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from the is-that-a-railgun-or-are-you-just-happy-to-see-me? dept.
The Motley Fool's Rich Smith writes:
For more than three years now, I've been tracking the U.S. Navy's progress toward building a working electromagnetic railgun prototype — a Mach 6 cannon reputedly capable of striking targets 110 miles away with pinpoint accuracy.
Each railgun projectile would cost about $25,000 to produce — and if you're keeping track, then yes, success on the railgun project would yield a weapon boasting nearly twice the 67-mile range of Boeing's (NYSE:BA) Harpoon II missile but costing just 1/48th the Boeing missile's $1.2 million cost.
https://www.fool.com/investing/2017/04/22/navys-new-mach-6-em-railgun-almost-ready-for-prime.aspx
Electromagnetic Railgun - First shot at Dahlgren's new Terminal Range https://youtu.be/Pi-BDIu_umo
(Score: 5, Informative) by Runaway1956 on Thursday April 27 2017, @01:51AM (23 children)
The gun is impressive, in that it puts massive energy downrange. But, being rather conservative in nature, I'm wondering WTF the Navy is willing to build an entire ship around this new weapon. The questions asked above about the life of the barrel are spot on.
Take Ye Olde Reliable 5 inch 54 caliber gun from the Adams class of destroyers. In one "Mad Minute", our two guns could put 60 rounds in the air before the first one splashed, and/or hit the target. Sustained fire wasn't that fast, but the guns were rated at one round every two seconds, and a fresh crew could achieve that rate of fire for a minute or two. Tens of thousands of rounds could be pushed through the tubes, maybe even hundreds of thousands, without significant wear. OK, so the range was only out to the horizon, give or take a bit, but we could hammer away at a target for hours, literally, without damaging our guns. Days, if necessary. Longer if a supply ship were standing by to replenish depleted stocks. Bear in mind that our shells might be HE, antipersonnel, armor piercing, anti-aircraft, or just an inert lump of iron.
Navy should invest in one or two of these new guns, and test them. NGFS (Naval Gunfire Support) for about three months, if the guns survive that long, then sure, start buying more. If the damned things only last a couple days, or a couple weeks, before accuracy degrades to, "Well, we can still hit the earth", then we're doing things all wrong.
I place little faith in the damned fools who have signed off on that Zumwalt POS and the F-35. With "leaders" that damned stupid, I don't expect them to make intelligent decisions about ship's weapon systems.
At this point in time, at this stage of development, putting a single rail gun onboard a cruiser, while keeping a pair of conventional 5 or 8 inch guns as mains seems the best way to go. That way, you get the proven reliability and versatility of powder based cannon, while gaining the chance to reach out further with the new technology.
Ships, historically, haven't relied on a single weapons system. The Adams class I mentioned had two guns, one missile launcher, two sets of torpedo tubes, ASROC, and small (.50) machine guns. Starting with the Arleigh Burke class of destroyers, ships were built with a point defense system because ship killing missiles were becoming a real threat. (Rest in peace, HMS Sheffield and crew.) No one puts their faith in a single system - why start now?
Oh - the discussion of pinpoint accuracy? If I'm lobbing something with enough energy to create a five meter crater in the ground, and I can put that round inside of that five meter circle at a range of 20 miles, that's "pinpoint" enough for my purposes. While the term may be technically incorrect, soldiers and sailors aren't generally concerned with civilian meanings of words. Look at it from the point of view of the target. You're on a mountainside, with a beautiful view of the ocean. We come into view on the horizon, steam in towards shore, and put those 60 rounds into the air that I mentioned in the first paragraph. How many of them are going to actually hit you in the face? Probably none - but they'll all land close enough to kill you. Achmed the Terrorist's wet dream, right? "I keel you sixty times!"
(Score: 2, Informative) by qzm on Thursday April 27 2017, @02:41AM (2 children)
So, perhaps you would be so kind as to give YOUR estimate of pinpoint for a passive shell, at mach 6, over a 110 mile range through atmospheric conditions?
