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Subject: Cluster bolblets (via rockets) vs modern surface vessels
HeavyD    8/29/2012 2:43:26 PM
How would a modern, thin-skinned, electronics-laden ship fare if hit by dozens of cluster bomblets? A 277mm MLRS for example is loaded with 644 dual-purpose submunitions. It seems that radars, missile and torpedo tubes, SeaRAM and CWIS systems are all very vulnerable to even a relatively small munition. The Japanese learned in WWII that it was a bad idea for their cruisers to have LOX-powered Long John torpedoes on deck...even a strafing aircraft could set them off... Is this a vulnerability for US ships, or also an opportunity? Could a missile or gun-based CWIS system be overwhelmed and potentially suppressed with a hail of Starstreak-like darts (think 900 gram, 22mm flechettes with 450g of explosive and enough energy and sectional density to punch through 15mm - 25mm of armor) released 5km from the target?
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Reactive       8/30/2012 12:51:32 PM
There was a thread about this once before as I recall, the problem you have is that you still need to get the submunitions close enough to the ship in order for them to have a chance of a hit, you can't release them 5km away as there'll be no terminal guidance (Starstreak HVM uses laser beam-riding).  
If each submunition features terminal IR guidance  then you could have a way of placing a heavy burden on interceptor missiles (the best concept analogue to this was the cancelled MLRS MGM-164 ATacMS Blk2 (Brilliant Anti Tank (BAT) munitions) which featured >10 guided submunitions deployed from the main rocket with terminal guidance for anti-armour roles. If the main missile featured a MAW receiver (to detect AMM's) that triggered separation of submunitions then in theory you could sequentially stress the medium ranged defensive systems (SM/ASTER etc) (by reducing range/time for intercept) especially if one target suddenly becomes 10. Whether that would be enough to get through short-ranged interceptors and CIWS like Sea-Ram (that can ripple-fire) and Phalanx is open to debate.
The other possibly viable solution (assuming target data was adequate which is a very big if) would be to use a ballistic trajectory and separation at at high speed for the main missile and then deploy a few hundred dart-like submunitions (with simple IR guidance) and hope that they manage to penetrate by weight of numbers to hit the vulnerable elements of the superstructure (via pattern recognition), this is much the same system, but in a different context as the CBU-97/BLU-108 submunition. The problem is that shipborne defenses are very good at selectively prioritising and targeting the greatest threat so guidance would have to be exceptional at every stage of the process to give you a good likelihood of your darts being on target.
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Reactive       8/30/2012 12:58:36 PM
Sorry, should just say, the biggest problem for either of these systems is that if you go for many interceptors then you are relying on relatively poor terminal guidance, the greater the range between deployment of submunitions and the target the less chance they have of getting close to it (your main container missile has to also be dead-on-target), all of which has to happen in a hellish EW environment with jamming and countermeasures and several layers of interceptors. The basic premise of forcing your enemy to target multiple targets is certainly strong - whether or not you would simply end up with submunitions that owing to their sensors cost virtually the same as a typical ASHM is another matter, and I don't really know how you would ever get those to be capable of bridging the distances necessary after the first AMM interception point, one possibility might be that the submunitions are able to pool targeting data to keep them on a viable track, another might be that an offboard system provides guidance.
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HeavyD       9/1/2012 12:07:43 AM
Yes the terminal guidance is the issue, with several potential solutions.
Real Starstreak darts are guided as they are designed for relatively small and maneuvering targets like helicopters.  By comparison ships are huge and slow.  A carrier missile traveling at Mach 2.5 = 1000 meters per second.  Releasing un-guided darts (oversized 1 kg flechettes) from even 8km out would hit the target 10 seconds later - not nearly enough time for even a small ship to avoid the bulk of such 'darts'.
For release that far from the target each submunition would need to be a rocket - a 70mm hydra has a 700m/sec speed and a 8km range.  Each weighs approx. 23 lbs with a 10 lb warhead or 30 with a 17 lb warhead.  We're now talking about essentially putting a 19 shot Hydra launcher (approx. 600 lbs with 17 lb-ers) as the warhead on a cruise missile that locks-in on the target and launches it's rockets when within range or senses an intercept.
How lethal would 6-10 hydras that got through the missile or gun-based CWIS be?  Depends on what they hit, right?  I'd design the missile to be smart and/or programmable such that it could attack from different aspects.  For example a stern-attack could be very effective on ships with helicopter hangers aft.  Might even hit the helicopter.
Also the first missile in could carry HARMs - locking in on the CWIS system.  Or decoys to deplete SeaRAM systems that have relatively small capacities enabling follow-on attacks with heavy warheads to be successful. 
This is what scares me about a SeaRAM system.  Great for picking off one-sy two-sey attacks but clearly not designed for 20 simultaneous in-bounds...
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Reactive       9/2/2012 11:44:34 AM
The launch platform has have targeting data for the ship/s, this in itself has tended to result in ASHM's optimised for the useful ranges at which this data can be supplied.
Most anti ship missiles stay as low as they possibly can (sea-skimming) to close the anti-missile engagement envelope as much as possible - a powerful radar array like the AN/SPY-1 or SAMPSON will detect the missile the moment it climbs above the horizon.
 The AN/SPY-1 is mounted at a height of 50' giving it a horizon of ~14 KM, it seems to me that the best profile for a carrier missile would be akin to the Klub, subsonic cruise @ <15m altitude with a terminal  supersonic climbing phase to deploy IR-guided submunitions @ mach 3+ (plausible since the carrier doesn't have to survive the journey).
The homing submunitions wouldn't necessarily need to be rocket-assisted at these ranges (release @ ~10km) and would have a shallow enough trajectory to be able to stay under the cloud base. As you say, IR pattern recognition can prioritise targets (bridge/radar/launchers/CIWS) and if they can communicate it's also plausible they can prioritise as a group. 
It's an intriguing idea, I'm sure as with most intriguing ideas there's a reason that it's impractical, perhaps someone will enlighten us. I think before starstreak HVM the idea of small supersonic guided darts would sound extremely outlandish, we also know from other systems (especially BLU-108) that IR homing/laser fusing and pattern recognition are affordable enough to use in a submunition. 
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