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 Question about mass drivers?
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| Aldirin |
Posted on 04-11-2007 06:15
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 Posts: 8 Joined: November 04 2007 |
Is there any reason mass drivers/railguns are so marginalized in PDS? Plasma DEWs seem to have taken their role over. Given PDS' reputation towards realism (or at least authenticity) shouldn't it be the other way around? Plasma as a weapon is completely unviable. Physics work completely against it. No matter how much energy is behind it, it'd simply spread out. You'd need something several hundred GPAs to hold it together, and at that point why not just impact it with your incredibly hard substance? Or use the same technology as a forcefield. A railgun? Well honestly we aren't sure too much about the physics of objects that go over 1.5 km/s. We can calculate the amount of energy it'll impact with, but how an object reacts is a different issue. An object going sufficiently fast will impact with a lot of kinetic energy, on the scale of a nuclear weapon at sufficient masses or velocities (kinda high, a hundred km/s or so). The United States Navy is interested in railguns for several reasons, not the least that you can do the damage of a Tomahawk at a fraction of the cost. Just as a conservative example, a 90 kg object moving at a constant velocity of 5 km/s is going to impact with over a gigajoule of energy! It does require 5 gigawatts of power to do so, but the damage is about the same as tonnage in TNT (it is impacting with the same energy that 90 tons of TNT exploding would generate). Not quite weapons grade, but certainly not fun. Hopefully this post isn't too harsh, I enjoy PDS a lot but I've always wondered why railguns never seem to accomplish as much as my missiles or DEWs. Given similar energy levels from the main reactor, is there any reason why railguns wouldn't impact with the energy of a tactical nuke? |
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| Tristan |
Posted on 04-11-2007 08:07
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Posts: 304 Joined: June 28 2006 |
There are railguns in PDS? If you're just referring to the AC275 and AC220's in PDS11, they're not really railguns. They're projectiles with timed explosives that detonate when within the closest estimated radius to the target. And they don't move that fast. If you're saying there should be railguns in PDS, I wouldn't disagree. It'd be a nice implementation. It'd be easy to counter their devastating power with a very long reload rate. Or perhaps decreased accuracy. Edited by Tristan on 04-11-2007 08:07 |
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| Aldirin |
Posted on 04-11-2007 17:26
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Posts: 8 Joined: November 04 2007 |
That's a good point, I forgot the large caliber cannons are all autocannons (I assume?) instead of railguns in the current version of PDS. So I guess extend to the question to why not railguns instead of plasma cannons and the autocannons? |
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| Ironwatsas |
Posted on 04-11-2007 18:20
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 Posts: 856 Joined: October 21 2005 |
Railguns are actually commonplace among PDS' various devices of doom, and for the most part do what Aldirin stated. The thing with Railguns is their power consumption is significantly higher then a chemical based projectile weapon (but far lower then a Directed Energy Weapon). Several Hiigaran ships use Railguns as their primary batteries, predominantly the Arbiter series of 325mm and 350mm (If I remember my numbers correctly) railguns mounted on the Arbiter Lineship, Prince of Hiigara battlecruiser, and many other ships. Railguns are great if you need to throw something with a lot of kinetic energy at something in not a lot of time. Problem is, the trajectories can become outdated yery quickly, as both the target and firing ships are likely to be moving all over the place. That is why Railguns are largely secondary to Particle Weapons, Guided Weapons, and Proximity Fused Cannon Shells. Railguns could fire proximity shells from a Sabot with no modification, but any electronics would likely be fried from the electromagnets, so you'd need a mechanical fuse or something, which is less reliable. A solution to the Magnetic field is some kind of Mag-Insulated Sabot which would protect the electronics of whatever it's launching. We largely use Railguns for bombardment of large targets, and with insulated Sabots, they can fire proximity detonating shells and missiles, but are generally best used when bombardings something large and immobile like a space station or planetary structure. Railgun weapons in planetary combat is another story... |