My estimate is 'will probably hit the small town it was aimed at', but 'will certainly not hit the large building it was aimed at'
I will back that up with a little maths. IGNORING atmospherics (which would have an order of magnitude more effect at least)
110 miles is just under 180000 meters.
The 'shell' looks to be well under 1/2 meter long.
Its trajectory will be 90% defined by the last 1 meter (2L) of barrel it travels through (actually less, but makes the maths easier)
So, to hit a target of 5m radius, that last 1 meter must have a deviation of less than 5/180000, or around 28um. (0.028mm) from perfect alignment. At these kinds of energy levels? not a chance.
But worse, given a 10 meter barrel (eyeballing that, longer makes it worse), to even aim that accurately means we need a horizontal rotational accuracy significantly better that one part in 2,200,000, including recoil, etc. not a chance.
Vertical alignment is much MUCH more stringent.
So, no, non guided ordinance is never 'pinpoint accurate' at 110 miles.
Atmospherics, of course, make that much Much MUCH worse, and basically make it a joke (and no, the high velocity doesnt make it easier, at mach 6, locally varying atmospherics density will have huge effects).
So, I go back to my claim. At 110 miles It will hit the town it was aimed at, but probably not the building.
(Score: 2) by Runaway1956 on Thursday April 27 2017, @02:27PM (1 child)
In flight correction. The video I watched shows the projectile adjusting it's flight near termination. I have little idea whether that in flight guidance can be triggered earlier, it appeared that guidance took over in the last - ohhh - 5 to 10 miles or so. The antiaircraft projectile surprised me, in that, the main projectile isn't expected to hit the target. Instead, the main projectile opens, and scatters a wad of smaller projectiles, rather like a shotgun. (I watched four videos last evening before work, please don't ask me to retrace my steps for links.)
From what I saw, hitting a large building in a city 100 miles away is only a minor challenge. It is conceivable that a well trained crew can put that shell into the first floor, and they might even be able to choose which window it enters through. Unless I completely misunderstood what I was watching, these projectiles will have guidance only slightly less sophisticated than today's cruise missiles.
And, regarding the size of that crater. Our 5" 54 guns would leave a 5 meter crater in the ground. The USS New Jersey's main guns would carve out a crater about 30 yards, or meters, which are close to each other for "government work". The rail gun probably exceeds the 16" guns in that respect . . . .
Looking for links to compare total energy of the three guns, found this article which echoes some of our comments here: http://www.popularmechanics.com/military/weapons/a21174/navy-electromagnetic-railgun/ [popularmechanics.com]
This is more what I was looking for: http://www.popularmechanics.com/military/weapons/a21174/navy-electromagnetic-railgun/ [popularmechanics.com]
Railgun delivers 64 megajoules on target, while a BGM-109 Tomahawk cruise missile delivers 3000 MJ. The sentence I was looking for is this one: "A MK 8 round fired from the 16-inch guns of an Iowa-class battleship at 2,500 ft/s (762 m/s) has 356 MJ of kinetic energy at the muzzle."
Obviously, my presumption that this railgun projectile would compare to New Jersey's guns was wrong, wrong, wrong. The railgun will maybe deliver a little more destructive energy at the sharp end of the stick than our 5" 54's did.
You make good points, and ask good questions - thank you. You made me look a little harder to make valid comparisons. :^)
(Score: 0) by Anonymous Coward on Friday April 28 2017, @04:14AM
this is an exemplar of why i am displeased when persons disparage eth_funked and runaway1956 in the same sentence. One is 99% troll, the other is a person of occasionally malleable belief and rationale who looks things up for the community sometimes.
(Score: 4, Informative) by Zipf on Thursday April 27 2017, @02:53AM (16 children)
My understanding is that the shell is guided and can explode at target distance to create high velocity debris field.
(Score: 0, Troll) by Anonymous Coward on Thursday April 27 2017, @03:50AM (8 children)
You've contributed an actual fact to correct "know it all" Dumbass and his extensive math who was totally ignorant that even "non engined" ballistic projectiles are guided these days. (Movable steering fins plus guidance such as GPS.)
