Low Cost Anti-submarine Weapon (LCAW)

[Voltzz]

LCAW was a NATO program for an small torpedo, cheap/expendable enough to be use against unidentified/unverified sonar contacts. It was supposed to have both rocket-launched and helicopter-dropped version.
At first it was a trilateral US, German Norwegian project, but some point ~1990 The US dropped out.
There seem to have been 3 development teams with the US led one only participation in the first phase:

• NFT (Kongsberg), Whitehead (WASS) and Diehl(?) with the A200
• Lockheed, Dynamit Nobel, Atlas Elektronik, Dyno Industrier and Raufoss with the ULWT (Ultra Light Weight Torpedo)
• STN, HEN and Rheinmetall (later called SeaPike)

The A200 seems to have had the most success and maybe(?) even went into service with the Italian navy.
The article also mentions a very interesting even smaller variant for Special Forces, fired from a handheld launcher.

 

[TomS]

The A200 seems to have had the most success and maybe(?) even went into service with the Italian navy.

Seems like the A200 was not a great experience for WASS (now Leonardo). I suspect it did not actually reach service.

https://cdn.asp.events/CLIENT_Clarion__96F66098_5056_B733_492B7F3A0E159DC7/sites/UDT-2020/media/libraries/2018-presentation/Day-1---Theatre-3---14-40-Alberto-Chiericoni-&-Marco-Melani---5-inches-Platform---ASW-applications.pdf

 

[Voltzz]

I also found a short German article on LCAW from 1993 here
It highlights the differences between the NFT and STN concepts. With the NFT torpedo using a traditional spiral search pattern (and a traditional sonar array), while the STN torpedo would sink vertically unpowered in its search phase and used a side mounted search-sonar while having a separate front mounted attack-sonar.
Especially interesting about these concepts is imo the wide variety of launcher they would fit. The a-200 article above mentions it fitting in sonobuoy launchers on maritime patrol aircraft and this German article talks about the STN concept fitting the existing Breda (10 rockets) and RAM (21 rockets) launchers. With Breda i would guess they mean the SCLAR countermeasures launchers on the Hamburg-Class destroyers.

 

[timmymagic]

Wonder if we'll see a resurrection to target UUV's?

We can't be firing MU-90/Stingray/Mk54 at everyone of those we find.

Can't imagine the warhead would have done a lot of damage against a Soviet sub...it was received wisdom that the far beefier warheads on normal sized LWT's was barely sufficient.

 

[TomS]

Wonder if we'll see a resurrection to target UUV's?

We can't be firing MU-90/Stingray/Mk54 at everyone of those we find.

Can't imagine the warhead would have done a lot of damage against a Soviet sub...it was received wisdom that the far beefier warheads on normal sized LWT's was barely sufficient.

The USN keeps flirting with mini-torpedoes, either as a antitorpedo weapons or submarine weapons for anti-UUV use.

Post in thread 'New mini-torpedo for USN?' https://www.secretprojects.co.uk/threads/new-mini-torpedo-for-usn.33771/post-474275

 

[Scott Kenny]

I also found a short German article on LCAW from 1993 here
It highlights the differences between the NFT and STN concepts. With the NFT torpedo using a traditional spiral search pattern (and a traditional sonar array), while the STN torpedo would sink vertically unpowered in its search phase and used a side mounted search-sonar while having a separate front mounted attack-sonar.
Especially interesting about these concepts is imo the wide variety of launcher they would fit. The a-200 article above mentions it fitting in sonobuoy launchers on maritime patrol aircraft and this German article talks about the STN concept fitting the existing Breda (10 rockets) and RAM (21 rockets) launchers. With Breda i would guess they mean the SCLAR countermeasures launchers on the Hamburg-Class destroyers.

While I suspect that the side sonar was more accurate and would enable a lockon faster, the extra sonar would seem to make for a more expensive system.

 

[Scott Kenny]

Seems like the A200 was not a great experience for WASS (now Leonardo). I suspect it did not actually reach service.

https://cdn.asp.events/CLIENT_Clarion__96F66098_5056_B733_492B7F3A0E159DC7/sites/UDT-2020/media/libraries/2018-presentation/Day-1---Theatre-3---14-40-Alberto-Chiericoni-&-Marco-Melani---5-inches-Platform---ASW-applications.pdf

Doesn't sound like it.

