Defences against supersonic anti ship missiles

[STURM]

Hello,

Do systems like the Seawolf, RAM and Sea Sparrow provide any capability against supersonic anti-ship missiles like the Sunburn, Klub, etc.
And what about Phalanx and Goalkeeper?

Thank you.

[Feanor]

To some extent. Depending on the missile, the number of missiles, and which of the particular systems we're looking at. In my opinion it's more effective to shoot down the plane before it launches the missiles then to try to build a defense system with high enough saturation points to withstand the missile attacks.

[kato]

RAM is regularly tested against supersonic low-altitude evading drones, successfully. And is about the only close-in weapon system that brings both range (>10 km) and volume (in the form of 21-cell launchers).

[STURM]

Sorry for being a bit off-topic here but on paper, which system is more capable of defending against sea skimming missiles - VLS Seawolf or RAM?
Totally agree that the best solution would be to deal with the aircraft before it can launch, but for many non-NATO navies, the onboard missiles systems and soft kill options are the only line of defence against missiles.

[tphuang]

Sorry for being a bit off-topic here but on paper, which system is more capable of defending against sea skimming missiles - VLS Seawolf or RAM?
Totally agree that the best solution would be to deal with the aircraft before it can launch, but for many non-NATO navies, the onboard missiles systems and soft kill options are the only line of defence against missiles.
I would guess RAM from all the investment they put into it and the number of forces using it.
The thing I like about RAM is that it's so compact. But I think in the future, a lot of the newer CIWS will be gun-based, so all these missile based ones might be a thing of past.

[Tony Williams]

But I think in the future, a lot of the newer CIWS will be gun-based, so all these missile based ones might be a thing of past.
That depends very much on the gun, I think. The current generation of gun CIWS like Phalanx and Goalkeeper only have an effective range of about 1.5 km, which gives them very little time to shoot down an incoming supersonic. Even if they hit it, the momentum might mean that the missile wreck ploughs into the ship. The 35mm Millennium ought to do a bit better than that for range, but it doesn't hit as hard.

The 76mm OTO firing DART guided anti-missile ammo is a possibility for the future because it will have a much longer range, although I would like to see it demonstrated first...

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)

[kato]

Mmm, that depends. Phalanx hits harder if it hits, but Seaguard (Millenium) has a better chance to hit a target at all, considering its wider kill zone dispersion through the AHEAD subprojectiles.
Considering the difference in range, for a single Mach 2 terminal phase target either system can pretty much exactly apply two bursts in a kill attempt within its respective intercept envelope, but would likely only apply a single burst at the outer half of the intercept envelope.

Phalanx fires standard 100-round bursts against missile targets* - that's 1.3 seconds per burst - and puts up 100 projectiles of considerable mass (150g) with low dispersion (engagement mass: 15 kg).
Seaguard fires 27-rounds bursts against missile targets* - 1.6 seconds per burst - and puts up 4100 projectiles of low mass (3.3g**) at high dispersion (engagement mass: 13.5 kg).

If engaging with continuous fire against a single (subsonic) target, Phalanx can put up 1,550 projectiles (Block 1 magazine) at medium dispersion over 20 seconds, whereas Seaguard (ARM magazine) can literally create a cloud of steel... err, tungsten - 70,000+ projectiles over 27 seconds.

*- differs in anti-surface (shorter) and C-RAM (longer) roles of course
**- using the heavy subprojectile version; for counter-missile work, originally it was supposed to use the same 25-grain subprojectiles (341 per shell) as the 30mm AHEAD rounds, but the 55-grain version saw better behind-armour effect.

[Tony Williams]

Mmm, that depends. Phalanx hits harder if it hits, but Seaguard (Millenium) has a better chance to hit a target at all, considering its wider kill zone dispersion through the AHEAD subprojectiles.
That's certainly true. I'm just a bit concerned at how effective the hits with lots of small tungsten pellets will be against a big supersonic missile which probably has an armoured warhead. They might kill the guidance system but even if the missile goes ballistic, at such a close engagement distance it could still hit the ship.

for counter-missile work, originally it was supposed to use the same 25-grain subprojectiles (341 per shell) as the 30mm AHEAD rounds, but the 55-grain version saw better behind-armour effect.
There are currently three sizes of pellets in 35mm AHEAD:

1. The standard AA/anti-missile loading has 152 at 3.3 gram (c.51 grain)

2. The anti-personnel loading for use in MICVs (formerly known as ABM for air burst munition, now known as KETF - kinetic energy time fuzed) originally had 341 at 1.5 g (c.23 grains), but I'm not sure if they've now adopted the smaller 30mm ones (see below).

