Credo
"Sign on, young man, and sail with me. The stature of our homeland is no more than the measure of ourselves. Our job is to keep her free. Our will is to keep the torch of freedom burning for all. To this solemn purpose we call on the young, the brave, the strong, and the free. Heed my call, Come to the sea. Come Sail with me." -- John Paul Jones
"Pardon him, Theodotus; he is a barbarian, and thinks that the customs of his tribe and island are the laws of nature" --George Bernard Shaw, "Caesar and Cleopatra"
"And those who were seen dancing were thought to be insane by those who could not hear the music."--Friedrich Nietzsche
"A kind Providence has placed in our breasts a hatred of the unjust and cruel, in order that we may preserve ourselves from cruelty and injustice. They who bear cruelty, are accomplices in it. The pretended gentleness which excludes that charitable rancour, produces an indifference which is half an approbation. They never will love where they ought to love, who do not hate where they ought to hate."--Edmund Burke
“You say that it is your custom to burn widows. Very well. We also have a custom: when men burn a woman alive, we tie a rope around their necks and we hang them. Build your funeral pyre; beside it, my carpenters will build a gallows. You may follow your custom. And then we will follow ours.”--General Sir Charles Napier
"Μολὼν λαβέ" -- Leonidas
"Blogito Ergo Sum" -- Neptunus Lex
That v part is squared in kinetic energy = ½mv².
OK for shore bombardment I suppose. Fixed target, no target motion. Against ships? How we doing the whole battle damage assessment at those kind of ranges in real time?
Reminds me of EXWAR conference in Panama City years ago when the Deputy CG for Army Doctrine talked around 3 stories as he wove his narrative. One of the stories was the giant Big Bertha and how it could fire precisely calibrated gigantic shells 24 miles into downtown Paris. Each shell of just enough different size to take into account barrel wear from the preceding shots and make sure the lands and grooves were firm at the borrelet.
So the Germans fired it at Paris and Prince Rudolph said, “oh how nice! What did you hit?” and the senior staff hemmed and hawed a bit and said, “uuuuummmm, Paris.” A young staffer said that if the Prince would give him a couple of hours he would let him know and then sent a bicycle messenger down to the closest town to Paris they controlled to buy the newspaper.
I’d think that BDA could be done the same way as it is currently done for targets beyond visual range. If you’ve got eyes on the target, the distance you have to send the targeting data would seem to be irrelevant.
I recall decades ago reading the memoirs of one of the key scientists working on small atomic warheads. At that time, they had developed warheads that would “fit within a briefcase’.
And that was more than 30 years ago.
I remember in GW I, while many cried to silence Fred Francis, it seemed lots of warfighters were carefully watching CNN…well, kinda like riding into Paris on a bike, only letting the rabid left wing “journalists” go in harms way to conduct your BDA….ah, the advantages of an American hating MSM…..you know they’ll be running to get the local opinions, and the “enemey” will welcome them, to employ that form of propaganda….a twofer.
well, we already know what a long rod penetrator does at the velocity a 120mm smooth bore can get it up to…
now imagine what a chunk of DU is going to do at railgun velocity. if anything, you’ll have to adjust the design so it *does* deform, otherwise you might just go right through with minimal damage, except for spalling…
We should have lots and lots of DU, since we are going to decomm all but 300 warheads….
“We should have lots and lots of DU, since we are going to decomm all but 300 warheads….”
You don’t get DU from decommed warheads.
Natural Uranium has several isotopes contained within it.
What the Military and others use for nuclear weapons and for nuclear fuel in reactors is U-235. A highly radioactive and fissionable isotope.
This isotope is in a tiny fraction of a percent of natural Uranium.
The vast majority of natural uranium is the isotope U-238. It has an extremely low radioactivity (compared to U-235), is NOT fissionable, and is useless for reactor fuel or the physics package of nuclear weapons.
To get the desirable U-235 out of natural uranium, it has to go through an “enrichment” process that extracts the U-235 out of the ore. What is left behind is mostly useless U-238 and is even less radioactive than normal natural uranium (because the U-235 has been removed or “depleted”).
This leftover slag material, the useless U-238 is what is used and called Depleted Uranium.
The dangers of handling DU rounds is not from radioactivity, DU is about 60% less radioactive than natural uranium, which in itself is only mildly radioactive in its natural state. Highly radioactive uranium is the refined and concentrated U-235 that has to be concentrated because it is (as I said above) only a tiny fraction of a percent of natural uranium.
The danger of Handling DU rounds has more to do with it’s toxic properties as a “Heavy Metal”. Think “Lead poisoning”.