You get less informed by reading comments on Soylent more often than not. :-(
(Score: 1, Insightful) by Anonymous Coward on Thursday April 27 2017, @06:27AM (3 children)
I want so bad to mod this up for the :
but why do we have to denigrate someone who posted in good faith but may not have understood?
I appreciate the addition of additional information, or more correct information, but its also saddening to see a verbal flamebait launched against a fellow Soylentil that was posting that which he was aware of.
Places me in one helluva quandary... is this informative or flamebait? I guess the two cancel out. So I will reply instead.
(Score: 0) by Anonymous Coward on Thursday April 27 2017, @06:54AM (1 child)
but why do we have to denigrate someone who posted in good faith but may not have understood?
You must be new around here, ain't ya? We have to denigrate because it is Runaway1956-2666, he posts on everything, especially things he knows nothing about, constantly. It is not in good faith, it is a bad case of logorhea. And he claims to have been a sailor, but inquiries with the DOD report that no one named "Runaway1956" ever served in the US Military, ever.
Oh, wait, you were talking about someone else? Oh, well, carry on then.
(Score: 0) by Anonymous Coward on Thursday April 27 2017, @08:39AM
I'm pretty sure his real name is not "Runaway1956" or even just "Runaway". My real name isn't "Anonymous Coward" either (and nor is yours, I guess).
And I'm pretty sure the military would require you to use your real name.
(Score: 2, Informative) by qzm on Thursday April 27 2017, @07:19AM
Just to add a little more 'fact' to these boys need to fantasies about this actual weapon.
What they are dreaming of is the 'hyper velocity projectile' project, which the navy has been chasing for some time.
So fact it has achieved exactly one thing, the firing of a solid dummy load, with no active capability.
The HPV has been a dream for a few generations now, but still there is no actual evidence that it is actually possible.
After all, they only have to be able to receive GPS and radio guidance through the plasma sheath generated at mach 6+, in a unit a
small fraction of the size of existing guided munitions, and control its hypersonic flight.
And of course make that hold up in the 100,000+G acceleration of these guns..
should be ready just as soon as they find that bad of unobtanium they left in the back of the lab.
Damn those facts.
(Score: 1) by qzm on Thursday April 27 2017, @06:59AM (3 children)
Good to see 'My understanding is that the shell is guided and can explode at target distance to create high velocity debris field' is a fact!
Of course there is no evidence *I* can find of either of these 'facts', care to present any?
Thought not.. time to come back from some scifi future and stick to actual facts.. even if real math confuses you.
(Score: 0) by Anonymous Coward on Thursday April 27 2017, @10:21AM
How would you present evidence of 'my understanding is'? A brain scan, maybe?
Note that the fact that something is Zipf's understanding doesn't necessary mean that the something is correct; Zipf correctly stated it as his understanding. The assumption that someone's understanding has to be in any way related to reality may generally be reasonable, but it still remains an assumption, unless you can support that assumption with facts.
In other words, while you are right to criticize Zipf for an understanding that is not backed up with facts, you are not right with your accusation of Zipf claiming wrong facts unless you have any evidence that what Zipf writes is not Zipf's (flawed) understanding, as that is the only thing he claims as fact.
(Score: 3, Informative) by SunTzuWarmaster on Thursday April 27 2017, @12:32PM (1 child)
Um... There was the article in Popular Mechanics from last year (http://www.popularmechanics.com/military/weapons/a21174/navy-electromagnetic-railgun/)... Also reports from Fox news describing navigation sensors within the projectile (http://bgr.com/2016/03/17/futuristic-military-railgun-bullets-could-travel-at-mach-6/).
Of course - you could always just consult the spec sheet (and advertising page), from the manufacturer:
http://www.baesystems.com/en-us/product/hyper-velocity-projectile-hvp [baesystems.com]
The HVP’s low drag aerodynamic design enables high-velocity, maneuverability, and decreased time-to-target. These attributes, coupled with accurate guidance electronics, provide low-cost mission effectiveness against current threats and the ability to adapt to air and surface threats of the future.
