three Krivak-3 class frigates in Kashtan air defence system.
Each of the Indian three Navy Delhi class destroyers carry 48 SA-N-7s. The SA-N-7 is a naval version of the SA-11 Gadfly. Its range against fighter jets is 30km and against missile targets is 12km. EO (Electro-Optical) tracker and Laser Range Finder support its engagement radar. Its radar can direct missiles to one target at a time. The three Kashin-2 destroyers are fitted with SA-N-1 systems with a range of 30km, which is the naval version of SA-3 SAM system.
If India acquires AEW (Airborne Early Warning) systems and dedicates one of them for maritime reconnaissance, then it will be difficult to attack the Indian ships. Recently, Indian Navy acquired four Ka-31 AEW helicopters. The Ka-31 AEW helicopters can provide early detection of enemy ships and fighters that are below the helicopter. The surveillance range of E-801E radar fitted on Ka-31, for ships is about 250km and for fighter size targets is about 100-150km.
Pakistan Navy has SM-1MR (RIM-66) Standard air defence missile system, whose range against fighters is 40km at medium altitude. This missile has semi-active radar guidance, thus the fire control radar is able to handle only one target at a time, like the Indian SA-N-7s.
The type-21 frigates of PN are fitted with Chinese LY-60N AD missiles. Its engagement radar can carry out a single interception at a time with semi-active radar homing. Its maximum range is 18 km and minimum is 1km. Its minimum engagement altitude is 30m, meaning that they will not be able to intercept sea-skimming anti-ship missiles which cruise at 2-5m altitude during terminal phase. The air defence and missile defence of Type-21 frigates should be improved because in the British service two Type-21s were lost to air attacks and they were retired soon after the Falklands War in 1982.
In the Falklands War, the British ships shot down many Argentine Mirages and A-4s with Sea Wolf, Sea Cat and Sea Dart air defence systems.
The Fleet Defenders also play a crucial role in air defence of the ships. In the Falklands War, the defending combat air patrols of Sea Harrier successfully shot down a large number of attack force of Argentine Mirages and A-4 Skyhawks. These formations attempted a direct attack on the British Task Force, thus coming in the range of air defences. For such attacks, Escorts must provide cover to the strike formation. The most threatening combination was the SuperEtendard with Exocet missiles, which attacked from a standoff range.
Anti-Missile Defence
AM-39 Exocet anti-ship missile proved itself in Falklands War by sinking the HMS Sheffield and HMS Atlantic Conveyor and damaging HMS Glamorgan. But other British ships that were protected by Sea Wolf anti-missile system remained safe. No Sea Wolf equipped vessel was hit. Now the Indian Navy has purchased six Barak anti-missile systems that provide defence for ships against sea-skimming threats.
INS Viraat is also fitted with Barak SAM system. The maximum range of Barak system is 12km against fighter jets and 5km against sea-skimming threats.
So in addition to Phalanx CIWS (Close-In Weapon System), PN must equip at least its six Type-21 frigates with a self-defence missile system to efficiently handle the sea skimming missiles. These frigates must have a layered defence against the AShMs. The first priority should be to destroy all the fighters that carry these missiles before they can reach the launch range of their anti-ship missiles. This necessitates dedicated maritime surveillance aircraft like Atlantic and P-3C Orion to inform friendly fighters and ships of any enemy activity in time. The fighters always form the outermost defensive layer of naval ships. Fighters will be needed to combat the Indian maritime strike Jaguars that are equipped with Sea Eagle AShMs.
The next layer of defence is the anti-aircraft missile and gun systems on the ships. But anti-aircraft defences may not play a major role keeping in view the long ranges of modern anti-ship missiles, which are nowadays powered by small jet engines giving them a longer range than air defence missiles fitted on the ships. As a result, the ship will have to fight the missile that is coming at wave-top level.
Radar receivers or ESM (Electronic Support Measures) system can warn a ship of the incoming anti-ship missile when that missile gets a lock on that ship. Kh-35 locks on its target at a distance of 15-20kms. Thus the ship will be warned when the missile is just 15kms away. In this short time all self-defence systems should be tried. It will be better to try more than one countermeasure at the same time like firing decoys and anti-missile missile at the same time. The last defence against a missile that is almost a kilometre away is the CIWS along with full decoy firing and manoeuvring the ship at the same time. Some AShMs switch on their terminal guidance radar close to the target at about 10km to give less warning to the ship and leave little time for defences. To get ample warning of AShMs, the best solution is some form of AEW (Airborne Early Warning) system.