And after more than 50 years of refining Uranium for nuclear weapons and fuel production, the US has more than 500,000 TONS of DU just sitting around in storage, so we gots plenty!
CG: Thanks for the lesson. Right after I typed the above, I thought “maybe that’s not the source.” but, too late, so you fixed up my knowledge base.
So what will we do with all the weaponized stuff from the dismantling? Sell it to Iran before Mid-Jan 2013?
Mix it with depleted uranium down to 2-5% enrichment and lease it out as reactor fuel.
Any day you are not learning something new, is a day you are not living.
Loved the write-up you did on The Battle Off Samar. Hornfischer’s book “Last Stand…” is one of my favorites along with Dick O’Kane’s “Clear the Bridge”.
I’ve lobbied long and hard trying to get Hollywood, most specifically Spielberg and Hanks (Band of Brothers/The Pacific) to try to use Hornfischer’s book as the basis for a screenplay.
A couple of errors there. First off, it’s a bit of a stretch to characterize U-235 as highly radioactive. It’s more radioactive than U-238 (not much isn’t), but with a half life of 700 million years you’re not exactly going to be able to find it in the dark.
Secondly, U-238 is fissionable, just not with thermal neutrons. Fast neutrons will fission U-238, though only in specific energies. A fact that has been used by fusion weapon designers. By encasing the pit in a depleted uranium tamper the fast neutrons from the initial explosion could be captured to cause more fissions and release more energy.
for the lethal mechanism they should include some options, a boxing glove on a spring, a array of forks, or maybe just Hillary clinton painted on the nosecone
Geez joe, if they use the latest images of Hillary they’ll end up having the weapon banned like lethal gas. Far too inhumane.
scissors!
Love that slogan on the command insignia “Velocitas Eradico”. Quick internet search indicated it translates to “Speed Kills”.
George V.
Not only arttillery but possibly a cheap launch-to-Orbit
mechanisum?
Hienlein looks down and smiles…
Hienlein looks down and smiles…
Indeed.
The Moon is a harsh mistress.
Heinlein was an engineer…and his idea was to launch materials (in his case, wheat grain) from 1/6 G down the gravity well with a splash down into water. Shooting UP the gravity well means that to get to the moon you’d need a hell of a lot more delta vee than the other way around.
Something I noticed about the test: the test round looked like a dumb bell with a flat face. I thought that was kinda stupid at first then realized that the shape was exactly right for a test: you really didn’t want a nice areodynamic shape like the fin stabilized sabot round. I expect that if they had used s sabot round shape that it would have gone through the targets and ended up in places they didn’t want it to go, like someones house. It wouldn’t be hard to compute the difference between the shape they used and a war shot shape for values of real penetration and distance.
Curtis, at the velocities this weapon will be traveling at, target movement won’t mean much. Computers will take care of leading the target. And all that mass hitting the target will transfer a huge energy load in an instant…BIG explosion. Use a DU round or similar, and you have chunks of very hot metal flying around starting nasty fires (think magnesium).
Byron,
I have no doubt you’re right it’s just that my experience with TWS was out to not more than 20 nm. Anything involving OTH in real time required a seeker head on the weapon and flight controls. I am probably one of the very few here that never operated at sea other than as an independent steamer and never with a BG. I did one bit or two as FCO on a Spruance doing ASWOPS 85-6 and another one working with a lot of P3s out of Alaska or someplace but OTH, outside firing Harpoon on ELINT hits down the bearing was kind of hit or miss.
I have to admit I did work at one TFCC. An important one but even there OTH sucked because most of the GCCS-M tracks were like 20 hour time late track data which means they were worthless. Wherever the FOTC was he was not doing his job. The TFCC SWO stopped calling me in for my biweekly duty call as deputy because I made the crew work like slaves and crack the whip on the FOTC and suggest that near real time meant near real time. And they didn’t like me either when I showed up inside PMW 157.
Curtis – as a TFCC WO, I always told the watch that JOTS/GCCS-M was just a forecast based on old data – and as such, was almost certainly lying.
I was helping figure out just how to use TASM at max range in a BBBG in Aug 86. The flood of “overhead” and other ELINT was crushing. Had a great OSCS(SW), who worked diligently to sort the correlating hits, but it was daunting. Actually, we retained all the traffic, graphed it for time of detect v time of receipt (on the headers) and opened the eyes of the 1620s who thought they were hot stuff. We learned way too much about the issues in using those sensors and trying to translate it to the tactical engagement realm quickly. That exercise is also what prompted CAPT Gauss to provide POST to the Thawk units. That also, several months later prompted CAPT Gauss to stare at ADM Borda and tell if if the Crypies stole one more POST system to put behind the Green Door, he was personally going to take them all back…ADM B, turned to his 1620 and directed proper installations be done….Oh, those were the days….