It is hardly a secret.
(Score: 2) by Scruffy Beard 2 on Thursday April 27 2017, @06:48PM
For the baesystems link, I get:
404 Not Found
404 Not Found
* Code: NoSuchKey
* Message: The specified key does not exist.
* Key: en-us/product/hyper-velocity-projectile-hvp
* RequestId: 90007EDB0A1AF376
* HostId:
vX9frjxmyD/l0vcvbY0YNDT5ZAjGYtETmEfUPNJE4eoT8hnwaow6ue4JtpyrwHKjDJl
2E/AfFm8=
Not sure if it is because I was trying to access from outside the US.
(Score: 2) by Azuma Hazuki on Thursday April 27 2017, @04:16AM (4 children)
So the purpose of this thing is to do what exactly? Basically to be a 7500km/h fragmentation grenade? I know KE = 1/2 m(v^2) and that that ^2 adds up fast, but I'm not seeing how this is going to work. Wouldn't it do more damage by burrowing itself into the ground and making subsequent blast, heat, and shock waves, like a small meteor strike?
I am "that girl" your mother warned you about...
(Score: 0) by Anonymous Coward on Thursday April 27 2017, @05:47AM (3 children)
You can't explode the projectile AFTER you crash it (and attempt to "burrow", as you call it).
Maximum damage is delivered by exploding the thing ABOVE the target so the blast is transmitted to a larger area beneath it.
(Score: 1, Insightful) by Anonymous Coward on Thursday April 27 2017, @08:27AM (1 child)
I guess that depends on your target. I guess if you target a closed structure, there's value in first breaking through the wall, and then exploding inside, in order to destroy as much as possible there. If exploding outside, the structure will provide protection; if exploding inside, the structure will instead prevent the destructive energy go wasted outside.
(Score: 2) by Runaway1956 on Thursday April 27 2017, @02:37PM
You have nailed the definition of "armor piercing" precisely. When a tank is hit with an armor piercing charge, the projectile doesn't enter into the tank at all. Instead, the projectile sets off the internal shaped charge, which is very precisely aimed at a point maybe half as big around as a pencil. The plasma created in that shaped charge burns through, and enters the tank, then ricochets around inside of the steel hull. Anything the plasma touches is toast, whether it be electronics, ammunition, the tank commander, the tank driver, or the pinup taped beside the gunsights.
Most definitely, often times, you want to deliver your destructive energy INSIDE of a target.
(Score: 1) by pTamok on Thursday April 27 2017, @11:25AM
Umm.
Tallboy. https://en.wikipedia.org/wiki/Tallboy_(bomb) [wikipedia.org]
Grand Slam. https://en.wikipedia.org/wiki/Grand_Slam_%28bomb%29 [wikipedia.org]
Ok, bombs rather than shells, but designed to penetrate metres of concrete and then explode.
Lets try armour-piercing shells, a staple of tank warfare: https://en.wikipedia.org/wiki/Armor-piercing_shell [wikipedia.org] - APHE designed to penetrate, then explode.
Or, how about Palliser shell: https://en.wikipedia.org/wiki/Palliser_shot_and_shell [wikipedia.org] , the largest of which, I believe massed 910 kg with a 14.5 kg bursting charge.
It appears one can explode a projectile after one crashes it.
(Score: 2, Insightful) by qzm on Thursday April 27 2017, @06:56AM (1 child)
Great, care to post any evidence of that?
*My* understanding, based on all the available test information on this actual device is that it fires completely passive ordinance.
There would be significant issues is developing active ordinance for this, due to both the huge accelerations involved (much higher that existing guns),
and the small issue of the massive electromagnetic fields that are an essential part of its basic operation.
So, anyone care to provide one small shred of evidence of a guided shell? We have seen images of the proposed shell, and have an approximate scale of
18 inches by 'several inches' round..
