Faced with the threat from swarms of small boats. the US Navy is looking to equip the sensor turrets of its shipborne helicopters with the ability to designate multiple targets for simultaneous attack by laser-guided missiles like Hellfire.
Photo: US Navy
A new Office of Naval Research project, called Multi-Target Track and Terminate (MT3), aims to demonstrate a prototype multi-target laser designator on an MH-60 - including at least six simultaneous launches against maritime targets in realistic conditions - within 60 months of contract award. It's not as easy a task as it sounds.
According to ONR the inshore threat to Navy ships ranges from tens of RPG-armed raiders on jet skis to a handful of fast attack boats carrying short-range cruise missiles. A helicopter launched to defend the ship - whether a manned MH-60 or AH-1 or unmanned Fire Scout - must be able to spot the threat among other boats in the area, pick the most threatening, and rapidly engage them. The Navy does not want a repeat of the 2000 suicide attack on the USS Cole in Aden.
Photo: US Navy via Wikipedia
The way ONR sees it working, a wide field-of-regard MTI radar or mid-wave IR would cue the narrow field-of-view EO/IR sensor for tracking, identification and prioritization of each target. Six or more boats would then be designated, each with a different pulse code, the laser revisiting each up to 20 times a second to illuminate them for incoming semi-active laser-guided weapons.
There's not much information available on multi-target laser designators. Physical Optics has been working with Navy funding on a ship-mounted system using holographic telescopic optics to provide beam steering. And Boulder Nonlinear Systems is developing a multi-spot laser beam steering system using a liquid-crystal spatial light modulator. But do I know what any of that means? Of course not.
rapid-fire 40mm cannons will give anyone a bad day, just need to be matched with a good targetting system
From that, the crazies out there would more than likely attempt a suicide mission on a ship they were set on sinking by sailing a boat filled with explosives straight at the target vessel. Either scenario, as irtusk states, would be better handled by on-board systems like a Bushmaster or a 20/25mm gatling for the ships approaching, and, once a line is crossed,an on-board hellfire system for when it's obvious to the ships' commander that the attacking vessel(s) is/are on a one-way mission.
RIM-116 Cost: $444,000/unit (Block 1) R: 7.5km Launcher weight: 5,777 kg, can hold 21rd
Speed: Mach 2
Hellfire Cost (AGM-114K): $65,000 R: 8km
Launcher weight (modified SeaProtector): 135kg, can hold 2rd
Speed: Mach 1.3
Hydra-70 (unguided) Cost: $1-4,000
(APKWS II) Cost: ~$10-20,000
R: 5-12km (surface-surface)
Launcher (modified SeaProtector): can hold 2x7 or 2x19. 4-8kg/rocket.
7rd, 91-136kg per launcher, loaded, 16kg empty.
19rd, 227-272kg per, loaded, 37kg empty.
Speed: Mach 1.8-3
Warheads: HE, flechette.
RIM-116 Cost: $444,000/unit (Block 1) R: 7.5km Launcher weight: 5,777 kg, can hold 21rd
Speed: Mach 2
Hellfire Cost (AGM-114K): $65,000 R: 8km
Launcher weight (modified SeaProtector): 135kg, can hold 2rd
Speed: Mach 1.3
Hydra-70 (unguided) Cost: $1-4,000
(APKWS II) Cost: ~$10-20,000
R: 5-12km (surface-surface)
Launcher (modified SeaProtector): can hold 2x7 or 2x19. 4-8kg/rocket.
7rd, 91-136kg per launcher, loaded, 16kg empty.
19rd, 227-272kg per, loaded, 37kg empty.
Speed: Mach 1.8-3
Warheads: HE, flechette.
CBD - thanks for your interesting quick check data provided and thoughtful comparisons..
Some minor technical issues could be questioned as to what would the actual 'sea-launched' range be for both a guided Sea-launched Hellfire and especially SL-Hydra (as compared to the assumed air-launched ranges noted?)
