It's all go in the world of hypervelocity railguns this week. Following Friday's 33-megajoule test shot carried out at a US Navy laboratory, it has also been announced that a different railgun known as "Blitzer" has recently carried out firings which suggest that it is almost combat ready. The Blitzer comes to us courtesy of …
for 3 millisec
From info above it takes 3 msec to reach mach 5 at 60K G's. Give it enough mass (relative to the projectile) and a suspension system and it shouldn't be too hard to keep it sufficiently still during that time. Dealing with the reaction from the acceleration force is hugely greater than any issue with motion of the platform, is my guess.
I understand your reasoning but I have some objections.
Normal guns have a steel barrel, that confines the projectile. I read somewhere that big gun barrels suffer from some degree of deformation while shooting, as gyrostabilizers and antivibration mounts don't filter out everything. AFAIK actual railgun prototypes don't have any element for this role of physically constraining the projectile in a given path, leaving this part to the magnetism from the coils. My take is that the projectile, subject to lateral forces, would exert a huge pressure against the coils, and probably cause lots of heat in the process. And of course any physical contact with the coils themselves would destroy them, and probably the projectile and the weapon.
And let's not forget that the acceleration this weapon provides is an order of magnitude bigger than that provided by naval guns, and the -ahem- barrel, is longer, providing yet more torque.
And then there are 'battle conditions'. To be employed safely this system seems to need a ship in perfect conditions, something you don't usually find at a true war.
I'm no expert in the area, just an anonymous armamentaphile, so I could be totally wrong, but I have genuine doubts about this system's ever working in a batleship.
On the other hand, a land based railgun... mmhhhh... sounds great! :)
I see your points, but I think you're overestimating the level of vibration weapons systems can be exposed to on a ship. Certainly it's probably no more than you'd get in a tank, although I'd imagine a static artillery piece may be better.
At 2.4m I don't think it's longer than many large calibre naval guns.
Having said that there's definitely a lot of work to do before it's a viable weapons systems, but then the first jet engines and guided missiles weren't that good either.
It's a railgun, not a coil gun.
The projectile rides through the barrel along a pair of rails, maintaining physical contact with them at all times. The acceleration is provided, via the Lorentz force, by the electricity conducted along one rail, throught the projectile (or it's sabot) and back along the other rail.
So, yes it does indeed physically constrain the projectile.
Or maybe they will look to space and build an orbital bombardment package ??
I can see you whoooosshh bang
not even time to finish the beer
Mach 5 may seem fast enough to hit an aircraft but the maths says that it isn't.
Consider a threatening aircraft with an anti ship missile say 20 miles away.
If (having solved all the above problems) you fire a mach 5 projectile at that aircraft, it still has a a rather gentlemanly 20 seconds to decide to be somewhere else.
Assuming it it is ambling at no more than mach 0.9 it has about 7 miles of possible lateral positions and over 3 miles of height to consider as the projectile races towards it.
There are going to be a lot of misses. A lot
@Pointless: The Same Argument Can Be Made Against CIWS
An ASM only one kilometer out from the ship must be tackled by Mach 3 slug from CIWS. The ASM has one second to jump 10 meters to the left, right or up. If high enough, down.
The Russkies and others are clearly capable of moving a device 10 meters per second from no movement at all. Those who don't believe, look at the S-400 and ASTER videos on youtube.
An interceptor like ESSM can correct its trajectory not just to compensate for wind and irregular fuel burnoff, but also for the movements of the incoming projectile/missile until the last few milliseconds. IR, Radar and ESM sensors and software will do that.
If the projectile is unguided, software can calculate an intercept path and perform hit-to-kill. That's how SM-3 intercepts ballistic missiles. If the incoming "thing" is manoeuvring, ESSM will detonate its fragementation warhead and (hopefully) put at least one fragment into the "thing", thereby triggering the destruction of "thing".
I am not "in the know" regarding ESSM software's hit-to-kill capability, but there is no reason why it should be impossible to create it.
So maybe frigates will in the future have to house not just ESSM with fragmentation warhead, but also ESSM with a solid Uranium or Tungsten block for optimal hit-to-kill.
Actually rather a narrow cone...
If it wants to hit the ship that is.
Hitting the missile is the main target, should the plane get in the way of a hypervelocity slug then that's just bonus points.
Planes dont tend to carry many antiship missiles at a time, soo 2 harpoons and a kamikaze run?
Thats a lot of effort...
just to kill people, isn't it?
That hasn't stopped people in the past.
Just because it's more complicated doesn't mean people won't want to use it.
Guns (especially flintlocks) are more difficult to use than bows and arrows, slower too - but we're not going to village greens on Sundays anymore are we?
