rail gun video

[cassandra and sara's daddy]

oh dear
http://blogs.fredericksburg.com/tenhut/2012/02/28/fire-the-operative-word-in-this-latest-railgun-test-video/

bet that will leave a mark

[MillCreek]

Ooooh!

[AJ Dual]

Both customers of mine.

Makes what I do for them in a very removed third-hand sort of way seem a teeny bit more exciting.

[Fly320s]

What caused the fire?

[Nick1911]

What caused the fire?

A guess?  Molten metal arcing off.  Maybe ionized air (plasma) resulting from the arc.  Assuming this is a true "rail gun", and not a coil gun.

[Ben]

We need to acquire one after we buy and populate APStown.

[Viking]

What caused the fire?

Overdose of Awesome.
I like that thing. Bit too big to conceal carry it though. When are they releasing the compact version? Will it have the shoulder thing that goes up and a gonkulator? Most importantly, will this railgun have accessory rails?

[freakazoid]

Our class never got to take a tour of the place, You could here it on base when it went off though. Pretty cool stuff.

[AJ Dual]

A guess?  Molten metal arcing off.  Maybe ionized air (plasma) resulting from the arc.  Assuming this is a true "rail gun", and not a coil gun.

[birdman]

What caused the fire?

Hot air.

The projectile takes roughly 100 liters of air and shock compresses it as it travels down the barrel, heating it substantially, the air becomes incandescent as it leaves.

It is a true railgun, not a coil-gun.

The plasma is too hot to be visible, the "fire" is just plain old hot air :)

[MechAg94]

Was the projectile wobbling before or after it went through the target? 

[AJ Dual]

Was the projectile wobbling before or after it went through the target? 

I was trying to figure that out too.

The projectile/armature looks like it's just a test payload and not too aerodynamic Hard to say, but it looks like it might be yawing a bit. I think in a deployable system, the armature that bridges the rails would be a two piece sabot that falls away, with a dart similar to an APDS in the center.

[Strings]

>The plasma is too hot to be visible, the "fire" is just plain old hot air<

Wait... they loaded it with Fistful?

[230RN]

I'm gonna start buying me some big-assed capacitors.

[birdman]

I'm gonna start buying me some big-assed capacitors.

Better off with a compulsator...for low impedance loads like a railgun, it's a better (and cheaper/more effective) match...see the Texas center for electromagnetics web page to learn more.

A vacuum core superconducting inductor is actually the best choice, but opening switches are an issue....(a new version of which I am in the process of patenting)

[Perd Hapley]

>The plasma is too hot to be visible, the "fire" is just plain old hot air<

Wait... they loaded it with Fistful?

How else do you get an:

Overdose of Awesome.

[AJ Dual]

Better off with a compulsator...for low impedance loads like a railgun, it's a better (and cheaper/more effective) match...see the Texas center for electromagnetics web page to learn more.

A vacuum core superconducting inductor is actually the best choice, but opening switches are an issue....(a new version of which I am in the process of patenting)

Seems to me that while compacting the power supply and handling of the electricity is a "very good thing" for railgun applications, the first applications are going to be naval vessels where space and power limitations are lessened somewhat.

I'm wondering where they stand in terms of disintegration/ablation of the rails themselves.

[birdman]

Seems to me that while compacting the power supply and handling of the electricity is a "very good thing" for railgun applications, the first applications are going to be naval vessels where space and power limitations are lessened somewhat.

I'm wondering where they stand in terms of disintegration/ablation of the rails themselves.

Rail life is still a major issue...but I'm in the process of finalizing a design that deals with that as well.

The issue of power is still an issue on a ship, even with a future "all electric" ship--that railgun needs peak powers in the 10-20GW range (or higher), or 200-400x what an all-electric destroyer could output in steady-state (and 50-100x what a carrier could do).

The main idea with a compulsator would be to have it mechanically driven off the same shaft as the main generator (gas turbine generator normally used to power propulsion motors)--allowing energy storage and peaking generation in the same device.