3. The C-RAM load, still in development, uses a smaller number of bigger pellets not made from tungsten but out of a new reactive material (aluminium and fluorinated plastic have been mentioned) but I don't have details of the weight or number.

The 30mm load is known as KETF, not AHEAD, as it's for anti-personnel use. It was originally loaded with 135 of the 1.5 g pellets, but this has recently changed to 162 at 1.24 g (19 grains).

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)

[Abraham Gubler]

These CIWS weapons are designed to engage different types of missiles. The Phalanx was designed in the 1970s when the threat missiles almost all flew on solid fuel rocket or turbojet motors (eg STARBRIGHT, SIREN, Exocet, Harpoon). To destroy a solid fuel missile all you need to do is ignite the fuel by a solid hit. So Phalanx was designed to fire APDS ammunition that could hit the nose of the missile and pass through the body and nick the solid fuel, leading to a huge explosion as the fuel detonated and destruction of the missile.

Against liquid fuel powered missiles APDS ammunition is not going to cause a catastrophic explosion with even multiple hits. Older liquid fuel missiles like STYX were slow, big and flew high g enough that the Phalanx could chew them up with multiple hits and hopefully they would fall out of the sky into the drink.

The terminal engagement problem with liquid fuel ramjet weapons like SUNBURN is far harder. The missile itself is much more resilient to damage thanks to liquid fuel and the very simple and multiple ramjet engines. Since it is faster it offers less engagement time and since it flies low it can keep on coming after having its guidance and flight systems destroyed and still hit the ship.

The terminal engagement of an AHED round tends to be pretty lethal against a missile body. The key aspect for avoiding ‘ballistic’ hits after interception is to do so at a long range. CIWS against solid fuel missiles relied on pretty close range interceptions (down to under a few hundred metres) because the intercepted missile blow up so spectacularly. To achieve a ballistic hit after interception the missile needs to be very close to the ship if sea skimming or on an interception path if it higher altitude (ie no last minute divers). This is why block improvements to Phalanx have strongly focused on improving accuracy at longer range. AHED is also a very lethal system at longer gun ranges (>1km).

But the best way to take down a big supersonic, liquid fuelled missile like SUNBURN or Moskit is with a direct interception by a big missile or shell. Which is why OTO have been working on the guided 76mm round and ESSM is so popular.

[STURM]

What about the Bofors 57mm Mk2. Without 3P, can it deal with sea skimmers?
Also, I am correct in saying that due to the size of its 127mm shell, the US
Mk-45 127mm gun is more suited for providing naval gunfire support to ground troops rather than dealing with fast moving air threats.

Not to go off topic, but the reason I started this thread was because it occured to me that until the arrival of the Aster on the Daring class, the RN only has the Sea Wolf to deal with supersonic threats like Sunburn, Klub and Brahmos [Im assuming here that Sea Dart is unable to deal with supersonic missiles]. The advantage for NATO navies and others like Japan and South Korea, is that money has been invested for soft kill solutions. Plus the fact that NATO navies would most certainly be operating under a protective air umbrella. But for smaller navies like Malaysia, Chile, etc, systems like Sea Wolf and main guns are the first line of defence. Granted, the Royal Malaysian Navy's frontline ships are equipped with jammers and chaff launchers, but I would still put more faith in a hard kill solution. I think the fact that the Israeli Eilat corvettes have a Phalanx as the main gun, says a lot about their threat perceptions. The Germans and South Koreans seem have adopted the best solution, relying on a RAM to supplement the gun and missile systems on the Sachsen and KDX 3.

[Tony Williams]

What about the Bofors 57mm Mk2. Without 3P, can it deal with sea skimmers?
3P has now become the standard for this round, I believe, so it may be an academic question. The Canadian Halifax class are due to have their guns upgraded from Mk II to Mk III to handle it. I doubt that the 57mm could cope without this change (and presumably upgraded FSC software).

Also, I am correct in saying that due to the size of its 127mm shell, the US Mk-45 127mm gun is more suited for providing naval gunfire support to ground troops rather than dealing with fast moving air threats.
Certainly - that's why the gun has a lower rate of fire and lower elevation than its predecessor.