Hitting people and things with rocks has always been a popular way of getting your point across - all that changes is the size and speed of the rock.
Grenade is a sort of rock...
It would be a lot of effort to kill people, but it's not about killing people. It's about providing high-paid jobs in the weapons industry. No one involved gives a toss about what it's all for, or even if it ever works in practice. As long as it jumps through the procurement hoops for the next tranche of money everyone's happy.
"Guns (especially flintlocks) are more difficult to use than bows"
Guns dont require as much muscle power, therefore cheaper to feed the grunts grain as opposed to good red meat.
And having fired guns, bows and used a sling, bows are far more difficult to fire accurately than guns, slings an order of magnitude harder again.
the musketeers are much easier to train than archers (go ask the sealed knot or other re-enactment group) to a usable standard, and dont forget it is easier to mass produce a gun than a english yew longbow.
Actually, I'm better with a bow (recurve, none of them new fangled compoung thingies)
than a gun, didn't take all that long to become proficient with it either. Never tried a sling. Now what a gun does give you is longer range. These days, they are also a fair bit quicker than a bow as well. Last time I checked bows and rifles cost about the same at the local sporting goods store. Well, the ones worth owning at least. You can get those cheapy bows they use at summer camp for far less than a decent one.
I'd lay bets you have put in a lot more hours on the bow than you have with a rifle though?
An 11 kg projectile at Mach 5 delivers a 1.79 MW splatter
" GA is .. under contract to develop an Advanced Containment Launcher .... in 2011. These objectives include a launcher capable of .... muzzle energy of 32 MJ ( .... to support a 110 nmi mission) with muzzle velocities of 2.5 km/sec. This launcher involves the development of technologies appropriate for fielding tactically relevant containment with a bore life that exceeds 100 shots." A pretty picture of a bird's-nest-butted barrel accompanied.
So, they are having the same Rail Self-Destructo problems the navy guys are...
ps: welcome to our bear-aware continental defense observer. " sloppiness is faithful " works at so many levels.
Hmmm my psychic balls tell me...
Yeah this thing is BIG.... just the barrel part, that can be made to rotate independently with all the capacitors etc., in the hull..... but It's leap of figmentatious proportions, just like talking to my balls, to be able to knock out a few slugs in rapid succession, in different directions and in the case of misses etc...
It's also nice how when the US NAZI govt spits chips about it becoming common knowledge that their sleazomats are calling other folks piss pots and idiots, and her they are putting "Hmmmm blow up the images, measure with a micrometer, and do a simple reverse engineer" details up on the web of their super weapon....
6 months the Chinese will have a better one at half the price.
Aircraft & sea skimming missiles?
Dont really represent a significant threat, some time ago there was a sign in the Phallanx maintenance department stating "If it flies, it dies" & it sure did.
I've been hearing some of these "sprinting" missiles can do some pretty wild turns on approach and still hit target. Is this an exaggeration or does a CIWS have a means to compensate for such a weapon?
@N2: And You "Downed" an Incoming SM-3 and a KEPD ?
I guess not. You downed that ridiculous little fast propeller thingy.
Should be posible
The interesting question is how fast it can shoot again in case the first one missed, it won't be much use if it can't reload/recharge fast enough.
Now, make it small and potable (quake style weapon) or give us sharks with laser on their heads.
It may not have to be that fast...
...if it operates as part of a tandem pair. Either way could offer advantages. A staggered firing would provide a better opportunity to harass a target with a stream of rounds, while a simultaneous fire might be of help against more elusive targets--each could help the other to nail it even if it wanted to move.
But why would you want to drink
a rail gun?
Sabot - friendly fire?
Wouldn't want to be ANYWHERE half a mile in front of that bugger if there's a discarded sabot travelling at Mach 5 heading my way!
Rail Gun accuracy
Given the US reputation for 'blue on blue' I suspect any guidance system will be for show only.
Why This Technology Is Not A Satellite Space Launcher
First Reason: Too slow (Mach 8, Mach 23 Required)
Second Reason: Aerial Friction in the lower atmosphere is gigantic at Mach 23. (or just Mach 8). Note that you must launch more or less horizontally, because that is the direction of the velocity vector you need for the satellite.
Third Reason: The Launchpad needs to be 41kms long !
echo "scale=20;(9*10^3)^2/(2*100*9.81)" |bc
(assuming that your satellite (antenna ? semiconductors ?, gyro ?, heatpipes ?) can actually stand 100gs, as the "smart" S-400 missile can)
Fourth Reason: I don't think they are able to shield the extremely sensitive electronics of the satellite from the gigantic magnetic fields and resulting currents. Shielding magnetic fields is much, much tougher than shielding electric fields.
