Navy Railgun Tests Leading to Ship Superweapon by 2020

Thunderfoot · Mar 1, 2012

Umbran said:
The need to steer is largely dependent on relative speed and distance to target. If the target's pretty much sitting still, a straight-line path is fine, as the target can't get out of the way before the projectile gets there. And these projectiles are intended to go twice as fast as an SR-71.

That being said, the article makes it seem that these are intended to take the place of standard cannon and ship to ship guns and ship to shore missiles.

I agree the ship to ship application looks great, and if ship to shore attacks were still conducted like they were in WWII, this thing would be great for that, the collateral damage caused by dumb weapons means this thing is dead on arrival except on maybe a few cruisers. (remember, we only have two battleships in reserve as floating museums and 2 have been mothballed (floating in a harbor with no personnel, munitions or fuel on board.)

These would be great to replace the main guns on a battleship, but the question is why? We don't use them anymore. When you have every human rights organization complaining when a civilian target is hit in a smart weapon application. I just can't see the Military approving a weapon that is akin to giant catapult (even an effective one) being mounted as a viable ship to shore system.

Umbran said:
In terms of energy, the 33Mj railgun would be like a 33 ton car, moving at 100 mph.
<SNIP>
How that energy is delivered matters. A lot.

Which is why that ship to ship application makes much more sense.

Thunderfoot · Mar 1, 2012

While the Navy is researching this, the Army and Marines would have a much better use for this thing; Drag along artillery. A dumb weapon firing projectiles at around Mach 8 with 33Mj of impact. An artillery barrage of one battery firing once could devastate a brigade sized force in seconds, even under "hard" cover.

And while it being a powered system does have it's drawbacks when compared to a conventional weapon, the margin of error on the battlefield for self-inflicted accidents (cooking a round in the chamber, igniting your ammunition, etc.) seems to drop considerably. Friendly fire accidents, though, would be simply horrific.

Thunderfoot · Mar 1, 2012

Janx said:
so we knwo the bullet is like 33 tons hitting at 100mph.

But if the bullet is so small, how is it going to damage a large area and not just punch a fist sized hole in the side of the target?

So far, all we have seen is a shell approximately the size of 100-pounder.
The hole would be significantly larger than fist sized, closer to Shaq sized or, if they can rig it to tumble on impact, Dumbo sized.

Umbran · Mar 1, 2012

Janx said:
But if the bullet is so small, how is it going to damage a large area and not just punch a fist sized hole in the side of the target?

Do you want to damage a large area on the surface of a target, or do you want to damage critical systems or supports *inside* the target?

Punching through the side of the target is just fine. Having penetrated, your metal slug is now fracturing, rolling, tumbling and ricocheting around inside a big metal or concrete box. Mayhem ensues.

Also, remember, the projectile itself is just a metal slug. Compared to a missile or rocket, it is probably cheaper than dirt, small as a speck, light as a feather, and free of explosive risk. You can carry a bazillion of them, and shoot them all day long, so long as you have power in your vessel.

Umbran · Mar 1, 2012

Thunderfoot said:
The railgun is a large hand fed cannon that uses a high-energy propulsion system (ie an engine (which would need to be separate from the ship's engine.))

Two things:

1) The *test* version is hand fed. Don't expect it to stay that way in a fully weaponized production version. Automating the loading of solid slugs is child's play by comparison to getting the launch system to work.

2) The energy source does not need to be separate from the ship's engine. If the ship's engine can be used to just generate electricity, rather than motive power, then the ship's engine does just fine.

Yes, there is a collateral-damage argument for ship-to-shore applications, in general. But don't think "bombardment", but instead tactical strike at range.

Typical ship-to-shore these days is usually done with explosive rounds or missiles, right? Rounds are fired in ballistic arcs, and from a moving ship accuracy is an issue. And missiles are steerable, but depend on explosive power, and so do a lot of collateral damage.

This thing's round is flying faster than either of the other munitions. Motion of the launching platform is thus less of an issue, and lack of explosive power means that you'll damage what you hit, and less of anything else.

So, there's a tank or gun emplacement on the shore? Not for long!

Umbran · Mar 1, 2012

Thunderfoot said:
And while it being a powered system does have it's drawbacks when compared to a conventional weapon

I think you underestimate the power requirements here.

A single one of these rounds carries enough energy to melt 70 pounds of room-temperature iron. Let me crunch some numbers...

Okay, an M1 Abrams tank has a 1500 horsepower engine. If I have my math right, if you put the entire output of that engine into one of these guns, you could fire one round every 30 seconds or so.

Thunderfoot · Mar 1, 2012

Umbran said:
Two things:

1) The *test* version is hand fed. Don't expect it to stay that way in a fully weaponized production version.

2) The energy source does not need to be separate from the ship's engine. If the ship's engine can be used to just generate electricity, rather than motive power, then the ship's engine does just fine.

Yes, there is a collateral-damage argument for ship-to-shore applications, in general. But don't think "bombardment", but instead tactical strike at range.

This thing's round is flying faster than either of the other munitions. Motion of the launching platform is thus less of an issue, and lack of explosive power means that you'll damage what you hit, and less of anything else.

So, there's a tank or gun emplacement on the shore? Not for long!

But see that's the issue the Navy doesn't shoot tanks or gun emplacements anymore, that tactic went out in the Korean war. They are either hit from airborne weapons (tactical bomb runs) or land based artillery. And the collateral damage from an exploding munition has been offset by the steerage issue. Ships no longer use ballistic arcs in weapons delivery,it isn't needed. Which is why I said as a ship weapon this thing is okay, but would be better suited for land based artillery, where all of the things you described are still a real world consideration.

