Surface launched AShMs with land attack capability?

[Scott Kenny]

P.S. One possible solution - some kind of strap-on optic seeker, that could be added to normally anti-ship missile to allow attacks against land targets. Optical seekers aren't exactly big, and if some kind of interface is installed into anti-ship missile body, probably could be easily fitted at its side (in some kind of external blister, probably). So if crew needed to attack the land target, they just strap the optical seekers to normally anti-ship weapons.

Or have the secondary optic seeker built in, so the missiles are dual-use from the beginning.

IIRC, AGM-84 SLAMs are still a viable AShM.

 

[Rule of cool]

I think the late 70s-early 80s is too early to attach EO or IR seekers to active radar AShMs, given the active radar seekers themselves were new technology at the time as were all-aspect IR seekers for AAMs.

While I can't stop thinking about 'modular' seekers heads, removing the active radar head for a datalinked EO, what about dual-role AShMs? The air launched Martel has anti-radar and TV-datalink and the proposed sea-Martel a cheap single-axis active radar, what if a ship was loaded with 2 or 3 of each and the anti-radar and TV-datalink? The anti-radar and TV-datalink missiles could have a secondary land attack capability, much like SAMs have a secondary anti-ship capability, without reducing the ship killing power of the platforms carrying them and likely increasing the ship killing power due to the synergistic effects of 3 seeker type attacks.

 

[Dilandu]

I think the late 70s-early 80s is too early to attach EO or IR seekers to active radar AShMs, given the active radar seekers themselves were new technology at the time as were all-aspect IR seekers for AAMs.

Erm... active radar seekers on anti-ship missiles were standard since late 1950s.

 

[Rule of cool]

Erm... active radar seekers on anti-ship missiles were standard since late 1950s.

What were these Western AShMs in the 50s? What ship classes carried them?

 

[Dilandu]

What were these Western AShMs in the 50s? What ship classes carried them?

There were Soviet ones) While the air-launched KS-1 "Kometa" was combined beam-rider/semi-active homing, the ship-launched KsSH was already active homing one.

 

[Rule of cool]

There were Soviet ones) While the air-launched KS-1 "Kometa" was combined beam-rider/semi-active homing, the ship-launched KsSH was already active homing one.

Soviet weapons development was often out of step with the West, their AShMs were deployed earlier than Western AShMs but were massive. The P15 was 3 times as heavy was the 70s Western missiles, so had much more room for crude 50s active radar seekers.

 

[Dilandu]

Soviet weapons development was often out of step with the West, their AShMs were deployed earlier than Western AShMs but were massive. The P15 was 3 times as heavy was the 70s Western missiles, so had much more room for crude 50s active radar seekers.

Sigh. No. It was big, because it needed to carry battleship-killer half-ton shaped charge warhead. The constant worry of Soviet Navy in late 1950s were large numbers of battleships and cruisers in US/NATO fleets, so early Soviet anti-ship missiles were designed with a goal of killing NATO heavies by over-the-horizon shots.

 

[Yellow Palace]

Erm... active radar seekers on anti-ship missiles were standard since late 1950s.

The USN actually deployed one in 1945, the ASM-N-2 Bat. Granted it wasn't a very good anti-ship missile, but it was in fact active radar guided. Since the USN lost interest in attacking ships at sea in the 1950s, on account of the fact that the Soviet Navy unsportingly decided not to provide it with targets, they didn't bother with improved versions.

Similarly, the UK's Green Cheese was to have had an active radar seeker. It was cancelled in 1955 due to a combination of the missile being useless, the Air Staff being useless, and - once again - a lack of big Soviet ships to sink.

It was big, because it needed to carry battleship-killer half-ton shaped charge warhead.

Funnily enough, carrying a warhead three times the size requires a missile three times the size. I've pointed out in another discussion that the USN studied a large supersonic anti-ship missile in the early 1970s. It was approximately the same size as P-700, to carry a similar sized warhead to a similar range at similar speed.

Nobody had particularly 'better' or 'worse' scientists and engineers - although smaller countries had fewer of them - and differences in equipment are largely due to differing military doctrine or economic circumstances. If the USSR had provided heavy ships for NATO to shoot at, they'd have developed suitable weapons to do so. If NATO had decided to go all-in on missiles carried by smaller ships and submarines, the USSR wouldn't have developed large AShMs.

 

[Rule of cool]

The Tomahawk had a much bigger warhead, fuel tank and electronics package than the Harpoon, so was a much bigger missile, as basic physics would suggest. However the West was generally more technologically advanced than the Soviets so could put more sophisticated electronics into a smaller space and get a bit more range from a given engine/fuel tank size.