So you're saying it fails at doing something it wasn't designed to do? That's like saying a tank fails at being a jacuzzi. Nowhere did the article or GA say it was a satellite launch system.
"FAIL" was directed at
Re: as a space launcher
In addition to the previous reply, I would note that you've replaced the 60000g of the article with a figure 600 times smaller. There are useful payloads that can withstand that (like fuel and water) so if you really only need a 100m railgun to put stuff into orbit then you can be sure that the DARPA types are looking into it.
On the other hand, air resistance is what we currently use to *slow down* a craft moving at orbital velocities, so what ends up in orbit might be a hot barrel of tea. Too hot for coffee, so I imagine the Yanks won't pursue the project.
Contest: name the ship carrying this weapon.
Up to 5 suggestion per post.
1- USS Stonethrower (or HMS Bouldertoss for UK, hehehe...)
2- USS Gauss
3- USS Crossbow
4- USS Flintlock
5- USS Ballista
Ok I'll leave when we make port.
*Crafty Attack From Behind With A Brick
USS Valley Forge
Damn, I gotta get me one of those . . . .
As others have noted, Mach 5 with 60,000g means a ~2.4m barrel and ~3ms firing time. That's feasable for low/moderate sea states as any shock to the hull is unlikely to coincide with the instant of firing.
Making the projectiles "smart" is a non-starter. The forces involved in the launch would crush all but the simplest and hardest electronics, would likely bend/break movable fins, and might even detonate the warhead. On top of that, it's going to be enough of a magnetic field (presumably on the order of 1 Tesla, like MRI scanners) to induce enough current to fry electronics and seriously limit the materials that can be used. In addition, it's non-trivial even to steer something at mach 5 - the air has the consistency of a brick wall.
Under-sea blasts work fine for torpedos with a ton of high explosives. This sort of hittile would be maybe 1kg, with a muzzle energy of ~1.5MJ. Water has a specific heat capacity of 4,187J/kgK and a specific latent heat of evaporation of 2,270,000 J/kg. Assuming a sea temperature of 15 deg C it will take over 2.6MJ to boil 1kg of water - in other words, at 100% efficiency of conversion, the KE would be enough to boil only about a pint of sea water, which really isn't going to snap the keel of any ship that wouldn't fit in a bottle.
As an anti-ship weapon, it's going to be limited to perforating the hull and hoping to hit something that'll go "boom". With a decent ROF and a lot of cheap shots, that could still be useful, but it's got to compete with 4.5" guns that can deliver a couple of dozen shells a minute out to 12nmi.
Against Vampires the speed is a significant advantage as it means you can engage further out, which means that any deflection is likely to make the incoming ASM miss the target. While it's possible for a missile to jink to the side to avoid countermeasures, that takes a lot of energy, and it takes a lot of energy to correct the trajectory again afterwards - and so there's a finite limit to what can be done. Of course, you're firing a small, dumb dart a very long way - easy to miss a moving target the size of a phone box at several miles.
Sadly there is one target which this weapon is ideal for use against: the SR-71 'Blackbird' :(
Hmm. there are some mechanical challenges I can see on the horizon (yes, right next to that incoming missile). I'm going to be very interested how they will fight the resulting torque if they have to fire perpendicular to the ship's axis. Given the rather impressive acceleration forces it strikes me that this will generate enough torque to make the launching ship rotate along its length axis like a canoo. You need some *serious* water displacement to buffer for this.
Rather good for comedic effect, not so good for maintaining a defensive position.
Just musing - I'm sure someone must have though of this but I found no mention of it yet. Anyone?
Forget Smartness For Now
No need for smart projectiles if you can get the guns to recycle ready to fire quickly and for a decent number of firings before needing service.
Get a few railguns that can sustain a good rate of fire and do so for more than a few rounds and instead of one projectile (possibly) hitting the target at Mach 5, you can populate the general area of the target ship with lots of projectiles travelling at Mach 5 and (possibly) rip the thing to shreds.
Or in the case of hostile aircraift/missiles significantly cut down or eliminate the number of options they have to course correct away from the threat. I think this was what Tool of Lucifer was saying in the first part of his rant.
Personally I like the idea of railguns, they make me happy. But I can't help wondering what happens to the projectiles that miss as 200 miles is a long way to travel... Potentially into civilian coastal settlements.
Maybe smartness is needed after all.
In a galaxy far, far away....
Anyone else sensing that the Star Wars project might be still kicking and screaming somewhere in a back office in the Pentagon? High efficiency solar panel advances, rocket propulsion that uses minimal fuel and hyper velocity railguns seem like a good combination of technologies to shoot rockets out of the sky or even flatten military targets without sending in the boys in green (or tan brown in the current theatre).
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