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| Aldirin |
Posted on 04-11-2007 18:54
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Posts: 8 Joined: November 04 2007 |
Sorry being such a pest about this. I guess my point is large ships are moving at what, approximately 100m/s? With frigates and fighters moving much faster but stilll not a km/s. And engaging around a few km in distance. A railgun, depending on how much energy you can give it and the distance of the rails can easily hit in less than a second. It's not going to nearly c like a particle beam, but it will be around your target certainly. I'd like to imagine Fire Control System could at least figure out the delta-v of movement for an enemy space craft and get near it. The sheer velocity could get you close to the target even with movement (I was thinking maybe lower mass but at least 15 km/s slugs to keep power requirements down?). I'll apologize for being so silly about this. Railguns are something of a hobby, I just think most science-fiction tends to get it wrong. |
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| Ironwatsas |
Posted on 04-11-2007 19:25
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Posts: 856 Joined: October 21 2005 |
Well, we're not most science fiction  Functionally, Railguns work as they do in real life. Implementation them is a bit diffrent given that this is Science Fiction. We've had to improvise a bit. But Railguns are much better in planetary combat where velocities are more reasonable. Imagine a Railgun or two mounted on a train used as an anti-orbital cannon powered by a secondary locomotive's prime mover (something I'm going to replicate in my train layout). At any rate, your argument is valid. Tel is the one here who's the expert on weapon implementation and individual devices' characteristics and whatnot (he coded most of it). |
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| Komo val |
Posted on 04-11-2007 19:40
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Posts: 392 Joined: September 27 2006 |
Aldinir, yes PDS strives for realism, however the HW2 engine prevents more realistic battles (as tried in the experimental versions).Thus it would be rather strange (although very good looking with the proper effect) to have near-light speed projectiles in such a ''small'' space. Now shifting to ''realistic'' In reality space combat would take place over massive distances, thus giving you ample reaction time, even a small movement would be more than enough to escape a projectile. Furthermore any chemical explosives or guiding systems mounted on railgun\gauss cannon projectiles would be subjugated to extreme G-forces which would either call for a removal of guiding systems or a massive improvement in said technologies. One way to counter the lack of guiding systems is to make your projectile ''stealthy'' radar, EM absorbent, thus reducing the reaction time. Even with this, the amount of energy to propel a significantly large-mass object would be significant. Even the space shuttle has effective anti-projectile armor (meteor) basically the outer layer and the inner layer are separated by a gap. thus the energy adsorbed by the outer layer of the armor is more or less equal to the energy absorbed by the projectile which desintagrates and makes it easy for the main armor to absorb the loosely spread particles. As said before propeling a projectile with enough mass, that is density, to stay intact enough to carry significant amount of energy to penetrate the inner armor. Plasma weapon containment could act similarly to the magnetic field on earth. Having a rotating solid core, metallic of course sourounded by liquid would make a mag field, however if that would be enough I don't know. We maniged to create high-temperature plasma (8x the temperature at the center of the sun), now we just need a containment field, which I have no doubt that this will happen in the next 100 years or so. Railguns are your hobby you say. Well suit yourself I prefer gauss cannons. 