But I see a need for something like that today. Especially if you can drop them from any sonobuoy tube or even from the RBOC chaff launchers. Just need to drive the cost down to roughly that of a sonobuoy. IM warhead to minimize stowage issues.

 

[Scott Kenny]

Does anyone here know if sonobuoys are stored in the magazine with the lightweight torpedoes, or somewhere else onboard ships?

Because if sonobuoys are stored in the magazine with the LWTs, then there's no additional costs for stowing a pallet of LCAWs in there, too, other than the physical space.

 

[TomS]

Does anyone here know if sonobuoys are stored in the magazine with the lightweight torpedoes, or somewhere else onboard ships?

Because if sonobuoys are stored in the magazine with the LWTs, then there's no additional costs for stowing a pallet of LCAWs in there, too, other than the physical space.

At least in the Spruance's and their relatives, the buoys are stored adjacent to the hangar, while torpedoes are down in the hull, adjacent to the Mk 32 tubes. There's a weapon elevator from the torpedo room up to the hangar, though, so it's an easy transfer (for reloading the surface tubes, you strip the parachute pack off the back of an air-launched torpedo). The older Burkes without hangars may have buoys in the torpedo magazine; I'm not sure.

But the current crop of miniature torpedoes are bigger than standard sonobuoys, 6.75-inch diameter and about 7 feet long. I assume they would live in the torpedo room/magazine on a surface ship, not with the buoys. (The ones temporarily deployed on carriers had dedicated launchers and apparently no reloads.)

I thought CRAW was supposed to fit in the external countermeasures tubes on certain subs, but that looks a bit too big in diameter.

 

[Scott Kenny]

Thank you!

At least in the Spruance's and their relatives, the buoys are stored adjacent to the hangar, while torpedoes are down in the hull, adjacent to the Mk 32 tubes. There's a weapon elevator from the torpedo room up to the hangar, though, so it's an easy transfer (for reloading the surface tubes, you strip the parachute pack off the back of an air-launched torpedo). The older Burkes without hangars may have buoys in the torpedo magazine; I'm not sure.

Okay, so it wouldn't be too hard to stuff a rack of buoy-sized torpedoes into the torpedo magazine on a ship. Make that LCAW rack the same footprint size as whatever the standard LWT packing is, and you'd lose all of one rack of LWTs in exchange for probably 4x the amount of LCAW.

Any LCAW-like mini torpedoes being fired from RBOC launchers can just be stuffed into the same lockers as the RBOC reloads. Or, if they're adding another set of launchers specifically for the LCAW, stuffed into the extra lockers added topside.

But the current crop of miniature torpedoes are bigger than standard sonobuoys, 6.75-inch diameter and about 7 feet long. I assume they would live in the torpedo room/magazine on a surface ship, not with the buoys. (The ones temporarily deployed on carriers had dedicated launchers and apparently no reloads.)

I thought CRAW was supposed to fit in the external countermeasures tubes on certain subs, but that looks a bit too big in diameter.

Yes, the CRAW is a fairly long beast. The Ohios physically have space for a larger diameter external countermeasure, though it looks like the CRAW is the same diameter as a current-standard ADC external. (I'm just confused because we called what the Ohios had in 2001 a 5" countermeasure. Maybe they did a size change after I got out?) And yes, also space for a 7ft long item, the externals are under the turtleback and there is a good 20ft laterally between sides, not counting the angle the external launchers are set to.

I never did serve on any fast-attacks, so I have no clue about any external CMs on 688s, Seawolf, or Virginias. Maybe stowed on the ends of the stabilizer plates? The other option would be inside the ballast tanks, which is an unpleasant option. Hard to access.

 

[publiusr]

What is the small torp aims for the rudder…no warhead….maybe entangling payload to foul things.

 

[Scott Kenny]

What is the small torp aims for the rudder…no warhead….maybe entangling payload to foul things.

On a sub, it's the shaft seals that are the worry. Pop those and you have stopped the sub.