My point was the first generation Western AShMs of the 70s were reasonably sophisticated pieces of kit as they stood; Harpoon, Exocet, Komoran and Otomat had a dual axis (PR-53/DSQ-28, Adac & RE 576 respectively) active radar seeker, sea skimming capability, sophisticated warhead and long (for the period) range all within a 1,500-1,800lb package. I don't think it would be possible to add another seeker in addition to the radar seeker to provide a land attack capability in these early missiles. As the development of such missiles continued, and electronics and seeker technology advanced and miniaturised it would become technically possible, but I don't know how long this development would take.

My initial thought was that seeker heads could be changed at sea to enable land attack, but that seems like a hassle. Now I'm thinking that alternative seekers like Martel could come as standard and the Anti-radar and TV-datalink could have a secondary land attack alongside their primary anti-ship role. A Naval Task Element facing a mix of incoming radar sea skimmers, anti-radar and TV-datalink AShMs would have a significant problem on it's hands.

 

[Dilandu]

Nobody had particularly 'better' or 'worse' scientists and engineers - although smaller countries had fewer of them - and differences in equipment are largely due to differing military doctrine or economic circumstances. If the USSR had provided heavy ships for NATO to shoot at, they'd have developed suitable weapons to do so. If NATO had decided to go all-in on missiles carried by smaller ships and submarines, the USSR wouldn't have developed large AShMs.

Exactly

 

[Dilandu]

However the West was generally more technologically advanced than the Soviets so could put more sophisticated electronics into a smaller space and get a bit more range from a given engine/fuel tank size.

And USSR deployed S-10 "Granat" (as well as ground-based RK-55 "Relief") - a strategic, subsonic, low-altitude cruise missile - in 1984. Basically at the same time as first strategic "Tomahawks" TLAN were deployed. And it was essentially identical to "Tomahawk" in everything that mattered, up to weight and range. Your thesis about "better Western electronics making Western missiles more compact" just isn't true. The large size of Soviet cruise missiles was purely doctrinal - Soviet Navy wanted a weapon that could mission-kill large warship in one hit, that's why heavy warheads were viewed as essential.

 

[Yellow Palace]

My point was the first generation Western AShMs of the 70s were reasonably sophisticated pieces of kit as they stood; Harpoon, Exocet, Komoran and Otomat had a dual axis (PR-53/DSQ-28, Adac & RE 576 respectively) active radar seeker, sea skimming capability, sophisticated warhead and long (for the period) range all within a 1,500-1,800lb package.

Let's compare a successful Western AShM (SM39 Exocet) to a Soviet contemporary (P-70 Ametist).

Entered service: Exocet 1975, P-70 1967
Propulsion: both solid rocket
Launch: both submerged submarine
Range: Exocet 50km, P-70 65km
Warhead weight: Exocet 165kg, P-70 1000kg
Missile weight: Exocet 780kg, P-70 3500kg
Warhead-to-missile ratio: Exocet 21%, P-70 29%

The improved P-120 entered service in 1972 with a datalink and turbojet propulsion, making for a missile more comparable to Otomat (which entered service in 1976). Here, the ranges are again pretty similar, and the warhead-to-weight ratio is the same to within a rounding error.

It's very hard not to come to the conclusion that the Soviet Union was producing better anti-ship missiles earlier than the West. But Otomat was pretty tasty for its size.

Your thesis about "better Western electronics making Western missiles more compact" just isn't true.

I think this belief comes from the fact that Western missiles were better than Soviet ones at some things. Namely the things that Western armed forces valued and that Soviet ones didn't. Meanwhile, the things that the Soviets valued and Western armed forces didn't, the West happily dismissed as irrelevant or even weaknesses of Soviet weapons systems.

The example we've discussed before is command-link guidance. The West considered that to be a weakness as it introduced a dependence on a third party. But for a USSR which considered that dependence to exist anyway, it was a significant improvement to the effectiveness of the weapon system.

Ironically, I think an awful lot of the West's 'revolutions' in military thinking over the last thirty years or so can be subtitled 'actually, the Soviets were right all along'.

 

[Scott Kenny]

My point was the first generation Western AShMs of the 70s were reasonably sophisticated pieces of kit as they stood; Harpoon, Exocet, Komoran and Otomat had a dual axis (PR-53/DSQ-28, Adac & RE 576 respectively) active radar seeker, sea skimming capability, sophisticated warhead and long (for the period) range all within a 1,500-1,800lb package. I don't think it would be possible to add another seeker in addition to the radar seeker to provide a land attack capability in these early missiles. As the development of such missiles continued, and electronics and seeker technology advanced and miniaturised it would become technically possible, but I don't know how long this development would take.

By the early-mid 1980s, IIR was completely possible. AGM-65D.

 

[Rule of cool]

By the early-mid 1980s, IIR was completely possible. AGM-65D.

Yes, 100% true. But the question is could that be scabbed onto a more or less standard Harpoon to make it into a land attack missile?