But since people here dont like facts, here are a few more.
We also have a price, of $25k per round. The Zumwalt was SUPPOSED to have guided shells, and they were priced at $800k each.. There is a cheaper
howitzer guided round, much shorter range and MUCH lower accelleration capability, at 'only' 68k each.. Those guided 25k rounds are a steal! (not to
mention that those howitzer rounds are 155mm... a little larger...)
Of course they are going to have to fit in a rather small package, and work at mach 6.. with GPS reception.. I'll leave that little bit of thinking up to you.
so come on, lets see your evidence of these mythical guided rounds?
(Score: 1, Informative) by Anonymous Coward on Thursday April 27 2017, @07:28AM
There would be significant issues is developing active ordinance for this, due to both the huge accelerations involved (much higher that existing guns),
and the small issue of the massive electromagnetic fields that are an essential part of its basic operation.
Not just massive magnetic fields. This is a rail gun, not a coil gun - the projectile is a part of the circuit, and there is a ton of power being put into that circuit. It's basically a single loop electromagnet, consisting of two rails connected by the projectile.
The amount of heat involved is also enormous, both from the electrical power and from the Mach 6 speed.
(Score: 2) by bob_super on Thursday April 27 2017, @05:29AM
To be fair, "Well, we can still hit the earth" a hundred miles away, might be considered a decent achievement for a Blue Water ship.
I don't think anyone is suggesting that the railgun would be the only toy onboard. But one of the points of creating the all-electric multi-billion-dollar Zumwalts was to enable these futuristic MegaWatt weapons (lasers and railguns).
It's already a weird thing that doesn't seem to fit its official purpose (or category size) well, if they don't put a new weapon on at least one of them, they will have a big credibility issue for the next round of futuristic designs...
(Score: 0) by Anonymous Coward on Thursday April 27 2017, @04:19PM (1 child)
OK, so the range was only out to the horizon, give or take a bit, but we could hammer away at a target for hours, literally, without damaging our guns.
This underplay the key problem with your argument. My understanding is that combat is all done over-the-horizon now, so having a gun which shoots only to the horizon is useful, but far from comprehensive.
I could just as easy say, "forget your hugely expensive guns, with a combat knife a ship could kill infinite people at arms reach. You don't even need no supply ship, so there is further cost savings there."
(Score: 2) by Runaway1956 on Thursday April 27 2017, @05:16PM
I don't object to the concept. I object to building a ship around an unproven weapons system. I would heartily approve of a ship being built with on powder cannon, and one rail gun. That ship would gain all the capabilities offered by the rail gun, while retaining the proven reliability of the venerable 5" cannon. If the new-fangled gun proves to be a failure, then the gun might be re-engineered, and made reliable. And, if that were to happen, the ship in question would still be able to fight while waiting for the Pentagon to decide how to proceed. Worst case in this scenario, they dump the railgun, and mount another cannon in it's place. Best case, the railgun is successfully re-engineered, upgraded, and the ship returns to action - again with one of each guns, just in case.
Just for an example of "failed" marine technology - 1200 pound steam boilers. The Navy used 600 pound steam for almost forever. Some bright boys decided that if 600 pounds is good, then 1200 pound should be twice as good. My second ship was a Garcia class frigate, with 1200 pound steam. It was a complete POS. In any real ship-to-ship combat, we would have been the first casualty, because the fire was snuffed so easily. When the fire went out, we were dead in the water, at anyone's mercy. Meanwhile, my first ship only dropped the load in the boiler room ONCE in the 2 1/2 years I was aboard.
After building two or three of those 1200 pound boiler ships, Uncle wised up, and put everything back on 600 pound.
Garcia class ships had one, and only one, redeeming feature. For it's day, it had the most powerful computers available, and could coordinate fleet wide fire control, which also meant we were in charge of tactics. Strategy came from fleet command, whether a carrier, a commodore, or maybe even from the pentagon, but tactics were our specialty.
Fat lot of good that was, when we couldn't keep our own fire lit . . .