Edited by Komo val on 04-11-2007 19:44 |
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| Tristan |
Posted on 04-11-2007 23:05
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Posts: 304 Joined: June 28 2006 |
I prefer missiles myself. And rockets. And torpedoes. And, ... *foams from mouth.* |
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| Aldirin |
Posted on 05-11-2007 00:34
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Posts: 8 Joined: November 04 2007 |
Komo val: I appreciate the lack of light second combat. That'd be annoying to deal with, and impossible at HW2 scales. I actually take your point on whipple shields. We actually have plasma containment in tokamak fusion reactors. it's called plasma bottling. That doesn't really change how plasma isn't a super great weapon, think of it as a superheated steam launcher, after the containment splits the plasma just radiates everywhere randomly. I was reading through the Homeworld 1 manual since it has a nice technological overview. Apparently even the small massdrivers on fighters go 10 km/s, with larger weapons certainly being close with a greater mass (hey the heavy weapons turret is half the length of a frigate!). The plasma bombs are basically described as being magnetically bottled plasma from the reactors, which is interesting but still subject to the same problems as above. Missiles are described as using magnetically bottled plasma from the fusion reactors as their reactant mass, method of damage isn't mentioned. I guess given the materials science in the Homeworld verse I would expect some kind of nano-scale material that is sufficiently hard and dense while being conductive to use on the rails as well as the slugs. Railguns would of course not be as accurate as particle beams, .99c is fairly fast, and changing railguns to relativistic kill weapons seem out of reach given Homeworld's slight hard sci-fi bent. Still all your replies have been very civil, I almost feel like I'm being too harsh on Tel and the team for mentioning this, it's just something that came to me last night while playing HW2. |
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| Komo val |
Posted on 05-11-2007 14:59
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Posts: 392 Joined: September 27 2006 |
No, I very much like these discussions If we find a way to project magnetic containment field, plasma weapons would be very lethal in planetary combat at least. Imagine a projectile as hot as the sun impact a tank. In space, given the same obstacle has been surpassed, plasma could be used as an anti-stikecraft weapon (since you would need large amounts of heat absorbing material) or for saturation fire against capital ships to ''soften'' their armor. Containment field failure is very plausible. That why plasma weapons where given a shorter range in v11. Again this opens the space for many interesting countermeasures such as magnetic projectiles that use their strong magnetic fields to destabilize the containment of the projectile. One more likely use is in a combination with a real projectile, which would provide the containment field and penetrating power, while the plasma is a much more destructive substitute for explosives. ---Magnetic acceleration and mass---- Accelerating a object with substantial mas to that fraction of the speed of light is near to impossible. The particle accelerator at fermilab, that is it's magnets, produce 4.2T (teslas-the unit to measure the strength of a magnetic field) and accelerate a proton to more or less that fraction of c. Now a proton weighs approximately 1.6x10 to the -27th kg thats more or less 3.8x10 to the -27th pounds, for those accustomed to the imperial system. Thats: 0.0000000000000000000000000016 kg, a person ways about 80 The strongest artificial pulsating non-destructive magnetic field is about 100T, using explosives 100x10 to the third T. The maximal THEORETICAL magnetic field of an entire neutron star is ''only'' 10 to the 13th T. Thus to accelerate a object of 1kg to that fraction of the speed of light would take a magnetic field of 10 to the 27th T. More than two times as strong as the strongest theoretical magnetic field of an entire neutron star. ---Sorry for the physics----- But even a gram of matter accelerated to 0.5c would have enormous kinetic energy. EDIT: Know that i think of it we should have more conversations comparing real-life theory and Hw\Pds tech. Edited by Komo val on 05-11-2007 15:05 |
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| Knare |
Posted on 06-11-2007 04:38
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Posts: 75 Joined: December 31 2006 |
Quote Komo val wrote:The strongest artificial pulsating non-destructive magnetic field is about 100T, using explosives 100x10 to the third T. The maximal THEORETICAL magnetic field of an entire neutron star is ''only'' 10 to the 13th T. Thus to accelerate a object of 1kg to that fraction of the speed of light would take a magnetic field of 10 to the 27th T. More than two times as strong as the strongest theoretical magnetic field of an entire neutron star. Sorry to nit pick but 10^27 is a whole lot more than double 10^13 (lol exponents, I hate them too). More like 10^14 times stronger. Also plasma weapons are useless inside an atmosphere. The blob would face forces that would tear it to pieces before it could leave the barrel (Halo and X-com?). Also the superheated material would attract electrons like crazy turning back into a gas. However, space is more ideal because there is so much less junk around to get in the way. Plasma is ideal is certain situations because it could be devastating versus large hulls which are easy targets. Don't get me wrong, I love BIG GUNS. Nothing like huge ballistics to lay waste to your opponents, but energy is so much easier. It's easy to come by (most larger ships use anti-matter right?) and cheaper. Energy has so many less restrictions. |