Before locking on the target ship, most anti-ship missiles fly at cruising altitudes and it is easy to intercept them at that height. After radar or seeker lock, the missiles descend to very low-level, which makes the detection and defence very difficult. If an AEW aircraft gives warning about the launch of AshM, which is flying at low-level even before getting a radar-lock, then we know that every anti-ship missile with active radar seeker is programmed to go to some height to get a radar-lock of the target. This takes place usually at 15-20 km from target. This is the point to intercept them with a quick-reaction SAM system. Here the AEW platform shall inform the ship defences about the range, bearing and heading of the incoming missile with a real-time data link and when the AshM pulls up for radar lock, it will become visible on the radar screen of the ship and thus intercepted quickly.
The ship’s electronic system should be able to discriminate between the radar lock of a fighter jet and that of an anti-ship missile. An anti-ship missile can be launched from aircraft, another ship or submarine. All of these three launch platforms usually fire the missile after detecting and locking on the enemy ship. Thus the target ship is warned of the impending disaster. All information about the range and bearing of the target ship is transferred to the missile computer and then missile is fired. On this occasion the single blip on the radar screen of the ship or AEW platform will change to double blips indicating the missile launch.
After this launch, the ship should follow a course at about 90 degrees to the original direction and cruise on its maximum speed because the AShM searches the target in the area provided by the radar of its launching platform. This will make it difficult for the terminal radar seeker of the AshM to detect and hence lock on the ship. This method can be effective if the AshM receives no mid-course updates from its launch platform, which is the usual method. But if some AShM gets updates, then even after the missile launch, it must be tried to shoot down that fighter or at least force him to bug out to break its radar lock of the ship. But if they get a radar-lock from the missile, then the ship and its staff should be ready for the final battle.
But here the slow speed of the ships may not allow them to go too far to escape the radar seeker of AShM. We assume that an AShM gets radar lock at a distance of 10km from its target ship. If the ship is cruising at 35knots (64.85km/h) and missile at 600km/h, then the missile will take less than a minute to reach the ship and the ship will have gone away only 1km. The above technique can be more useful for fast attack boats against anti-ship cruise missiles and totally useless against supersonic rocket-powered AShMs.
The Sea Eagle is very efficient in the job of searching the ship in the ‘Ambit’ mode and its radar scans more area as it nears the target location in a way that the area of the radar coverage increases but centre of the area under scan remains the same as supplied by launch aircraft.
All above discussion is about active-radar guided AshMs. This is not the only seeker for anti-ship missiles. These also have IR (Infra Red) and IIR (Imaging Infra Red) seekers, which are passive seekers and give no warning to the target ship. The ship will have to look for these sea-skimming threats.
The missile-based terminal defence system should be able to destroy both the radar-guided and IR-guided AShMs like the RIM-116 RAM (Rolling Airframe Missile). It has a dual mode seeker in which IR-seeker is coupled to two RF antennas. The RF receiver locks on to the active radar seeker of the AShM. When sufficient IR signal is received, guidance control is shifted to IR-seeker, which homes in on the incoming missile’s heat emissions. During tests RAM successfully intercepted MM40 Exocet. Once launched, the RAM needs no support from the mother ship, thus enabling multiple-target engagements. Its maximum range is 10km and a manoeuvring capability of 20g.

Conclusions & Tactics
A very important thing is the use of airborne powered decoys that can present the RCS (Radar Cross-Section) equal to that of a fighter jet. In this way the air defences of a ship can be saturated.
The RGM-84 and UGM-84 Harpoons belonging to Block1A do not have sea skimming profile, they climb to 1800 metres after obtaining radar lock and make a 30 degree diving attack on the ship. The best attack will be to use a combination of sea-skimming Exocet from Sea King helicopters and dive attacking Harpoon from submarines along with powered decoys. The decoys used in conjunction with anti-ship missiles should have RCS equal to that of an anti-ship missile.
The indirect attack capability of Block1B Harpoons can also be very helpful. Block1B Harpoons also feature improved range and ECCM features. For Pakistani ships and submarines, the technique can be to fire two Block1B Harpoons, one directly and other indirectly (if PN possesses Block1Bs), both in the sea skimming profile.
Another possible scenario is that two AShMs are fired on a modern frigate or destroyer, one with terminal radar seeker and another with terminal IIR seeker. These two shall require different countermeasures to be defeated (except CIWS) and thus complicating the job of a defender.
A fact worth mentioning is that some Indian AShMs are of longer range than Pakistani counterparts, especially the 3M54E Club missiles, having a maximum range of 220km.
These long-range missiles have made Indian SSK fleet fairly capable, but the AIP (Air Independent Propulsion) system of Pakistani Agosta-90 SSKs is still a technological edge. Pakistani ships shall now have to work in conjunction with submarines and maritime strike fighters. Also maritime surveillance and ASW (Anti-Submarine Warfare) assets need to be increased along with the modernization of the existing assets. Naval UAVs can also be a good addition to the surveillance fleet.