Byron, thanks. I was wondering about the goofy shape of that test round, but what you say makes sense.
They’d have to crank the acceleration way down for human launches on this sucker.
Against moving targets? If the brain trust can get this going, they can replace some F-18′s and AV-8′s (no really!). Hell, these could replace some Patriot missiles as well. And we can finally retire the battleships and put the fear of God into China’s navy.
Of course against moving targets. You just have to lead them.
Hyper-velocities?
Even better. You just don’t lead as much!
And the battleships are retired, by about a decade now. Missouri was the last and she’s a museum ship right next to USS Arizona at Pearl.
Two of the Iowa class have to be kept ready. The Marines and some in congress miss those big guns.
Yeah, nothing like teh crazy of a TASM doing 454 kts for 30 minutes to get to a target 250 NM away…doing maybe 16 kts perpendicular to the direction of the ASM’s approach…those were the days….
Rods from… Offshore.
No more “gunning” the other guy…now we’ll have to change our terminology: “Should I rod him, Captain?”
Might go over well in this post DADT era, just you’re have to be sure you’re using it in the right context, or there could be “dumbells out” when you were asking an entirely different question…
Much of the early NRL funded research in this was done at a small engineering school in my neighborhood. Interesting read in this slide deck about some of the issues and applications:
http://www.dtic.mil/ndia/2007armaments/Fair.pdf
To Scott: Thanks for that very informative link. A tad bullish, that .ppt, at least as academic-sourced chartware goes. But nicely comprehensive.
I ran into a GA guy at a Fleet Week demo last year, standing beside his mock-up rail gun, equipped with pictures of various naval applications. Quite bullish he was, as well, on getting that technology working and deployed in our near lifetimes. They were showing a “small one”, built on their own stockholders’ nickel IIRC, that might go on the smaller ships. (Can one dream of a real gun on the LCS? No, ‘twould be too good to be true).
Having discussed the use of Sabot-style rounds for penetration, Mr. GA guy, when asked about how such a weapon might handle non-point dispersed targets such as vehicles or troops, averred there was the possibility of rounds with heads that would fracture or fragment, with the statement that “even small splots of hypervelocity titanium could release a LOT of energy in a most effective fashion”. The presentation above starts to explain that a tad, with the bit about mini-rods.
But neither Mr. GA, nor the presentation linked above, talks much about guidance and in-flight correction, a critical capability that is glossed over or assumed away. Finding the electronics that could withstand that launch acceleration and mag field might be trickier than has been thought of so far. And I am not sure we have a great deal of of ready experience with guidance at hyper-velocities.
And look at the flight profile chart for the really long range proposal (200nm+); that puppy would be arching up out of the atmosphere and into low earth orbit. Heck, not only would one need to deconflict your flying aircraft, you would also have to check carefully for flying space junk, of which there is evermore a lot in the realms of LEO.
On the land application side, I have been seeing a lot of work by some around the auto industry on miniature hyper-velocity (in vacuo) flywheels, such that might be positioned one to a wheel, to be spun up by braking and provide boost power on acceleration, all at minimal cost in weight and space. There are some that hold that these (yet to be offered commercially) mini-flywheels might be a viable replacement for bulky, massive batteries in hybrid applications, and serve as a way to put a goodly further kick on auto fleet MPG for lower cost and complexity than batteries, while not further depleting the world supply of lithium.
So now imagine banks of these mini-flywheels used to build up power to drive the rail gun. Might be just enough to get one into a tank, or a self-propelled howitzer.
So I wish the lads and lasses working on this project all the best success – this rail gun thing could be a huge difference maker for our under-gunned Navy. And as Dad to a Marine, I’d like to see us get back into the business of naval bombardment. And also hope that somewhere over in Guangzhou there are not so bright lads figurin’ out how to do it for themselves, without the courtesy of checking for patents and all that other inconvenient intellectual property stuff.
CT, your comment regarding flywheels is something close to my heart. Well, close to my office, actually, but also something I’ve a bit of experience with. What they’re doing, to use the physics term, is taking kinetic energy and turning it into potential energy, the spinning mass of the flywheel. Potential energy can be tapped at any time and provides a ready source of instant power when your normal power source can’t handle such a load.
In my office is a box containing a flywheel of roughly 2 tons spinning in magnetic bearings. The job of this flywheel is to regulate our electrical power, so if mains power drops below 115vac a generator taps that flywheel and spins it down a bit to boost the power. When power hits 117vac the rig starts spinning that flywheel back up to 55Krpm, its normal speed.