Im assuming here that Sea Dart is unable to deal with supersonic missiles].
I'm not so sure. It was originally expected to cope with supersonic planes, and it's been upgraded over the years. The main problem it faced was in fuze function very close to the water, but judging by its success in swatting a Silkworm in the Persian Gulf this may have been overcome.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)

[Uhu]

To destroy a solid fuel missile all you need to do is ignite the fuel by a solid hit.
I have some doubt that this works with KE ammo like Phalanx' APDS.

[kato]

I have some doubt that this works with KE ammo like Phalanx' APDS.
Phalanx originally used a DU projectile, with the usual incendiary properties.

[Abraham Gubler]

I have some doubt that this works with KE ammo like Phalanx' APDS.

Well it doesn't work by igniting the solid fuel in an incendiary sense. Like someone lighting a match to it. Tungsten APDS ammo is just as likely to detonate solid fuel as is DU APDS ammo. The APDS round ignites the solid fuel by disrupting its steady state. Wether you believe this or not is immaterial. This IS the method relied upon to destroy ASMs by many CIWS. It may be counter-intuitive but its reality.

[Feanor]

In this regard are CIWS an effective AA solution on land as well? Or does it not make sense, due to the large numbers that would be necessary to cover the land forces?

[Alatien]

Intuitively, the better defence against the supersonic seaskimming missiles are counter-missiles (CM). Mainly due to long engagement range (~10 km). Meaning that you can fire 2 or possibly more counter-missiles at the incoming threat. In addition, targeting is easier with highly maneuverable CM, and it can be fire and forget. This way the ship can start evasive manuevers (whichever it can do in 10 seconds), which would otherwise obstruct its gun-based CIWS. Plus as already mentioned CM can easier accommodate an exploding warhead vs liquid powered threats. Also, several CMs launched from a single unit can engage several targets without degradation of performance - something a gun system cant do. For navy, missiles are the future of CIWS. Possibly supplemented by high-power microwave or lasers to destroy tracking.

Guns are indeed better suited for land based applications where engagement range is far shorter (< 1 km). There are several land based active defence systems which use shotgun/shrapnel like fire to destroy the incoming missile 10 m away from the vehicle. Thou even these systems are useless against heavier APFSDS threats.

[Tony Williams]

OTO Melara have of course come up with an intermediate solution: a guided discarding sabot round for the 76mm gun.

See: http://www.otomelara.it/EN/Common/files/OtoMelara/pdf/business/naval/development/STRALES.pdf

[Firn]

Hm an interesting combination which could be a great success as it uses the main gun and thus needs no further space. The radar frequency guidance is of course jammable, but then again it should be employed mainly against fast aerial threats. It also should keep the cost per shot down. A very low rate of fire compared to the other CIWS, but a faster and heavier projectile which will be guided. So it could be able to take down even hardened and maneuverable missiles, and that at longer rangers - provided the system works as advertised....

[jaffo4011]

3P has now become the standard for this round, I believe, so it may be an academic question. The Canadian Halifax class are due to have their guns upgraded from Mk II to Mk III to handle it. I doubt that the 57mm could cope without this change (and presumably upgraded FSC software).


Certainly - that's why the gun has a lower rate of fire and lower elevation than its predecessor.


I'm not so sure. It was originally expected to cope with supersonic planes, and it's been upgraded over the years. The main problem it faced was in fuze function very close to the water, but judging by its success in swatting a Silkworm in the Persian Gulf this may have been overcome.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)

and lets not forget that these missiles dont generally 'chase' incoming missiles they are mostly 'head on' or 'crossing' targets.....

[Tony Williams]

So it could be able to take down even hardened and maneuverable missiles, and that at longer rangers - provided the system works as advertised....
Exactly so. It would be a considerable achievement in the performance of both the guidance system and the proximity fuze to be able to destroy a tough and possibly supersonic anti-ship missile, given the necessarily small HE content of the "Dart" projectile and the closing speed of 1,500-2,000 metres per second.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)

[tphuang]

That depends very much on the gun, I think. The current generation of gun CIWS like Phalanx and Goalkeeper only have an effective range of about 1.5 km, which gives them very little time to shoot down an incoming supersonic. Even if they hit it, the momentum might mean that the missile wreck ploughs into the ship. The 35mm Millennium ought to do a bit better than that for range, but it doesn't hit as hard.

The 76mm OTO firing DART guided anti-missile ammo is a possibility for the future because it will have a much longer range, although I would like to see it demonstrated first...

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)
actually if you read what I wrote. I wasn't dismissing gun based CIWS, i'm dismissing purely missile based CIWS. It seems like there is a move now for gun based CIWS like 76 mm, 57 mm. And from what I know, PLAN's next generation CIWS is going to be improved 30 mm rather than a missile based system.