Also, the costs of a future USN sea-launched Hellfire variant (perhaps w/ blast frag or even the thermobaric head instead of the standard anti-tank charge) would be more than the avg 1990-2007 AGM-114K production costs noted? (I'll agree though, that the SL Hellfire should be cheaper per round than RAM HAS).
And perhaps a layered, redundant HAS-block RAM and SL Hellfire counter-small-boat defense would be optimal, especially given the dual targeting modes for greater PK?
Still prefer the rightously popular Oto Melara 76mm SR; very effective against both air, land and (small) sea targets. It also allows you to give a very impressive warning shot. The five inchers are just too big, slow and cumbersome for use against Boghammers/fast craft.
However, for REALLY impressive warning shots I would rely on the Dutch Goalkeeper 30mm gatling gun (has radar and EO/IR surface attack capability), it makes the Phalanx look like a BB gun.
While ranges for 70mm rockets vary greatly, ancient surface-launched versions have maximal ranges reported between 6 and 12km based on variants (some forces use it as a mini-MLRS system, like the USN landing craft in WWII, so those ranges may be ballistic). The US Hydra-70 system claims about 8, but that seems to be based on the short rocket motor (there are several variants of the warhead, motor, and fuse that can be rapidly swapped out) and 10km does not seem out of the question. The various guided versions in development (APKWS II, LOGIR, LGR, DAGR, etc.) should be soon at a stage where a 'shoot off' competition is possible. A laser-lock guidance is used for most of these guided rockets.
As far as the Hellfire goes, the M (Blast-Frag) and K (Anti-Armor shaped tandem charge) warhead variants of the Hellfire II are the prime candidates for this type of work, both have Semi-Active Laser homing and can be guided by a second party (ie, spotters ashore or UAVs). The M-variant warhead has been optimized for sea targets and is based on the K model, which has a 9000m air launched range and are claimed to have an 8000m surface(sea)-launched range in LOAL mode. A 2004 variant of the M-model was developed by LM as part of their "Interim Small-Ship Self-Defense System" (until SeaRAM could come on-line) that claimed a range of 9km (5nm).
As far as firing it from ships the Norwegians have launched an RBS-17 (Hellfire variant) from a modified Protector RWS based on a small boat (CB90 aka the future Riverine Combat Boat). Israel, Taiwan, Turkey, the UAE, Norway and Sweden are reported to use the naval variants (M and RBS-17, or a K-variant with anti-ship warhead) either from ships or helicopters. The Japanese MSDF has reportedly ordered some M-variants for testing (c. 2001).
Costs are a question. The variants offered for some foreign sales have cost in the $70,000 range and Taiwan's 2005 purchase of 400 had an average unit price of $125,000, but that includes a lot of support options (and inflation) beyond what USN forces would pay and the M-variant. Since it is a K-variant with a different warhead and other minor tweaks, the price shouldn't be that large for a decently-large buy.
A layered defense would be the most-likely operational deployment. A ship-based RWS with either Hellfire missiles or the guided 70mm (mini-Hellfire) rockets would provide a means of eliminating swarming small craft, saving the limited RAMs for higher-end threats (ASCMs).
Marcase,
Loss of Lock controls have been included on Hellfires since 1989 and 1991 (different levels of sophistication), so temporary loss of the lock is not a big deal. Placing the electro-optics package high on the ship (ie, on the mast) eliminates some of the problems of placing such a system near the water level.
The 76mm SR is great as a gun and both it and the 57mm guns used by the USN are fine for this role, but its hard to add a large, very heavy gun system to existing ships (the same goes for the Goalkeeper, though the USN will never buy it, since it already uses the 20mm Phalanx and has tested a version of the 35mm Millennium Gun). Adding a Remote Weapons Station or other system that involves minimal/no deck penetration (the millennium gun was tested for this reason) is much easier to accomplish, especially on short notice.