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| Ironwatsas |
Posted on 06-11-2007 06:13
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Posts: 856 Joined: October 21 2005 |
Quote most larger ships use anti-matter right? :topic: Not nessiscarily. Antimatter is extremely difficult to synthisize, difficult to store, and even more dangerous then Nuclear Fusion or Fission. As a power system, it is either beyond the reach of or not practical enough for most of the contemporary races. The Taiidan do use antimatter catalysed Nuclear warheads and the T-MAT and Kassi have antimatter reactors on some of their larger ships, but only those where another power genoration method is unfeasable. :topic: The problem with plasma based weapons is that a bolt of plasma, even in space, will cool within less then a second. Aside from specialised close range saturation or heavy duty weapon systems, Directed plasma weapons would be less effective then Autocannons or Electron Particle Weapons. Anoter thing is the fact that many starships have some kind of ceramic heat ablative plating (akin to the heat shield on the space shuttle) for operation in high temprature environments (nebulae, vicinity or stars, re entry, etc) as a basic construction measure. This would negate many of the heating effects of a Plasma or Laser weapon. Plasma based weapons have the advantage of some degree of kinetic energy and a magnetic charge. Still, a hybrid Projective-Plasma shell would probably solve the problem of superconductive plating, the mass of the solid componant would break through the ceramics, and the heating would melt the hull armor. Another idea would be firing some stable element at a target that works through rapid corrosion as opposed to heating (the principal behind the common Kassi S-MAG weapon). Effectively, a corrosive substance that can withstand vaccum and is fired either in a shell that can contain it, or with a magnetic or gravity field at a target, possibly splattering just prior to impact to create a larger area of effect. Thoughts? |
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| acelynham |
Posted on 06-11-2007 08:43
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 Posts: 183 Joined: September 23 2007 |
it's at times like this that i wished id listened harder in physics... though i am loving this thread nonetheless! |
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| Makaze |
Posted on 06-11-2007 16:52
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 Posts: 53 Joined: May 29 2006 |
Thoughts... 1) Most of the plasma weapons in stock HW2 are in fact plasma driven laser lances, as is the case in the Vagyr beam fighters. 2) Wouldn't a proper magnetic bottle isolate the plasma from vac entirely, preventing its heat energy from bleeding away? Isn't that the point of bottling it, as opposed to just forming the packet itself and blasting it across the stars? In such a situation, you'd have a small interior unit that projected the containment field itself. This field would be injected with superheated drive plasma from the reactor of the ship, readied for launch and fired at a target. It would be similar to a Star Trek photon torpedo. Now. The plasma is not a gas upon impact, assuming containment held. Given a reliable power source of some kind on the bottle unit, the plasma would then have inertia equal to the unit's - like people inside a car are travelling at the same speed as the car, and more inertia depending on how far the plasma packet had to accelerate - and at the speeds the weapon would have to be launched to be effective, the plasma shouldn't have time to dissapate before impacting its target, in perhaps a slightly larger and irregular area than the sphere or oblong containment field that it travelled in. 3) In the above scenario, the heat ablative armor would have to be strong enough to survive the interior of a sun for a fraction of a second (a material that we as humans have no inkling of without the help of an energy field), and the extremely rapid cooling of this armor would likely crack it, especially if it were a ceramic - it would not last a second impact. 4) Why would you need to accelerate anything to those speeds to be weapons-grade? .5c, for example, would have exponentially lower energy requirements and still be too fast for most vessels to dodge, unless they were strikecraft or were comparatively very far away. Objects at this speed move 149896 km/sec. Also, objects in a gravity-devoid vacuum keep their acceleration rather than slowing down, so you'd only need to provide a fraction of that in acceleration, as opposing to muzzle velocity. 4) Acid based weapons? Fun! Your only difficulty would be finding out what exactly your enemy constructs his starships out of, compose a chemical to break it down, and fire away. As far as vaccuum goes, you'd simply have to add a lot of antifreeze...? I don't know anything about containing liquids in vac, except that they do flash-freeze. Maybe use some sort of limpet mine that attaches to an enemy hull, creates a pressure seal, and then shoots a jet of corrosive acid into its target? "...We sank a truck!" - Commander Sherman, Operation Petticoat
