Navy to test-fire railgun

[Werner]

It's also moving Mach 10 or so, which means there is precious little time to calculate a firing solution and shoot an interceptor.

These speeds are not inconvenient if you're shooting down an ICBM 2,000 miles away. Not so much if the warhead is first detected crossing the visible horizon.

[Werner]

Well, yes, I guess I did miss the fine print. Thanks, Timmy.

I must say though that the plasma seems to leave a LOT of heat signature for counterbattery to sensor on...

A single IR sensor can't detect the range, only the bearing and elevation, so it can't determine the actual trajectory. To determine the trajectory you will need a radar to locate the round in 3 dimensions. Well, an advantage of plasma is it would shield the round against some radar.

http://www.nationaldefensemagazine.org/ ... icGuns.htm

I think you missed a few zeroes. According to the article, a 64 megajoule gun requires 120 megajoules at 50% efficiency and 6 million amps, or 40 gigawatts. In comparison, Chicago's total power output is 19 gigawatts of power.

[chuck]

You are confusing energy with power. 64 Megajoules is a measure of energy. 40 gigawatts is a measure of power. Energy is power integrated over time. Like a normal gun, a railgun delivers high peak power, but sustains that peak power for only a tiny length of time, so the power is high but the total energy delivered is really quite modest. Have an hour to deliver 64 MJ, and you only need to deliver it at a rate of about 17 Kilowatts. Have a nanosecond in which to deliver 64 MJ, and you will need to deliver it at a rate of about 6 quadrillion watts.

In fact the total energy, 64MJ, delivered by a rail gun is 1 order of magnitude less than the energy delivered by a WWII era 16" gun. The peak power delivered by the rail gun is roughly comparable to those developed by a 16" naval gun. If you accumulate all the energy generated by running Chicago's 19GWs of generators for 1 hour, you can fire that rail gun over 1 million times.

[Lesforan]

Let's pause a moment from contemplating the railgun (and here I thought a railgun was one of those massive cannons mounted on a flatcar) to consider what type of platform could be used for its deployment. How about an armoured ship of about 45,000T? The railguns could be mounted in triple turrets, fed from magazines deep below decks. Of course, the ship would require secondary and anti-aircraft armament. Wait! Wait! We have just reinvented the battleship!

[Timmy C]

That's what I've always wished for, Les. Smaller railguns would be somewhat sufficient for AA purposes, since they travel so fast. You'd just need a different guidance system for the AA shells.

[chuck]

Even the developers of rail guns admits a practical rail gun that is capable of justifying replacing a conventional weapon is really a long shot.

[Lesforan]

That's right, Timmy. Just be sure to have plenty of heavy-duty fuses on hand, and hope you don't lose electrical power during a battle.

[Haijun watcher]

The latest on the USN railgun:

Defense News

US Navy Keeps Electromagnetic Cannon in Its Sights

WASHINGTON � The US Navy is quietly pushing ahead with a radical new cannon that one day could transform how wars are fought, even though some Pentagon officials have voiced concerns over its cost and viability.

Named the railgun, the weapon in question represents a paradigm shift in ballistic technology. Instead of using gunpowder and explosive charges to shoot a shell from its barrel, it employs vast amounts of electromagnetic energy to zoom a projectile along a set of copper-alloy rails.

Thanks to four small fins on its rear, the hefty round can then be guided toward a moving object � such as an enemy ship, drone or incoming ballistic missile � relying purely on the kinetic energy from its vast momentum to destroy the target.

(...SNIPPED)

[oneslim]

Report to Congress

https://news.usni.org/2016/06/27/docume ... ae886b0afd

Bob W

[Haijun watcher]

Popular Mechanics

Watch the Navy's Railgun Fire From Every Angle

The railgun takes the first shot of its commissioning series.


By Eric Limer
Mar 21, 2017

The Navy ushered in the railgun future way back in 2012 with the first shots of its electromagnetic cannon. But although the concept has been proven and the cannon is functional, its road to deployment has been a bit rocky. Between enormous energy requirements, and non-explosive shells that offer limited in-air guidance, electromagnetic weapons are proving a bit unpractical compared to some of the conventional alternatives. At least for now.

But that hasn't stopped the Navy from pressing on with the research, and this recently released video of a test fire from November 2016 shows cannon just blasting away with astonishing ferocity, and from any angle you could ever want:

The railgun was originally scheduled for testing at sea on the USNS Trenton this year, but that seems to have been delayed until 2017 at the earliest. Meanwhile, the USS Zumwalt�which boasts the robust power plant necessary to actually take one of these weapons into service�is having some trouble with its conventional guns and their wildly expensive ammo. Only time will tell if the two will actually pair up any time in the near future, but in the meantime it sure is clear that the electromagnetic cannon isn't kidding around.

(...SNIPPED)

[Admiral John Byng]

Doesn't anyone have a calendar at PM?

"The railgun was originally scheduled for testing at sea on the USNS Trenton this year, but that seems to have been delayed until 2017 at the earliest."

[Haijun watcher]

An update on the ammo such rail guns would use:

Scout.com

Navy to Fire Rail Gun Hypervelocity Projectile From 5-inch Guns
Scout Warrior
Yesterday at 8:38 PM

By Kris Osborn

The Navy plans to fire a high-speed, long-range rail-gun Hypervelocity Projectile from its deck-mounted 5-inch guns to destroy enemy drones, ships, incoming missiles and even submarines, service officials said.

The effort is led by a special Future Naval Capability program.

�The program is leveraging commercial electronics miniaturization and computational performance increases to develop a common guided projectile for use in current 5 inch guns and future high velocity gun systems. The HVP effort will seek to increase range and accuracy of the 5-Inch Gun Weapon System in support of multiple mission areas,� Navy spokeswoman Lt. Lauren Chatmas told Scout Warrior.

(...SNIPPED)

[Haijun watcher]

Alert 5

Railgun fires multi-shot salvos

The U.S. Navy�s electromagnetic railgun has successfully demonstrated the capability of firing multiple salvos.

[Haijun watcher]

Bad news for USN rail gun fans:


Defense News

US Navy ditches futuristic railgun, eyes hypersonic missiles
By: David Sharp, The Associated Press ? 3 days ago
In July 2017, the Office of Naval Research announced that the Navy's electromagnetic railgun was ready for field demonstrations.
BATH, Maine � The U.S. Navy has pulled the plug, for now, on a futuristic weapon that fires projectiles at up to seven times the speed of sound using electricity.
The Navy spent more than a decade developing the electromagnetic railgun and once considered putting them on the new, stealthy Zumwalt-class destroyers built at Maine�s Bath Iron Works.
But the Defense Department is turning its attention to hypersonic missiles to keep up with China and Russia, and the Navy cut funding for railgun research from its latest budget proposal.
�The railgun is, for the moment, dead,� said Matthew Caris, a defense analyst at consultancy Avascent Group.
The removal of funding suggests the Navy saw both challenges in implementing the technology as well as shortcomings in the projectiles� range compared to hypersonic missiles, he said.
The Navy�s decision to pause research at year�s end frees up resources for hypersonic missiles, directed-energy systems (like lasers) and electronic warfare systems, said Lt. Courtney Callaghan, a Navy spokesperson. Information gleaned during testing will be retained in the event the Office of Naval Research wants to pick up where it left off in the future, she added.
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