 

[Voltzz]

On otvaga2004 someone uploaded a brochure for the Atlas Elektronik SeaPike LCAW. This just seems to be a later iteration of the STN LCAW proposal (STN-Atlas at some point rebranded to Atlas Elektronik), it even has the same configuration of seperate search and attack sonars. Unfortunatly the hosted images are gone now, and only the previews are still viewable. The resolution is bad but with a bit of squinting the text is still readable:

The LCA is a low cost but very effective ASW weapon against conventional single and double hull submarines. Especially designed for AS operations in difficult littoral and shallow waters. Owing to the small size and weight of the weapon the requirement for the launcher and system integration are low. The Search-While-Sink procedure without propulsion, small size and weight of the weapon, a shaped charge warhead are the principal reasons for the low cost solution.
The key technologies and fuctions have been already demonstrated by large scale trials.

Dimensions:

Effector:
Length less than 900 mm
Diameter less than 124 mm
Weight less than 20 kg

with Booster:
Length less than 2300 mm
Diameter less than 124 mm
Weight less than 43 kg

Weapon Configurations
The LCAW system is available in two configurations. The ballistic missile configuration is employed by rocket launch from naval platforms and the gravity released configuration can be dropped from aircraft.
The ship-launched configuration of LCAW SEAPIKE is stowed with folded wings in a sealed launch canister for protection against environmental influences and for ease of handling.
The configuration employed from aircraft consists of the underater weapon and the parachute only. It is stored in a logistic container for storage and transport.

SEAPIKE System for Naval Platforms
The launcher for the ship launched weapon is trainable in azimuth/elevation and stabilized for low pointing errors of the ballistic sollution.
The small dimensions and weight if the LCAW allows the storage of large amounts of weapons on board and a comfortable reloading of the launchers. Weapon integration into existing stabilized launchers. The interface to the Combat Direction System (CDS) can be adapted to all existing interface standards Via this interface all necessary threat, navigation and meteorological data, as well as control and display data, are exchanged.
The human interface can be a console in the Combat Information Centre (CIC) of the Platform.

SEAPIKE System for Aircraft
Platforms for the air-lauched weapon version are Maritime Patrol Aircraft (MPA) and Helicopters (HC). The Weapons, stored in container, will be carried on weapon carriers similar to a LWT. Each container stores (?) for a certain amount of weapons, for HC's the weapon carrier are located outside the fuselage. For MPAs the installation is inside the bomb bay. The weapon size would also permit a release through sonobuoy dispensers.
Due to the advantages of the LCAW in size and weight, compared to the LWT, more weapons can be carried on-board or the operating time of the aircraft can be increased (stores) are located outside of the fuselage. For MPAs the instalation is inside the bomb bay.
Compared to a Light Weight Torpedo (LWT), considerably more weapons cn be carried with the aircraft or the the endurance can be increased with the same number of weapons.

I might have made some mistakes with the transciption, but the weirdness in the last text is the same in the original.

 

[Voltzz]

Found a blurry picture of a SeaPike model in an article about DEFEXPO 2004, but unfortunately there is no additional information. At least it suggest that the program went on for longer than i had assumed, and overlapped with the SeaSpider anti-torpedo-torpedo shown in the same picture. Interesting that they did not try to give SeaPike anti-torpedo capabilities and instead went for a larger diameter (210mm VS 124mm) and rocket propelled anti-torpedo-torpedo. I would guess to allow for higher speed and a much larger warhead, so that near misses can still disable an attacking torpedo.

Edit: Confusingly, the picture also shows the torpedo payload without the ballistic cap depicted in my post above.
Edit 2: Found a higher quality image of a very similar expo display from IDEAS 2006. It shows the same three torpedoes and also solves the ballistic cap mystery: The SeaPike display model seems to have a detachable cap that can be seen (in white) on the left of the torpedo payload.

 

[lastdingo]

A larger diameter may also help with SONAR performance.

 

[Scott Kenny]

When it's launched out of a deck mortar, a larger tube is not particularly a show-stopper. Just add a cluster of say 3x 210mm tubes in addition to all the 5" tubes.