US Navy coughs $34.5m for hyper-kill railgun that DOESN'T self-destruct

Re: Revolutionise what?

It's been done. Japan and France have used them. The planes are tiny, and used folding wings to fit into the bay. They weren't used for combat, but reconnaissance. Obsoleted by improvements in radar and sonar tech.

Re: Revolutionise what?

if there was only naval warfare available, russia would be on the top with their supercavitating shkval torpedoes. how do you defend against 370km/h torpedo when yours only go 80km/h, it would be like shooting fish in a barrel :)

Re: Revolutionise what?

Good job we have the best subs

Re: Revolutionise what?

"no need for expensive and dangerous explosive projectiles"

Depends what the target is. A conventional shell with proximity fuse could destroy a target that you didn't hit - this is the likely scenario given the range, however with a railgun a soft-bodied target might simply be holed and without any significant mass to deliver the kinetic energy to it would be like a rifle-bullet hitting tissue paper unless it hit something heavy or vital.

Anyone know what the likely velocity is at ~300kms ??

Air friction and Battleships

Straightline flight of a railgun projectile at sea-level (well it is being fired from a ship) will result in a cloud of molten metal a couple of clicks from the railgun's muzzle. The projectile is already bloody hot from the millions of amps passed through it as it accelerates between the rails, the air friction from travelling at Mach 7 would finish the job. Even if by some miracle it did survive it would lose a lot of its velocity due to the aforementioned air friction so it would still take a lot more than 2 minutes to go 200 kilometres.

The battleship solution is to fire a shell from a gun in a high parabolic arc so most of its trajectory is in thin air and it will retain most of its initial speed and not melt or overheat on the way. That takes even longer to get to target, of course; a 15" shell from a British WWII battleship could take 90 seconds to cover 30 kilometres with a muzzle velocity of about 750 m/s, just over Mach 2. Firing railgun projectiles in the same high ballistic arc would double or triple their time-to-target.

Like battleship shells railgun projectiles don't have terminal guidance so with wind drift, irregularities in the firing system etc. the circular error at the target 200 km away would probably be a few hundred metres. If the target is a vehicle like a tank it may not even be in the same country when the projectile arrives. If the aim is to hit a stationary building or structure then it's rare that it has to be destroyed right now and a Tomahawk or two will do the job nicely -- see the Chinese Embassy in Belgrade in the recent past to show just how precise that sort of targetting can be done.

Railguns might, just might be useful for close-in defence of major warships, able to hit to a line-of-sight threat before it comes in too close but scaling them down to something the size of a Phalanx is not going to be easy.

Re: Cooling

I would imagine not - weapons tend to be designed in a modular fashion both for maintenance and the ability to retro-fit. The lifespan of a vessel (multi-decade) is much greater than the lifespan of its individual systems.

I therefore suspect that any design will have to be pretty self contained and not require extensive modifications to the platform its mounted on.

very few weapon systems are designed on the basis that you build the platform around them - the only one I can think of easily is ICBM nuke submarines.

Plus, I doubt you'd want to be using your hull as a heat sink (lovely big IR signature against a cold background)