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| TelQuessir |
Posted on 06-11-2007 17:13
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 Posts: 2598 Joined: August 30 2005 |
Quote Maybe use some sort of limpet mine that attaches to an enemy hull, creates a pressure seal, and then shoots a jet of corrosive acid into its target? Give me an explosive charge anyday. |
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| Aldirin |
Posted on 06-11-2007 18:20
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Posts: 8 Joined: November 04 2007 |
I'm going to completely ignore relativistic weapons except the particle cannons. Given enough energy/large enough capicators, it would be possible, but I don't think having mile long coilguns or railguns with gigantic terawatt or up ranges sounds appealing in the HW-verse. I have tested out railgun velocities. Going 5500 m/s is more than enough to reach out and touch someone, rather than the default leisurely pace of the AC's (1.5 km/s!). I also replaced the BBX's nuclear torpedoes with faster, larger railguns. I assumed it has a larger or more fusion reactors than BC's. As for why plasma weapons just don't work, I'll turn to Mike Wong. A much smart guy than myself, but a lot more abrasive too. http://stardestroyer.net/Empire/Essay...apons.html On a different note, (I've managed to derail my own thread, how nice) are the ion cannons still a directed stream of protons in PDS or have they evolved into a neutral particle cannon? I'd rather have lances described as powerful lasers than plasma, overlooking a plasma-esque particle beam, which could actually be how plasma cannons operate (but they have such a low velocity I have a hard time believing that). |
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| Ironwatsas |
Posted on 06-11-2007 19:24
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Posts: 856 Joined: October 21 2005 |
Quote are the ion cannons still a directed stream of protons in PDS or have they evolved into a neutral particle cannon? I think it depends on the individual weapon and manufacturer (moreover, the technonogy employed by said manufacturer). I'm no expert on the subject, but from what I can gather most Ion cannons use Ionised light elements (hydrogen, helium, lithium, etc) or the Ions fron said elements, focused and energised along a series of superconducting coils, and accellerated with either a laser or magnetic accellerator (or both) toward a target. I'm no expert on the physics and cannot classify it as a proton stream or a neutral particle, so someone with more knowlage on the subject should enlighten us. |
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| Sun Tzu |
Posted on 06-11-2007 19:29
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 Posts: 528 Joined: September 08 2005 |
Quote Going 5500 m/s is more than enough to reach out and touch someone, rather than the default leisurely pace of the AC's (1.5 km/s!). Edited by Sun Tzu on 06-11-2007 19:30 |
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| Knare |
Posted on 07-11-2007 01:24
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Posts: 75 Joined: December 31 2006 |
Quote Ironwatsas wrote:The problem with plasma based weapons is that a bolt of plasma, even in space, will cool within less then a second. Aside from specialised close range saturation or heavy duty weapon systems, Directed plasma weapons would be less effective then Autocannons or Electron Particle Weapons. Anoter thing is the fact that many starships have some kind of ceramic heat ablative plating (akin to the heat shield on the space shuttle) for operation in high temprature environments (nebulae, vicinity or stars, re entry, etc) as a basic construction measure. This would negate many of the heating effects of a Plasma or Laser weapon. Plasma based weapons have the advantage of some degree of kinetic energy and a magnetic charge. I disagree with part one but agree with part two, I forgot to think of counter-measures to stop the plasma. But as an example, think of a conoral mass emission. They can travel for days without cooling (probably cool significantly but not enough to lose consistency). Quote Ironwatsas wrote:I'm no expert on the physics and cannot classify it as a proton stream or a neutral particle, so someone with more knowlage on the subject should enlighten us. I never thought of them as particles beams. I'm no expert, but I always thought they were photons; just to me, they feel like high-output lasers or masers. Thats what I think when I see them discharge. However, particle beams could achieve the same role and results. Or perhaps, Hiigarans use photonic weapons while the Vaygr forces use other particle beams or vice versa. |
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| acelynham |
Posted on 07-11-2007 20:37
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Posts: 183 Joined: September 23 2007 |
dude, bear in mind a coronal mass emission is so fricking huge that it disrupts power lines on earth as it passes (true, btw- i read national geographic and have the poster on my wall :-P)... the size we would be dealing with when the largest ship able to field a weapon is only several hundred metres long would be considerably considerably- perhaps even ridiculously (if you'll excuse the hyperbole)- smaller than a CME loving this discussion though. sorry, just had to comment! |
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