 

[Scott Kenny]

Yes, 100% true. But the question is could that be scabbed onto a more or less standard Harpoon to make it into a land attack missile?

Maybe?

SLAM is basically a Harpoon with the radar seeker replaced by the Maverick IIR seeker.

You could probably do a little modification work to put the IIR seeker on top of the radar seeker (to dorsal, I mean), though it wouldn't be a simple cylindrical missile body anymore.

But frankly, IMO you'd be better off using the IIR seeker instead of ARH.

 

[Rule of cool]

I don't deny that due to different strategic circumstances the Soviets started deploying AShMs about 13 or so years before the west and were on their 4th (?) type as the West were introducing their initial types. The huge headstart, a full quarter of the Cold War's duration, and the size of these missiles meant that by the early-mid 70s they had some cool capability. I really like the salvo cooperation, where one missile flies higher and feeds info to the rest of the salvo.

This does not mean the Soviet aero and/or missile technology was better than the West, only that the Soviets had successfully pursued an area of strategic interest to them with the technology at their disposal. If the Soviets were better than the West at missile technology in general that would be evident in air to air and tactical air to ground missiles, but it most certainly wasn't. I'd suggest that a Western advanced arms manufacturing nation given the same brief as the Soviets at the same time could deliver somewhat superior performance in the same size or the same performance in a somewhat smaller package.

 

[tomo pauk]

FWIW, the Taiwanese Hsiung Feng II missile have had the additional IR seeker to help out the ARH seeker. While a simple IR seeker is not as good a hing as a thermovision camera, it kinda points us to a possible solution - basically, the missile that can attack both the targets with high RF contrast (basically, ships) and the ones the man in the loop can see (again ships, but also the discernable ground targets). Yes, it will need a data link, and the helicopter will add to the usable range a lot.

 

[Rule of cool]

Maybe?

SLAM is basically a Harpoon with the radar seeker replaced by the Maverick IIR seeker.

You could probably do a little modification work to put the IIR seeker on top of the radar seeker (to dorsal, I mean), though it wouldn't be a simple cylindrical missile body anymore.

But frankly, IMO you'd be better off using the IIR seeker instead of ARH.

IIUC in the 1991 PGW A10s with IR mavericks would take off at night, turn on the seeker on a maverick and tool around so the narrow seeker view would find a target. When the seeker found something the pilot would fire the Maverick.

My question about an IIR seeker on an AShM isn't that it can't hit targets, its that it can't tool around to find and lock onto a target without someone in the loop.

 

[Scott Kenny]

IIUC in the 1991 PGW A10s with IR mavericks would take off at night, turn on the seeker on a maverick and tool around so the narrow seeker view would find a target. When the seeker found something the pilot would fire the Maverick.

My question about an IIR seeker on an AShM isn't that it can't hit targets, its that it can't tool around to find and lock onto a target without someone in the loop.

A target image library can be loaded on, and you can program the missile into doing those sweeping turns for searching.

Depends on relative field of view between the radar and IIR systems.

 

[Rule of cool]

Depends on relative field of view between the radar and IIR systems.

IIUC the FoV for those early IIR Mavericks in 1991 was 2.5 degrees. It was like searching for tanks by looking through a drinking straw, but in practice it turned out to give results worthwhile enough to use it regularly.

A target image library can be loaded on, and you can program the missile into doing those sweeping turns for searching.

Sure, but that sounds like late 80s tech or more likely early 90s, whereas anti-radar and TV-datalink could likely be deployed in the 70s like it was in the Martel.

 

[Dilandu]

A target image library can be loaded on, and you can program the missile into doing those sweeping turns for searching.

It's not that simple. You need a pretty big image base for the recognition pattern model to work with. 1980-1990s digital systems weren't exactly good in that matter.

P.S. Contrary to popular belief, Tomahawk didn't use "target image" loaded in DSMAC system. It used the image of some reference point, that could easily be recongized near the target. Some terrain object, like hill of specific shape, or road juncion, or village with specific street pattern. This easy-to-recognize reference point was loaded into DSMAC - as well as direction and distance from reference point to target. The missile searched not for target, but for reference point (since target could be hard to observe, could be camouflaged, could be covered by smoke screen or could change shape). And from reference point, missile calculated the exact position of target in close proximity.

 

[Scott Kenny]

IIUC the FoV for those early IIR Mavericks in 1991 was 2.5 degrees. It was like searching for tanks by looking through a drinking straw, but in practice it turned out to give results worthwhile enough to use it regularly.

So, definitely going to have a "snake search" pattern programmed in then.

 

[Rule of cool]

So, definitely going to have a "snake search" pattern programmed in then.

It seems a hard way to go about a secondary capability. I can easily imagine it as time goes on, indeed we have seen it, but not in the first generation of dual-purpose missiles.