PN’s RGM-84 and UGM-84 Harpoons have a range of 130km (equal to IN’s Kh-35 Uran), C-802 has a range of 120km, HY-1 has a range of 85km, and AM-39 Exocet having a range of about 70 km.
With the introduction of PJ-10 Brahmos AShM in the Indian Navy, this factor will become more obvious. The range of the Brahmos anti-ship missile is 300km in a launch, cruise and sea skimming terminal engagement profile. In the full sea skimming engagement profile, its range is 120km. Hence the PN’s missile boats armed with HY-1 AShMs seem at a disadvantage with regard to range. They can be used against IN’s missile boats and against large vessels if they are able to achieve surprise or somehow nullify the range advantage of the enemy.
The initiative will certainly be in the hands of those having longer-range missiles and associated sensors for detecting, identifying and tracking targets at extreme ranges. The one with shorter-range weapons will certainly be defensive at least at the start of the battle. Here the Exocet-armed Mirages and naval Sea King helicopters can be brought forward to offset the disadvantage of short-range missiles. But the IN can do the same with their Sea Eagle equipped Sea Kings, Sea Harriers and Jaguars.
If possible PN Sea Kings should be equipped with some air-to-air weaponry to shoot down IN Sea Kings and then use their Exocets. This Sea King to Sea King combat is not far from reality.
If a frigate or destroyer is of huge size, then the number of anti-ship missiles should be increased. As an estimate, two Harpoon hits would be required to disable a destroyer, four for a cruiser and almost eight for a conventional aircraft carrier. For a high kill probability in case of a hit, the AShM should hit close to the waterline and ideally in the vicinity of the engine room.

Penetrating the Ship Defences
Most terminal ship defence systems against sea-skimming threats like Phalanx CIWS (up to 1.5km), RAM, Barak, and Sea Wolf etc work in about 5-10km ranges. An anti-ship missile gets radar lock of its target at about 10-15km distance, thus the effectiveness of the these defensive systems can be reduced if the anti-ship missile flies at Mach 3 plus speed in the terminal phase. Such a high speed can be achieved with ramjet-powered missiles (like Brahmos missile) or high-speed solid-rocket motor (like Club missile). Presently, only Russians are the ones that can provide these high supersonic AShMs. In future we may see Europe and USA with such high-speed AShMs.
Other alternatives to high speed for AShMs are the terminal manoeuvrability with resistance to both ECM and chaff/flares or the application of stealth technology. All these three options allow better penetration through terminal air defences. Terminal manoeuvrability (based on the memorized target position) can be an alternative or supplement to the high speed.
The follow on to the Norwegian Penguin is the Kongsberg NSM AShM, which was designed with high emphasis on stealth features. Its design features RCS shaping, low IR signature and reduced smoke propellant. It is a high subsonic missile with 150km range. It has INS+GPS guidance with an IIR seeker. The stealth features of NSM shall make it difficult for target ship to detect it at sufficient range to intercept it. The NSM can be launched from naval helicopters.
Another good approach for evading ship’s defences is fibre-optic guidance featuring permanent man-in-the-loop. This approach has been adopted for the EADS Polyphem AShM. The fibre-optic guidance allows it to defeat all possible ECMs (Electronic Counter Measures) and IRCMs (Infra Red Counter Measures) like chaff, flares, and jammers etc. In other words, Polyphem shall be resistant to all “soft kill” methods but shall remain vulnerable to hard kill methods like CIWS and missile-based terminal defence. The range of Polyphem is 60km and has a cruise speed of Mach 0.6. NSM has the ability to navigate through complex coastal topography and thus also attack land targets.
Another very important feature of anti-ship missiles is their programming and “Intelligence”. The chaff, which is used by ship to present false target to the incoming missile, is usually tailored for a specific frequency range before launching. If the missile is intelligent, then it can be programmed to jump to another frequency when it detects another target (in fact chaff) after its first lock on the target ship. This will render chaff useless and missile shall re-lock its true target. This feature is available with missiles having frequency-agile radar seekers like in the Swedish Saab RBS-15 Mk3.
RBS-15 Mk3 is an intelligent and quite capable AShM having a flight range of 200+ km. It features GPS mid-course navigation updates, frequency-agile radar seeker, a 200kg warhead, versatile trajectory and extremely low-level sea-skimming flight with sea-state adaptation. It can support a large number of waypoints and has sophisticated target discrimination and selection system. The Missile Engagement Planning System of RBS-15 allows several missiles to attack the ship from different directions with coordinated time of arrival at the target.