[Firn]

Exactly so. It would be a considerable achievement in the performance of both the guidance system and the proximity fuze to be able to destroy a tough and possibly supersonic anti-ship missile, given the necessarily small HE content of the "Dart" projectile and the closing speed of 1,500-2,000 metres per second.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)

I'm not an expert on the dynamics of an explosion, so I might ask. If we assume a closing speed of the Dardo of roughly 1500 m/s and one of 500 m/s for the directly approaching missile then we have with roughly 2000 m/s quite some relative speed. Now on top of that comes the acceleration of the explosion. More or less how high would the initial relative speed of the pellets to the target be, when the PF explodes the charge at the edge of a 30° cone seen from the approaching missile?

[Feanor]

What do you guys think of combined gun-missile systems?

[Alatien]

What do you guys think of combined gun-missile systems?

A good example is Russian Kashtan CIWS. It combines 2 x 30mm gatling guns with 4 ready to fire missiles (24 in reload magazine). At the moment it is probaby the most versitile and powerful system. It can engage up to 6 missiles travelling at Mach 3 with 96% kill probability.

Few more details from wikipedia:
The effective range of the missiles is 1,500–10,000 meters up to an altitude of 6,000 m. The engagement range of the guns is 500–4,000 m, up to an altitude of 3,000 m. The guns have a combined rate of fire around 10,000 rpm, and the reloading time for a group of 4 missiles is 90 seconds.

An improvement to Kashtan is Palma, which also has 2x30mm and 4 missiles, and uses optical guidance as primary (radar is backup), and therefore can't be jammed. It can also intercept missiles traveling at Mach 4 and at altitudes of 2m (very sea skimming).

A different approach is taken by Raytheon . They manufacture both Phalanx and RAM (SeaRAM), and the two systems can be mounted easily on the same ship (two separate mounts), and linked so they cooperate. This gives bit more flexibility in installation and operation, but Phalanx is a bit aged, and 20mm has range/impact limitations.

If I had to guess I would say that Kashtan/Palma have an edge over Phalanx+RAM, but it is only an intuitive selection. The test data is not widely available for comparison.

[Firn]

A good example is Russian Kashtan CIWS. It combines 2 x 30mm gatling guns with 4 ready to fire missiles (24 in reload magazine). At the moment it is probaby the most versitile and powerful system. It can engage up to 6 missiles travelling at Mach 3 with 96% kill probability.

Few more details from wikipedia:


An improvement to Kashtan is Palma, which also has 2x30mm and 4 missiles, and uses optical guidance as primary (radar is backup), and therefore can't be jammed. It can also intercept missiles traveling at Mach 4 and at altitudes of 2m (very sea skimming).

A different approach is taken by Raytheon . They manufacture both Phalanx and RAM (SeaRAM), and the two systems can be mounted easily on the same ship (two separate mounts), and linked so they cooperate. This gives bit more flexibility in installation and operation, but Phalanx is a bit aged, and 20mm has range/impact limitations.

If I had to guess I would say that Kashtan/Palma have an edge over Phalanx+RAM, but it is only an intuitive selection. The test data is not widely available for comparison.

As Alatien said they certainly have their place in a specific layer of the "onion" protecting a ship. As point defense weapon they can find both a role on smaller and larger vessel. Once again it is very difficult to compare the effectivness of a certain combination, as many subsystems (launcher, sensors) have to work in conjunction with a far wider one (C4ISR of the ship) and in concert with other assets (AEW&C aricraft, combat aircraft, drones, other ships...).

Personally I think that they are an attractive solution for smaller ships - construction permitting - and possibly for larger ones in the faces of a high threat by anti-ship missiles.

[GI-Gizmo]

I think the threat of supersonic anti-ship missiles needs to be taken more
seriously. China is investing in ballistic missiles capable of striking US carriers far out in the Pacific, Brahmos technology is bound to show up in enemy hands soon, the newer generation of anti-ship missiles are very effective. They are hard to detect and defend against, if multiple missile
barrages were fired at a carrier a few are bound to get through our defenses. A combination of different types of anti-missile missiles, phalanx type weaponary, good situational awareness and development of maturing
directed high energy and laser weapons will be our defenses in the near future. Ofcourse, taking out the missiles in the initial launch phase or on the ground will also be part of the defensive strategy to protect naval assets.
Electronic jamming will also be a big part of confusing enemy missiles.