Navy Railgun Tests Leading to Ship Superweapon by 2020

Mustrum_Ridcully · Mar 6, 2012

Umbran said:
Well, let's note that you started with "form of energy". Gas and plasma (which is just ionized gas) are not "forms of energy" any more than your body, or any physical matter, is a "form of energy".

But no, you can't accelerate a gas or plasma with a rail system like you can a solid projectile. If you jump a current through a gas or plasma, you get a lightning bolt,

Lightning Gun!

There are ways to accelerate charged particles. Every CRT TV and monitor does this. So do the ion drives for spacecraft currently under development. They just do it differently than rail systems do.

I thought the first probe with a ion drive is already in space? (Of course, more will be in development...)

Edit:
An Example craft with ion drive was the SMART-1: http://en.wikipedia.org/wiki/SMART-1

Umbran · Mar 6, 2012

TanisFrey said:
The projectile does not need to have its own magnetic field, alto it helps. All you need is ferrous metal, that is metal that reacts to a magnetic field.

The projectile being a magnet actually isn't a particular help, and the projectile does not need to be ferrous. It merely needs to be conductive. As the current flows, the rails and projectile become one big electromagnet. The field of that electromagnet then interacts with the current running through the projectile producing a force on the projectile.

It produces a force on the rails too, pushing them outwards, but you bolt them down so they don't move - the only thing that can give way is the projectile, so it takes off.

Nagol said:
Recoil is only dependent on the momentum gain of the projectile and other particles -- like escaping gases. How that projectile gets its momentum boost is immaterial.

Correct. We are talking some of the most basic an inviolable physics, right up there with "a body in motion tends to stay in motion". *SOMETHING* feels an opposite force. If you can monkey around so that opposite force gets transferred so that it doesn't move your gun around in ways you don't like, that's good. But, for a railgun, you have to do special work to do it - it does *not* automatically minimize it.

Mustrum_Ridcully said:
Lightning Gun!

Well, the current would flow through the easiest path from one rail to the other rail. Unless your target happens to be between the rails, you ain't shootin' it with lightning from a railgun.

I thought the first probe with a ion drive is already in space? (Of course, more will be in development...)

To my knowledge, there have been six missions from various agencies equipped with one variation of an ion drive or another. But, for all of these missions, testing the drive was one of the major goals of the mission, so I consider them part of the development effort.

jonesy · Mar 6, 2012

Mustrum_Ridcully said:
Lightning Gun!

[ame=http://www.youtube.com/watch?v=R617vPlqinI]Tesla gun - YouTube[/ame]

Mustrum_Ridcully · Mar 6, 2012

Umbran said:
Well, the current would flow through the easiest path from one rail to the other rail. Unless your target happens to be between the rails, you ain't shootin' it with lightning from a railgun.

Enemy of Fun you are. I knew it wouldn't really be practical.

To my knowledge, there have been six missions from various agencies equipped with one variation of an ion drive or another. But, for all of these missions, testing the drive was one of the major goals of the mission, so I consider them part of the development effort.

According to the (german) Wikipedia article, there are apparantly even new communication satellites in use with it. That surprised me a little. But then I just today realized that the game Startrek 25th Anniversary was made in the 90s.

Mustrum "Time Flies" Ridcully

Thunderfoot · Mar 7, 2012

Umbran said:
Yes. My point is that new weapons, with new performance characteristics, may change that.<SNIP - for space saving sake>
Well, in explosive bombardment, accuracy isn't really that big a deal. You carpet an area with 1-ton explosive bombs, everything's going down.

Okay, let's just agree to disagree on this until sea trials.

Umbran said:
However, despite your claim, no ship on the sea is ever really "stopped", especially when they're tossing out major ordinance. When you're considering hitting a target miles away, small motions matter. And Iowas certainly do rock when they open up with those guns, do they not?

lolz - yeah I was thinking the same thing. But when you talked about movement, I assumed you meant shoot on the run, something tanks can do, and ships sort of do when fighting other ships. They come to "stop" when bombarding. And yeah, the Germans found out about naval bombardment and ship roll the hard way. :lol:

Umbran said:
My point is that this gun isn't useful for that classic "bombardment" - which, as noted above, did use explosive rounds (there's "bomb" in "bombardment", you know ). It is a different weapon, with different capabilities. Stop thinking of it like a standard cannon, because it isn't one!

Now here is where we agree. My point was one of the stated uses was classical bombardment, which I stated was foolish. Now I still think as a ship to ship this thing is awesome in a bottle of hot sauce.

Umbran said:
My point is that this weapon has power requirements equivalent to a tank. Somehow, you're going to have to carry along tank-scale engines. So, why drag the gun behind, and have the risk of a separate power source?
Mount it on an un- or lightly-armored chassis with an Abrams engine. When it isn't firing, the engine drives electric motors to move the thing. When you need artillery, drop the stabilizing legs, shift that engine to charging capacitors, and fire away

Ah, got it. Actually you would mount this on a M155A3 Paladin Chassis (Self-propelled Artillery), beefier recoil suppression, larger ammo containment, better engine (for this purpose - more power less speed), less computer storage and less "super cool" tank driving mechanisms.