The newer missiles also do not need to maintain a continuous lock-on of the target as was needed with older missiles. The missile needs to operate its radar seeker only at intervals to update the target position. This is logical because the ship can be considered stationary when compared to the speed of an AShM. This is a great jump in missile improvement, since the jamming task shall be more difficult now.
Another ECCM (Electronic Counter Counter Measure) feature is the use of LPI (Low Probability of Intercept) radar seekers in anti-ship missiles. LPI technology combines frequency-agility and power management in a way that its emissions are taken as background noise and ESM system of ship is deceived. Another good option is the use of Laser Range Finders and Laser Target Illuminators, which is difficult to detect (due to lack of laser warning receivers) and counter by the ship.
Chaff rockets are fired after the missile gets its radar lock of the ship. An intelligent missile can be programmed to reject the second radar echo near to the first one and continue attack on the first one. Alternatively, typical RCS ranges of different ships (Carrier, cruiser, destroyer, frigate, corvette etc) can be stored in the missile’s computer. During attack the RCS of a known ship type should be compared with one the radar is seeing, thus rejecting the chaff (which usually creates a much larger RCS).
Almost all of the new generation anti-ship missiles have the capability to attack land targets. If an AShM is of long range, it now has the facility of mid-course updates.
PAF and PN should also acquire such a long-range intelligent AShM. It should feature frequency-agile radar seeker, versatile trajectories, capability to attack land targets, and possibly stealth features.
Strike against the Carrier
It would be really a feat in the history of maritime warfare if the PAF succeeds in sinking or seriously damaging the Indian aircraft carrier INS Viraat and a possible mission should be planned for it. But this mission against the carrier is almost impossible without anti-radar and BVR air-to-air missiles, because the sequence of attack may look like the following.
For this we assume that PAF has acquired the French Rafale fighters. It is also an advantage that fleet defenders of Viraat, i.e., Sea Harriers are not equipped with BVR AAMs but on SOS call, the IAF may come to help.
First, with BVR AAMs, a formation of two Rafales shall shoot down most of the airborne fleet defenders patrolling at about 150-100km from the carrier and then patrol at the same range at high-altitude to deal with more scrambles from the carrier or any interception effort of IAF. A second formation of two Rafales, shall shoot down the defending fighters at a range of 100-50km from the carrier, mostly the newly launched and then launch at least six powered decoys towards the carrier to simulate the fighters. The decoys shall cause a reduction in the ship’s stockpile of SAMs. A third formation of two Rafales, shall launch eight ARMs (Anti-Radar Missiles) against various surveillance and engagement radars to disable the air defences of the carrier and its escorting destroyers. The ARMs should be launched seconds after the decoys. Thus the ARMs will be able to destroy radars before the SAM launchers and CIWS guns are re-loaded.
At the time of ARM attack, the four Mirages in the fourth formation shall launch their four Exocet missiles at a range of not less than 50km. The distance between the third and fourth formations may be kept up to 5km but the Mirages should fire their Exocets at the time of Rafales launch of anti-radar missiles, because the Mirages will be at a more distance from carrier battle group than Rafales and AShMs shall reach their targets seconds after the ARM strike. Rafales of third formation should return from the attack sequence at a range of 40km from the carrier and also the Mirages of fourth formation at a range of almost 40km. Rafales with their more sophisticated EW suite can defend themselves against any long-range SAMs fired against them.
A fifth formation of F-16s or F-7s should be kept ready to escort the returning strike package, if the Indian fighters are pursuing them. After the Indian acquisition of carrier Admiral Groshkov, the battle shall become tougher if the Mig-29Ks are deployed aboard the carrier.
This attack should be supplemented by two Agosta-90B submarines firing a mix of two sea skimming SM-39 Exocets and two diving Block1A UGM-84 Harpoons, thus complicating the job of missile defence. The submarine attack should be launched simultaneously with Mirages attack, thus saturating the ship defences. Thus this attack would involve four AM-39s, two SM-39s and two Harpoons, sufficient to sink the INS Viraat. Any anti-submarine effort by ASW (Anti-Submarine Warfare) Sea Kings of INS Viraat should be foiled by the attack formations because every fighter will be equipped with air-to-air missiles and guns. The Agosta subs will also face the threat of IN subs defending the carrier battle group.
All AShMs should be carefully targeted against the carrier because in the terminal phase, they shall lock on any ship that their radar seeker detects. In this regard, the direction from which the missile is launched becomes important. The direction should be chosen such that when the missile switches its radar, it should see the carrier. But if the facility of programmable waypoints is there in the missile, then a bit complex path can be followed. The location of escorting ships should be known before the strike, updated to the last minute before the strike package takes off.

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