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| Science & Technology |
| Return of the Dreadnaught Era? |
| 2010-12-29 |
| The US Navy, continuing its quest for a hypervelocity cannon which might restore the big-gun dreadnought to its lost dominion over the seas, has carried out a new and record-breaking railgun test. This latest trial firing pushed muzzle energy to a blistering 33 megajoules (MJ). The muzzle velocity, as in the previous 10 MJ test in 2008, was still approximately Mach 7.5, but the heavier projectile used this time carried much more kinetic energy: approximately enough to strike targets 100 miles away in an operational weapon, according to the Office of Naval Research (ONR). The ONR wants to achieve lab trials at 64 MJ, potentially offering 200 mile range with projectiles striking at Mach 5, before trying to build an actual weapon. A railgun works by passing vast amounts of electricity from one rail to the other via an armature linking the two: this generates a huge force driving the armature down the rails and out of the end of the gun. The armature can be the projectile itself, attached to it, or may be a sabot which will drop away once the slug is flying free. The technical challenges of building railguns are many. Not least among these is the generation of very brief pulses of extremely high electrical power (the armature's run along the rails, even if they are quite long, is necessarily over very quickly – so the gun hasn't got long to put poke behind it). Then there's the matter of making rails that won't be destroyed by the armature screaming along them, which is yet to be properly sorted out (at the moment, the ONR only trusts its railguns to survive two or three shots before being knackered). Assuming that the various issues of building a railgun can be solved, one must then deploy it to war and find power for it. About the only mobile platform able to supply the vast amounts of electricity required for a combat railgun is a warship, so it's no surprise to find the navy rather than the air force or army looking into this. Not only would a 64 MJ railgun permit a warship to pound targets far away below the horizon with unstoppable Mach 5 hypersonic hammer blows, lesser hypersonic cannon might also sweep the skies of pesky, merely-supersonic aircraft and missiles. Ever since the Battle of Midway, sailors have reluctantly been forced to accept that it is aircraft (and nowadays missiles) which win battles at sea, not ships: generally speaking it is also aircraft which permit navies to directly influence events ashore. The aircraft carrier long ago supplanted the mighty big-gun battleship as top naval dog. But railgun warships might put an end to this, swatting down ship killer missiles or attacking aircraft from afar with ease and splattering targets ashore quickly and responsively – no need to keep aircraft on station or wait endless tens of minutes for a subsonic cruise missile to cover the distance. The only way to deal with a railgun dreadnought – just as in the days of old when the first armoured all-big-gun battle wagons appeared – would be by using a ship just like it. Surface warships and surface-fleet officers, once again, would rule the seas and the naval roost. Apart from all that, another major advantage would be on offer for navy logistics. Rather than troublesome missiles or shells crammed with explosive warheads and propellants, the supply chain would only need to handle inert projectiles and some extra supplies of fuel for the ships' engines. Railgun warships would be less prone to blowing up when hit in combat, too. So it's all good, from a naval point of view. But the ONR has many hills to climb yet before their new technology is an actual functioning weapon rather than a one-off laboratory test rig. The new Royal Navy Type 45 destroyers, the first warship class to use electric transmission for main full-speed propulsion, can supply a bit more than 40 megawatts of electricity. If fitted with one of the US ONR's desired 64-MJ railguns, they could recharge it for another shot in a little over a second and a half, though this rate of firing would leave little juice for propulsion. At the other end of the spectrum, a US Navy Nimitz-class supercarrier has twin 550-megawatt nuclear reactors (though it doesn't use electric transmission and so can't deliver this in the form of 'leccy). A railgun dreadnought built to the same outrageous scale would be able to ripple off 15 irresistible Mach-7 thunderbolts every second and still maintain steerage way. |
| Posted by: Anonymoose |
| #19 Imagine a shotgun type load instead of a sabot. You wouldnteven need super exact aim just straddle the target. You might not kill the target but a single hit, even a smaller round, is gonna hurt. And itmight look like some kind of meteor shower. |
| Posted by: Rjschwarz 2010-12-29 22:54 |
| #18 a virus designed in at the factory Which is not SF, gromky? |
| Posted by: g(r)omgoru 2010-12-29 16:56 |
| #17 None of this matters when all the computers on your ship stop working in the middle of combat due to a virus designed in at the factory. That's the future of armed conflict, not sci-fi superguns. It is both, actually gromky. In fact, a jamming swarm of small robots coming at your ship and broadcasting to overwhelm the firewall and WIFI systems and insert their malicious code is also a very workable weapon. A sub coming under a ship and quietly planting a hub spike to do the same thing is also an option. Blowing the hell out of something with a sci-fi gun and taking over computers are both in the future. |
| Posted by: DarthVader 2010-12-29 16:33 |
| #16 None of this matters when all the computers on your ship stop working in the middle of combat due to a virus designed in at the factory. That's the future of armed conflict, not sci-fi superguns. |
| Posted by: gromky 2010-12-29 15:56 |
| #15 "Or will everyone be building new versions of HMS Hood..."Christ, I hope not. The wreckage on the bottom of the Davis Straight ought to get that idea out of a lot of heads. Seriously I can see this going hand and hand with the Navy's continued interst in non-Tokamak style fusion reators |