I am convinced a bearing will fail and the darned thing will break free and roll through my office.
In a car, a similar arrangement allows us to use magnetism to take kinetic energy away from the wheels and store it as potential energy in the batteries. The term is regenerative braking. That same device allows us to draw a lot of battery power and turn it into acceleration, knowing we’ll take a lot more time to put that energy back into the batteries once we’re done squealing the tires.
Likewise, in a railgun we need to provide a whole lot of power at one time rather than the lots of power over a long time that things like boilers, nukes, and generators generally provide. In other words, we need a source of potential energy to draw from and convert into short-term kinetic energy. Typically capacitors are used for this purpose but there are other methods.
On the topic of in-flight guidance, it may not be strictly necessary if one can accurately measure the position and movement of the target. Let’s think about this…
Let’s say I’m shooting a pheasant with my shotgun. The distance is typically about 50 feet, and shot leaves the shotgun at just over 1000 feet-per-second (but slows rapidly). At that distance I may have to lead a bird a bit but 50 feet divided by 1000fps is 0.05 seconds, so at most I have to aim a few milliseconds ahead of him. A few milliseconds of advantage does the pheasant no good, he cannot possibly change speed or direction in so short a time. If I aim right, I’ll hit him and there’s nothing he can do about it.
Now let’s look at the same thing with a railgun. A ship 25 miles away can be hit by a projectile at 5000mph in 18 seconds. That’s a lot more time to move than a pheasant has, but ships don’t turn on a dime and it takes minutes for them to even start to change speed or direction. Plus they’re a lot larger than a pheasant. If the plot is accurate those 18 seconds to impact are inevitable, like death and taxes.
Look at the railgun for a shore bombardment. At 100 miles it may not be as accurate, but the shell will only take a minute to get there. One minute to hit a city and last I’d heard cities don’t move much. A shell coming in at that speed will penetrate anything — E=MV^2 and with such a velocity there’s a whole lotta E to dissipate when the shell hits. That E gets turned from potential energy of a shell in flight to kinetic energy, which is to say things flying about and explosions and all the goodies you want when shooting somebody.
If the target course and speed are known, this railgun is gonna do a Billy Jack on them. It’s going to take this foot, put it on that side of your face, and there’s nothing you can do about it.
– Max
Max,
I may have missed the gun on this one. The rail gun launches that shot with a muzzle velocity somewhat greater than 5000mph and it shoots one after another. How does that ‘opposite but equal reaction’ work in this context? Does the mount fail or do the stress fractures in the hull count as a mission kill on ownself? We couldn’t deploy the 8 inch single gun mount because the superstructure couldn’t withstand the forces involved.
I’m not sure how you shoot a railgun at targets just over the horizon. Wouldn’t gun be pointed almost straight up? Wouldn’t the projectile just follow a ballistic path from the moment it left the muzzle, rise to the point where it shed all the launch energy and then fall back to earth at terminal velocity which I don’t believe is anything like 5000mph? At 25 miles I think I can guarantee that if you shoot something moving at 5000 miles per hour/you’ve aimed high with no way to correct. It’s like trying to put a laser on the target which one might do if your laser is atop your mast but railguns won’t be found in the mast tops.
Seriously if you had a whole swarm of suicide boats coming at you in the Gulf wouldn’t you prefer to shoot a whole bunch of HE CVT-Frag at them?
I’m no ballistics expert, but it would seem to me that with such powerful hypervelocities, the transition between direct, and indirect fire would be well beyond the horizon.
With the horizon inside of direct fire range, would the horizon itself act as a terrain shadow? Much like a large hill creates a zone where conventional artillery fire cannot engage.
Yes sir,
That’s the deal. The distance to horizon of the earth curvature is simple. At sea level it is about 7 nm. 25 nm is well over the curvature of the earth. Doable with powder and shot. Not so much with raygun type effects. If they come up with a SADARM version of railgun pellet, perhaps but I’ve seen nothing in the literature about even going there.
Can one even imagine the ballistics of lofting a pellet exoatmosphere oriented “up” stalling and falling to earth into totally unknown winds aloft, atmospheric density unknown and expecting to hit a continent much less a ship? It will stall and then tumble. It’s then an unguided projectile.
Pretty silly really.
Well there’s no reason you couldn’t dial down the muzzle velocity, you just don’t send as much current through the rails and/or coils. That means you couldn’t rely on purely kinetic effects, but the accelerations would be low enough that you could use exploding shells. The only question would be EM resistance for the fuzes.