General Atomic says its Blitzer rail gun already "tactically relevant"

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 rail guns 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.

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 Page note that there is doubt about whether this would actually work — and there is no doubt about the crippling cost of such defensive kit and the limited number of counter-missiles a ship can fire before its tubes are empty.

As General Atomics has previously noted:, however,

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.

A rail gun slug from the Blitzer, accelerating down the rails at 60,000G, is traveling 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 (NATO code word for “hostile anti-ship missile”) 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 U.S. Navy’s Aegis warships would, and would have many more rounds to shoot.

Page adds that 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 rail gun would need to be aimed reasonably accurately to begin with.

In the near future, depending how accurate GA’s “tactically relevant” statement turns out to be, warships equipped with Blitzer-type rail gun turrets might offer far better air defenses than Type 45 or Aegis vessels can today. Such defenses might only be penetrable by bigger, heavier rail guns firing from beyond the horizon — along the lines of the Dahlgren researchers’ 64-megajoule weapon. It would require a massive capital ship to carry such guns and power them for any serious rate of fire — which means that the future may see the big-gun (rail gun) dreadnought battleship return to dominate the seas, replacing the late-arriving aircraft carrier, missile cruiser, etc.

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