| Posted by: Cheaderhead 2010-12-29 13:54 |
| #14 "Fear God and dread naught!" |
| Posted by: borgboy 2010-12-29 13:39 |
| #13 Could you hit a moving target, such as a tank, with a solid shot from an M5 gun forty miles away? No? That's correct. Then we're talking about hitting ships at a distance and aircraft closer in. Occasionally. Troop support is not included. With a 200 mile range, troop support will become important I feel. Not that it's a bad thing to be able to hit targets vulnerable to solid shot. But even something like a hardened Excalibur round wouldn't work. So accuracy without mid-course guidance or homing...? What, exactly, could you plan on hitting? Curiouser and curioser. Incoming missiles, swarm attacks (by torpedo boats over water), and pirates are part of it. But you could use it on troop and equipment concentrations on land as well as fixed targets. Extremely high velocity rounds taking less and less time to target reduce the chance of missing by reducing the time available for aiming inaccuracy to multiply to a miss. But that means being on target the first time. Anti-aircraft, maybe. Yeah. I'm thinking flak kind of stuff. Rail shotguns are the only thing I can think of that might be made to disperse reliably. |
| Posted by: gorb 2010-12-29 12:06 |
| #12 I don't think its so much the impact (which I guess is impressive) but the rate of fire. One every 2 seconds - even one every 5 would be devastating. What was the rate for those big guns on the Iowa class battleships? What is the rate-of-fire for a missle launcher? I wonder if you could put one of these on a sub... |
| Posted by: CrazyFool 2010-12-29 11:58 |
| #11 IIRC, the intent is to have a weapon that shoots dumb, solid projectiles - they rely on kinetic energy alone for their destructive power. They are also primarily intended for shore bombardment of fixed targets, rather than moving targets like tanks. The idea of shooting down airplanes and missiles seems like a stretch, too. The railgun itself will be fairly massive, and not too easy to aim at a fast moving target. |
| Posted by: Rambler in Virginia 2010-12-29 11:51 |
| #10 Would it be effective against bunkers? |
| Posted by: DoDo 2010-12-29 11:47 |
| #9 Let's presume we have a M5 proje weighing half a ton impacting in a terrain of dirt and a few rocks. Is a solid shot as good for anti-personnel/anti-armor as HE or dispersing submunitions? At that speed, everything near it becomes anti-personnel and anti-armor. Basically you have a meteor impacting at those speeds and everything near it gets vaporized by the heat/shockwave or a little farther away gets shredded by the debris. Second, can HE or submunis survive the accel of a M5 or M7 railgun? Depends on how much shock the HE is subjected to and how much heat is generated. But, as shown above a HE version really isn't needed at those speeds. |
| Posted by: DarthVader 2010-12-29 11:09 |
| #8 Gorb. Could you hit a moving target, such as a tank, with a solid shot from an M5 gun forty miles away? No? Then we're talking about hitting ships at a distance and aircraft closer in. Troop support is not included. Not that it's a bad thing to be able to hit targets vulnerable to solid shot. But even something like a hardened Excalibur round wouldn't work. So accuracy without mid-course guidance or homing...? What, exactly, could you plan on hitting? Curiouser and curioser. Extremely high velocity rounds taking less and less time to target reduce the chance of missing by reducing the time available for aiming inaccuracy to multiply to a miss. But that means being on target the first time. Anti-aircraft, maybe. |
| Posted by: Richard Aubrey 2010-12-29 11:09 |
| #7 Any electronics couldn't. |
| Posted by: gorb 2010-12-29 10:57 |
| #6 Let's presume we have a M5 proje weighing half a ton impacting in a terrain of dirt and a few rocks. Is a solid shot as good for anti-personnel/anti-armor as HE or dispersing submunitions? Second, can HE or submunis survive the accel of a M5 or M7 railgun? |
| Posted by: Richard Aubrey 2010-12-29 10:42 |
| #5 I doubt Bill Griling, that any armor could defend against such a weapon. Anyone with this ship had also be careful against planes, subs or rockets. |
| Posted by: Bernardz 2010-12-29 07:44 |
| #4 Just how do you armor a ship against a 64MJ round? Build it out of the equivalent of paper mache. I say bring back the Iowa class battleships if you want to sling really large projectiles. Retrofit them with nuclear reactors. You'll need something massive to not be tipped over by the reactionary forces involved. You could make some awe-inspiring area-effect weapons with this that would work great against incoming missiles, swarm attacks, and pirates. Even if you just shot it into the water right in front of the target. Rail shotgun, anyone? |
| Posted by: gorb 2010-12-29 01:36 |
| #3 Kool. How does one steer a hypervelocity inert object to the desired point of impact 200 miles away? More show than go, methinks. Of course when the munition has a blast radius the MOA becomes a little relaxed. |
| Posted by: Skidmark 2010-12-29 00:41 |
| #2 "MOTHERSHIP" CONCEPT + IMO indics or infers that in future, DIFFERENTIATED MAJOR WARSHIP CLASSES WILL HAD MERGED INTO ONE, which in turn could be deemed as the GRANDDADDY/GODZILLA OF ALL "SUPER-ARSENAL SHIP" DESIGNS. I suspect the above is the real, hush-hush reason for the UK'S "QUEEN ELIZABETH"-CLASS CVF HAVING TWO ISLANDS [Fwd, Aft], + WHY TO BUILD TWO CVFS BUT MOTHBALL ONE OF SAME. IOW, CVFS = notsomuch an [avant-garde]AIRCRAFT CARRIER AS AN "UN-IMPROVED" FUTURE ARSENAL SHIP = ALL PURPOSE/SYS MOTHERSHIP. The only thing it can't do is SUBMERGE like a Submarine ... ... ... OR DOES IT??? [DAS BOOT Movie here]. We should also the UK's present serious lack of cash, which lends to the dev of COST, MISSION-EFFECTIVE CONSOLIDATED DESIGNS. |
| Posted by: JosephMendiola 2010-12-29 00:36 |
| #1 Just how do you armor a ship against a 64MJ round? Or will everyone be building new versions of HMS Hood... |
| Posted by: Bill Griling5080 2010-12-29 00:29 |