As for tactical strike at range versus bombardment, I call BS - there is no such thing with dumb weapons, that's why ships don't bombard anymore, you can't control the variables: wind, weather, magnetic pull of the earth, low flying hippopotamus, whatever. When you have a steering system you can ignore the variables and destroy your targets at will.

Typical ship-to-shore these days is usually done with explosive rounds or missiles, right? Rounds are fired in ballistic arcs, and from a moving ship accuracy is an issue. And missiles are steerable, but depend on explosive power, and so do a lot of collateral damage.

Wrong. There is no explosive round shore bombardment - THAT is my point. Also, ships stop moving when bombarding a shore anyway. It was never an issue about accuracy in a bombardment role. One of my favorite weapons demonstrations was the USS Iowa demonstrating the power of it's naval guns, it opened up a barrage on the top of a mountain on a target island and left a "flat" area where the mountaintop was. Your concept of what a naval bombardment is capable of is woefully underestimated, something that surprises me greatly.

Like the issue about wholesale slaughter to achieve tactical means in another thread, where you rightfully stated that you cannot kill indiscriminately for tactical means. That's why shore bombardment went from guns to missiles, it doesn't eliminate it, but it reduces it to an acceptable level.

Thunderfoot · Mar 1, 2012

Umbran said:
I think you underestimate the power requirements here.

A single one of these rounds carries enough energy to melt 70 pounds of room-temperature iron. Let me crunch some numbers...

Okay, an M1 Abrams tank has a 1500 horsepower engine. If I have my math right, if you put the entire output of that engine into one of these guns, you could fire one round every 30 seconds or so.

Again, artillery - an M1A3 Abrams is a tank, not the same thing. You set up a portable power station that power four guns in a "drag mobile" battery and have your way with the enemy. You are effectively reversing your position on the ships engine argument from a few posts ago.

Umbran · Mar 1, 2012

Thunderfoot said:
But see that's the issue the Navy doesn't shoot tanks or gun emplacements anymore, that tactic went out in the Korean war.

Yes. My point is that new weapons, with new performance characteristics, may change that.

As for tactical strike at range versus bombardment, I call BS - there is no such thing with dumb weapons

There is no such thing with *current* dumb weapons. My point is that this round will behave differently than the cannon shells you're thinking about, and so may be useful for other tasks.

Let's do a bit of comparison:

The 16" main guns on an Iowa-class battleship fire a round that weighs well over a ton, with a muzzle velocity of 820 m/s. And...

"The large caliber guns were designed to fire two different 16-inch (410 mm) shells: an armor piercing round for anti-ship and anti-structure work, and a high explosive round designed for use against unarmored targets and shore bombardment."

(So much for not using explosive rounds!)

The rail gun should fire a round that weighs a mere 40 pounds, at three times the muzzle velocity of the Iowa guns.

that's why ships don't bombard anymore, you can't control the variables: wind, weather, magnetic pull of the earth, low flying hippopotamus, whatever. When you have a steering system you can ignore the variables and destroy your targets at will.

Yes, but having to carry a precision steering system makes the round far, far more expensive.

The railgun round is *tiny* by comparison, and for the same range, spends a third of the time in flight. This should drastically reduce inaccuracy due to environmental factors, or motion. It may be able to do the work of a guided round, without the expense of guidance!

Also, ships stop moving when bombarding a shore anyway. It was never an issue about accuracy in a bombardment role.

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.

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?

Your concept of what a naval bombardment is capable of is woefully underestimated, something that surprises me greatly.

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!

Thunderfoot said:
Again, artillery - an M1A3 Abrams is a tank, not the same thing. You set up a portable power station that power four guns in a "drag mobile" battery and have your way with the enemy. You are effectively reversing your position on the ships engine argument from a few posts ago.

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!

Dannyalcatraz · Mar 1, 2012

Janx said:
so we knwo the bullet is like 33 tons hitting at 100mph.

But if the bullet is so small, how is it going to damage a large area and not just punch a fist sized hole in the side of the target?

Thunderfoot said:
So far, all we have seen is a shell approximately the size of 100-pounder.
The hole would be significantly larger than fist sized, closer to Shaq sized or, if they can rig it to tumble on impact, Dumbo sized.

Umbran said:
Do you want to damage a large area on the surface of a target, or do you want to damage critical systems or supports *inside* the target?

Punching through the side of the target is just fine. Having penetrated, your metal slug is now fracturing, rolling, tumbling and ricocheting around inside a big metal or concrete box. Mayhem ensues.

Also, remember, the projectile itself is just a metal slug. Compared to a missile or rocket, it is probably cheaper than dirt, small as a speck, light as a feather, and free of explosive risk. You can carry a bazillion of them, and shoot them all day long, so long as you have power in your vessel.

If it helps, think of this as an AP round. A very nasty AP round.

If a small enough version could be made- as in smaller caliber & thus power requirements and recoil- this could be a great weapon for tankbusting aircraft.

In addition to the effects Umbran mentioned, even if the round doesn't actually penetrate, it could kill via spalling. We also know that plasma is generated at launch, so the round itself is likely to be quite hot...hotter than conventional rounds. It may be able to deliver some of that heat energy as well as its kinetic energy, making it a de facto incendiary round as well.

And remember, this is still early-stage stuff. It is possible that, just as in gunpowder weaponry, they may be able to develop special rounds for these weapons. A railgun version of grapeshot could be hideous, for instance.

Not only would that be nasty for antipersonnel purposes, but if used in AA emplacements, accuracy becomes a non-issue- point at an area of the sky and hit everything in it with Mach 10 slugs, and most of that stuff will fall down.