Brings new meaning to "divert power to weapon systems"...now all we need are shields!

[Fitz]

I knew when i read the thread title that birdman would end up in here.

Hey birdman... when we gonna get together for beers and consumption of seared meat?

Wifey and I were just talking recently about missing our breakfasts.

[AJ Dual]

Rail life is still a major issue...but I'm in the process of finalizing a design that deals with that as well.

The issue of power is still an issue on a ship, even with a future "all electric" ship--that railgun needs peak powers in the 10-20GW range (or higher), or 200-400x what an all-electric destroyer could output in steady-state (and 50-100x what a carrier could do).

The main idea with a compulsator would be to have it mechanically driven off the same shaft as the main generator (gas turbine generator normally used to power propulsion motors)--allowing energy storage and peaking generation in the same device.

Brings new meaning to "divert power to weapon systems"...now all we need are shields!

I'm wondering if twin counter-rotating sets of rails, arrayed like two side-by side Gatling guns, and the two aligned rails firing, then rotating out of the way would work to distribute wear on the rails, just like a traditional Gatling gun distributes wear and heat on it's barrels. There's  nothing about a railgun that requires the rails be enclosed in a "barrel", other than structural, to contain the extreme forces.

Although I'd think such a system is probably too complex, heavy, and costly to be worth it.

[230RN]

A vacuum core superconducting inductor is actually the best choice, but opening switches are an issue....(a new version of which I am in the process of patenting).

Do you mean closing the switches?  Or opening them as the missile passes given points in the fields?

I designed, but never built, a tiny one for throwing a 3/8" section of 1/4 inch aluminum dowel, using braided "solder wick" for contacts instead of rails.  But my son borrowed my big caps and I haven't seen them since. I also intended to use the big neo magnets from a voice-coil driven hard drive for the mag field.

If I had got the thing to even eject the aluminum rod, I would have considered it a great triumph.

I was pretty sure I got the right-hand-left-hand motor and generator rules mixed up, as well as "north-seeking" versus "true north" poles of the magnet mixed up, but I figured there were only four combinations to try in order to get it right.

Might have shot backwards on one combination, though. 

Still, a micro-triumph.  Yay, Terry!

Terry, 230RN

[roo_ster]

I love to see the effect of such a projectile that had a clustering/self-fragmenting charge go off some set number of meters before it hit the target.  Yeah, less penetration for heavily armored targets, but most naval gunfire targets are not of that sort.

MV for comparison:
Rail gun `~3000+m/s
LOSAT     ~1800m/s
TOW       ~260m/s
5.56NATO ~940m/s

[230RN]

^ Thanks.  I was going to look those up.

By the way, I dug out my original sketch of mine --more of a schematic than a "design."  The projectile itself was its own "rails" in this case, and current would be cut off as the slug passed the braided conductors (see inset at upper right):



It was supposed to be enclosed in a tube for guidance and to prevent tipping (flipping over) of the Al slug.

Like I say, I probably got the RH and LH motor and generator rules mixed up, as well as "north-seeking" versus "true north" poles of the magets.  And I'd have been happy just to see it eject the slug in one combination.

Terry, 230RN

[roo_ster]

The answer for fleet electricity generation: nukes, nukes, and more nukes.

http://en.wikipedia.org/wiki/California_class_cruiser
http://en.wikipedia.org/wiki/Virginia_class_cruiser

"You can never have enough nukes."
----John Derbyshire

He has shown us the way...
http://en.wikipedia.org/wiki/Hyman_G._Rickover

[kgbsquirrel]

I was trying to figure that out too.

The projectile/armature looks like it's just a test payload and not too aerodynamic Hard to say, but it looks like it might be yawing a bit. I think in a deployable system, the armature that bridges the rails would be a two piece sabot that falls away, with a dart similar to an APDS in the center.

This one shows what is more likely to be close to some of the final production kinetic projectiles: http://youtu.be/1ix62_oBGtg