But, even with self-propelled, the Military still uses drag along as well, and since you have to set up a command station when you employ a battery, a separate power station would be easy to add the mix. And if they did employ it using both platforms, you now have standardization across the board for artillery. Something that makes the Pentagon really really happy (as well as congress because they no longer have to pay large sums for multiple weapons systems.) So while I don't disagree with your mobile artillery usage (and in fact heartily agree that would be the most efficient usage) drag along could be revolutionized by this technology.

Olgar Shiverstone · Mar 7, 2012

Thunderfoot said:
Ah, got it. Actually you would mount this on a M155A3 Paladin Chassis (Self-propelled Artillery), beefier recoil suppression, larger ammo containment, better engine (for this purpose - more power less speed), less computer storage and less "super cool" tank driving mechanisms.

But, even with self-propelled, the Military still uses drag along as well, and since you have to set up a command station when you employ a battery, a separate power station would be easy to add the mix. And if they did employ it using both platforms, you now have standardization across the board for artillery. Something that makes the Pentagon really really happy (as well as congress because they no longer have to pay large sums for multiple weapons systems.) So while I don't disagree with your mobile artillery usage (and in fact heartily agree that would be the most efficient usage) drag along could be revolutionized by this technology.

The Paladin's an M109A6

. And the Paladin Integrated Management system (PIM), the upgrade, is based on a high-voltage 600V system. But it in no way produces enough energy to power a rail gun. Nothing that can fit on or be towed behind a military vehicle does -- at current technology, you need 2-3 semi-trailers worth of power generation for multiple shots. Heck, even the supercapacitors UT Austin used in their ground-vehicle railgun were too big to fit on a ground vehicle, so right now you can't even carry the power for a since shot on a modern SPH.

The power tech needs to go a few generations before ground use is practical, which is why Naval use is a great place to start.

Thunderfoot · Mar 7, 2012

Olgar Shiverstone said:
The Paladin's an M109A6 . And the Paladin Integrated Management system (PIM), the upgrade, is based on a high-voltage 600V system. But it in no way produces enough energy to power a rail gun. Nothing that can fit on or be towed behind a military vehicle does -- at current technology, you need 2-3 semi-trailers worth of power generation for multiple shots. Heck, even the supercapacitors UT Austin used in their ground-vehicle railgun were too big to fit on a ground vehicle, so right now you can't even carry the power for a since shot on a modern SPH.

The power tech needs to go a few generations before ground use is practical, which is why Naval use is a great place to start.

I knew that - crap - it's been too long since those guys woke me up while I was trying to get sleep after a mid watch.

As for the power - how long it would take to ramp back up using a conventional power plant, assuming a smaller shell than the Navy test? And if the drain is that much what wouldn't that be a problem on the small diesel electric engines of naval gunships? Only the cruisers would have the kind of power it would take to run those and the rest of their ships systems. (My cousin was a scope dope on a destroyer - he said when they did evasive actions they had to pull power from other systems, usually lighting and environmental systems (ie, lower priority).
Considering the 5" is the standard ship mounted weapon the rail would actually reverse the downsizing of the main gun, and even if it is a guided package, most vessels would only have one or two of these on board. Power would still be a problem for these little ships if it takes the power plant you're describing. That would mean that no current application is possible. Wonder if the testing is trying to downsize the power plant?

Dannyalcatraz · Mar 7, 2012

Downsizing HAS to be at least part of the process.

TanisFrey · Mar 7, 2012

Umbran said:
The projectile being a magnet actually isn't a particular help, and the projectile does not need to be ferrous. It merely needs to be conductive. As the current flows, the rails and projectile become one big electromagnet. The field of that electromagnet then interacts with the current running through the projectile producing a force on the projectile.

It produces a force on the rails too, pushing them outwards, but you bolt them down so they don't move - the only thing that can give way is the projectile, so it takes off.

Correct. We are talking some of the most basic an inviolable physics, right up there with "a body in motion tends to stay in motion". *SOMETHING* feels an opposite force. If you can monkey around so that opposite force gets transferred so that it doesn't move your gun around in ways you don't like, that's good. But, for a railgun, you have to do special work to do it - it does *not* automatically minimize it.

My bad, I did not mean ferrous (indicates the presents of iron) but relatively reactive to magnetism. Most materials that are conductive will be reactive to magnetism.

When I speak of minimizing recoil I do not mean that it is eliminated but reduced to the minimum expected by the monument being generated in the projectile.

A standard gun has more recoil than what can be expect to be generated by the monument of the bullet. Due to the following:
1) The need to over come friction of the bullet with the barrel.
2) The expanding gasses that propel the bullet. (Automatics and semi-automatics use this to reload the weapon.)
3) The Explosive force is in all directions including direction not directly in line with the path of the projectile. These do get redirected into the expanding gasses.

These 3 items are eliminated be the rail gun, leaving only Newton's Laws of Motion.

Kzach · Mar 7, 2012

Mustrum_Ridcully said:
Lightning Gun!

Now you're talking!

Umbran said:
Well, the current would flow through the easiest path from one rail to the other rail. Unless your target happens to be between the rails, you ain't shootin' it with lightning from a railgun.

Sigh, such a buzz-kill