"Navy Considering Railgun for Third Zumwalt Destroyer" Topic

Engineering studies to include an electromagnetic railgun on a Zumwalt-class destroyer (DDG-1000) have started at Naval Sea Systems Command, NAVSEA's head said Thursday.

The work will do the math to determine if the Zumwalt-class will have the space, power and cooling to field a railgun – likely replacing one of the two 155mm BAE Advanced Gun Systems (AGS) ahead of the ship's deck house, Vice Adm. William Hilarides told USNI News following remarks at the Office of Naval Research Naval Future Force Science and Technology Expo.

"We have begun real studies – as opposed to just a bunch of guys sitting around – real engineering studies are being done to make sure it's possible," Vice Adm. William Hilarides said…

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Is this military PR and media hype?

The Zumwalts were always designed with the capability to field railgun technology. It isn't space requirements, it's the massive electricity output of the ship's engines to operate the railgun. These engines were part of the original design.

Only interesting bit of news is the announcement that it will be ready by 2018, one year earlier than originally announced.

I absolutely love that last line …

"We have begun real studies – as opposed to just a bunch of guys sitting around – real engineering studies are being done to make sure it's possible," Vice Adm. William Hilarides said…

I guess the previous reports acme from "just a bunch of guys sitting around".

I guess we should believe him now?

Dan

Maybe it's different now that they have an operational railgun.

Operational railgun in the power class they wanted, to be pedantic.

I'm honestly amazed that any conventional propulsion rig can generate enough electricity to feed the railgun and move the ship at battle speeds simultaneously.

Zumwalt power system and why it's different.

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Hmmm, we built a whole aircraft around a weapon (A-10 Warthog), but navy planners don't think to do something similar.

Rather shockingly poor planning on a far more expensive system, I'd say.

Mako, don't get what you mean.

The Zumwalt was designed from the bottom up to be a weapons carrier for a railgun. It is built with 4 of the biggest gas turbines available, capable of generating 80 megawatts. That's enough to fire the gun, run ship systems and generate propulsion.

That admiral is blowing smoke for some reason.

Ah, I see.

I was taking the admiral literally, and know the Zumwalt design is being put into production, so figured they'd screwed up, as usual, and not properly designed the vessel to accommodate the new weaponry.

Thanks for the clarification.

Good to know billions may have perhaps not been wasted on this, afterall, assuming the ship doesn't turn turtle due to its bow design, in heavy, following seas.

"The Navy's been talking about using railguns for the past ten years. The Office of Naval Research launched a prototype program in 2005, with an initial investment of $250 USD million committed through 2011. The Navy anticipates spending about that much more by 2017.

Its latest weapon is an electromagnetic railgun launcher. It uses a form of electromagnetic energy known as the Lorentz force to hurl a 23-pound projectile at speeds exceeding Mach 7.

The Navy likes the weapon for several reasons, not the least of which it has a range of 100 miles and doesn't require explosive warheads. That makes it far safer for sailors, and cheaper for taxpayers. According to the Navy, each 18-inch projectile costs about $25,000 USD, compared to $500,000 USD to $1.5 USD million for conventional missiles."

It seems that the first two designs were test beds for developing technologies. The third design is the first one they are considering using the railgun on.

Curious, however, if the concept was a platform designed with the primary purpose of carrying the railgun is the statement:

"…The inclusion of the railgun does mean a capabilities trade for the ship… It's physics. Without taking something off, you're not putting on a many ton system, so a gun would be a logical thing to take off and put the railgun in its place."

So it would appear that the ship design is currently based on a conventional weapon design, but they are hoping to exchange one conventional gun with a railgun, if they can keep the weight or power exchange feasible.

Obviously the conventional gun(s) will need to be replaced. The AGS 155mm naval gun is an advancement to prior gun systems, but it is an interim system if the railgun is installed.

Why keep a traditional gun, its shells, and the water ballast tanks necessary for recoil, when you can install a replacement with 20% more range, equal or better accuracy, more destructive capability, cheaper ammo cost, safer to operate, and demonstrate higher technology to enemies?

Like I've been saying, the Zumwalt was designed with and already equipped with massive engines meant to power a railgun. No need for excess energy if the Zumwalt was only meant to fire convention chemical guns.

Presumably it is only the sabot that is being magnetically accelerated to 5000mph?

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If it is magnetic acceleration, what's the large chemical explosion on firing?

Don't think the explosion is chemical but likely plasma from the energy used ionising some of sabot. In one of the video you can see a flash at gun breach.

When USA was developing coil guns for the starwars program the gun was designed to ionise a disk of metal at bottom of projectile & the magnet field would use that to pull projectile along barrel.

Ah, from Popular Science: link

"The flames [at the muzzle on firing] are from pieces of the projectile disintegrating; the 7-pound slug is jammed so firmly between the rails that when it's fired, pieces shear off and ignite in the air.

There's been some speculation online that the flames come from some sort of gas that's been used to increase conductivity. Wrong: The EMRG uses no secondary propellant — just electricity. As a result, the breech can remain open during firing and the gun produces no blowback whatsoever.

In fact, the researchers sometimes place cameras and mirrors inside the breech during tests to get a better sense of what's going on."

There's also the fact that the shockwave from the highly un-aerodynamic slugs the Navy was using in tests shatters air molecules into plasma, just like a re-entering spaceship. So you get a huge muzzle flash that the slug "punches through" as it rapidly slows down due to drag.