Original URL: http://www.theregister.co.uk/2010/12/15/blitzer_trials/

'Blitzer' railgun already 'tactically relevant', boasts maker

US Navy preps flyswatter for Muscovite 'Mosquito'

By Lewis Page

Posted in Science, 15th December 2010 14:02 GMT

It's all go in the world of hypervelocity railguns this week. Following Friday's 33-megajoule test shot carried out at a US Navy laboratory, it has also been announced that a different railgun known as "Blitzer" has recently carried out firings which suggest that it is almost combat ready.

The Blitzer comes to us courtesy of famous radical-tech company General Atomics, well known to Reg readers for its development of robot warplanes and electromagnetic mass-driver catapults for aircraft carriers among other things.

Now, in a statement which is dated 7 December (but which didn't appear on the firm's website until yesterday*) General Atomics would like to inform the world that the Blitzer was carrying out highly interesting and "tactically relevant" shoots back in September, actually, while the johnny-come-lately test job at Naval Surface Warfare Centre Dahlgren hadn't even got its boots on.

The Dahlgren railgun shot was a stepping stone towards projectiles launched at Mach 7+ with muzzle energies of 64 megajoules, which would (once weaponised) be able to fly 200 miles and hit their targets still going at Mach 5. Such long-range over the horizon bombardment is one of the stated aspirations of the US Navy's railgun project: but the test guns at Dahlgren are not weapons and their projectiles are not yet designed to fly through the air for any distance - they are focused on movement along the launching rails, from which they emerge at Mach 7.5.

Blitzer, however, is less about ultimate velocity and muzzle energy and more about proving a viable weapon. Its projectiles fly at only Mach 5: but they are much more advanced towards being actual munitions. In the Blitzer, the armature which moves along the rails and carries the driving current between them is merely a "sabot" which propels the actual projectile to launch speed and then falls off shortly after clearing the muzzle - rather as in the case of modern armour piercing tank ammo, which consists of a fin-stabilised penetrator dart which rides down the cannon barrel on discarding sabots.

According to the new GA statement:

This test demonstrated the integration and capabilities of a tactically relevant EM railgun launcher, pulsed power system, and projectile... The projectiles were launched by the Blitzer system at Mach 5 speed with acceleration levels exceeding 60,000 gee, and exhibited repeatable sabot separation and stable flight.

Blitzer will provide leap-ahead multi-mission capability in both naval and land-based applications. Using one weapons system, it provides defensive capability against a number of advanced air and surface threats and delivers strike capability against land- and sea-based targets. With demonstrated muzzle velocities greater than twice that of conventional gun systems, Blitzer provides a dramatic increase in standoff and lethality at lower cost, without the need for propellants or high explosives.

Apart from long-range bombardment of surface targets, another application seen for railguns is naval anti-aircraft work. At the moment, aircraft and ship-killing missiles present a terrible menace to naval forces: a sea-skimming aircraft or missile can appear above the horizon just twenty miles off. In the case of a supersonic missile, this leaves only a very short time for a warship to do anything about it.

Swatting the Russian Moskito

Supposedly the very latest missile systems may be able to launch an interceptor rocket, accelerate it to the necessary Mach 4+ speeds very fast, and so manage to knock down such menaces as the Klub or Moskit ("mosquito"): but there's a lot of doubt about whether this would actually work - and there's no doubt at all about the crippling cost of such defensive kit and the limited number of counter-missiles a ship can fire before its tubes are empty.

But, as General Atomics has previously noted:

In the case of ship defense, the launch package can reach the horizon in seconds.  This allows for engagement of threats much quicker and farther away than current systems, having the ability to replace multiple systems in the current layered defense approach, with the potential for reduction in the cost to defeat multiple threats by several orders of magnitude, and with a much deeper magazine than alternative approaches.

Certainly a railgun slug from the Blitzer, accelerating down the rails at 60,000G, is travelling at Mach 5 far sooner than an Aster can reach its top speed of Mach 4.5. The projectile could reach out and touch an inbound Vampire** much more quickly: a Blitzer-derived weapon would probably get more chances to score a hit than the Royal Navy's PAAMS/Sea Viper or the USN's Aegis warships would, and would have many more rounds to shoot. Asters and SM-2s have the advantage of being guided and more likely to make a hit, but the Blitzer's projectiles are already finned - it would be comparatively easy to make them smart, though the railgun would need to be aimed reasonably accurately to begin with.

In the nearish future, depending how accurate GA's "tactically relevant" puffery turns out to be, warships equipped with Blitzer-type railgun turrets might offer far better air defences than Type 45 or Aegis vessels can today. Such defences might only be penetrable by bigger, heavier railguns firing from beyond the horizon - along the lines of the Dahlgren boffins' desired 64-megajoule weapon. It would, of course, require a massive capital ship to carry such guns and power them for any serious rate of fire - such a future might see the big-gun (railgun) dreadnought battleship return to its lost dominion over the seas, ousting the parvenu aircraft carrier, missile cruiser etc.

General Atomics may not be the firm building the weapons, however. The US Office of Naval Research, in charge of the railgun effort, has previously commissioned GA for a lot of the work - indeed the Blitzer was developed for the ONR. However the next ONR railgun, expected to open fire at Dahlgren next year, is to be built by the North American acquisitions of BAE Systems plc. ®

Bootnote

*The Google cache at the time of writing confirms that it wasn't up as of the 12th, certainly. As you can imagine, we here on the Reg crazy weapons desk check General Atomics' press page daily.

**The NATO brevity code word for "hostile anti-ship missile", which would take a bit too long to say on a voice circuit during an air attack.