Ship Design Systems

[Scott Martin]

Hi Whartung
You've strayed into the Acronym zone

C-PAW is a Charged Particle Accellerator Weapon
N-PAW is a Neutral Particle Accellerator Weapon
A-Paw is an Antimatter P.A.W.

Charged particle Accellerators are only usable in Atmosphere, since the charge dispersal will cause them to rapidly lose focus in a vaccum, N-PAWS neutralize the charge by adding oppisitely charged particles to the particle stream on firing. A-PAWS are a high tech (TL-15+) "Super Zap Gun one hit kills any ship" weapon.

My contention with using a particle accellerator as a delivery system is that if you are going to take the risk to store the stuff anyway, there are a *lot* of easier ways to deliver it, and IMO if you're going to mess with it, put it in "expendible" ships, since any hit on the containment system (or fluctuation in power levels) will write off yuour ship, whatever the size.

with a normal PAW you don't care a whole lot about the charged particles that you "throw out" when you strip your neutral gas 9or whatever0 to accellerate it. For an A-PAW you have to be a lot more careful...

Scott Martin

 

[aramis]

Scott: the idea of an APAW is that it is generating AM at firing time, not storing it. Just like the other PAW's.

 

[Ptah]

Originally posted by Scott Martin:

Charged particle Accellerators are only usable in Atmosphere, since the charge dispersal will cause them to rapidly lose focus in a vaccum, N-PAWS neutralize the charge by adding oppisitely charged particles to the particle stream on firing. A-PAWS are a high tech (TL-15+) "Super Zap Gun one hit kills any ship" weapon.

You learn something everyday. I thought these worked different, not that I doubt how they are described in the rules, its the physics.

So a C-PAW is basically an ion beam. Electrostatic repulsion is going to limit this beam in atmosphere as much as in vacuum. In fact I would imagine the beam loses are even more in atmosphere due to scattering collisions and they are even greater than that of an N-PAW as the collision cross-sections of ions with neutrals is far greater than that for neutrals with neutrals.

The N-PAW sounds like it could be a plasma(substantially equal numbers of positive and negative charges)unless charge transfer occurs to produce truley neutral particles. I'll assume it does.

So I imagined the C-PAW as a space weapon, the N-PAW a space or atmosphere weapon.

 

[GypsyComet]

IIRC, the C-PAWS is the atmospheric weapon of choice because preperatory ionization of the firing path is possible. This can't be done for an N-PAWS, but it requires the particle stream to be neutral over all. The two are really minor handwaves to allow for operation in all environments, as otherwise they function the same. They were also presented as the "color" necessary to introduce the A-PAWS in context (all were in the same article).

Yes, the A-PAWS is a kill-o-zap gun, which is why it was above normal Imperial TL in MT. Guidelines for using a A-PAWS to strip planetary atmosphere were even provided... It also can cause the traditional "visible beam" effect of it's ancestor, the Wave Motion Gun, as even the scattered atoms present in space will react to this beam. Quite a lightshow I suspect.

 

[TheEngineer]

Charge dispersal effects should be increasingly neglegtable at relativistic particle speeds. Thats one reason why real life accelarators like those in CERN work.
Scott, why would You think, that they would work only in athmo ?

The most significant part of primary interaction between a relativistic particle beam and athmo is purely kinetic nucleous-nucleous scattering. Charging can be neglegted at high energies. As momentum is preserved, secondary particles caused be scattering with relativistic particles just keep direction, thus forming a kind of beam core with a radius of just several meters.
Lower energy myons, electrons and radiation form a distribution around the center, where width is strongly related to primary particle energy (Thats from the CASCADE docu..).

Regarding those A-PAWS IMHO only using stored AM would give an advantage. Any "just-in-time" production would just represent another way of transfering energy provided in a time frame to a target.
So, pumping 1TJ in a CR into the kinetic energy of the particle round or pumping 1TJ into AM creation and kinetic energy just result into 1TJ as a gift for the target. Am I wrong here ?
Well, one advantage might be, that accelarator could be more compact, as kinetic energy is shifted into the material itself.

N-PAWS: Couldnt they be created by combining two particle beams of different charging ? Or create neutrons by controlled recombination of a proton, an electron and a neutrino ?
OTHO neutrons itself have a spin and in real life beams can be created the magnetic way.

 

[aramis]

TE: there was an article in JTAS claiming they wouldn't work in vacuum.

The operational theory is that the like charges within the beam will result in parallel particles repelling sideways and off-line of the target. It's reliant upon significant particle densities, and ignore the plasma membrane effects, which were only discovered recently. Plasma Membrane effects help explain the shape of solar prominences, as well, and why they don't just fade out at the leading edge.

At the densities involved, we're talking μg/m³. Just high enough to generate minor membrane effects, I think, and not high enough to function as a more conventional fluid, especially since we're talking about a beam originating at maybe a few cm² in cross-section, and potentially several dozen meters long.

Besides, the Kinetic forces are not the purpose of PAW's in real weapons uses; they are intended to generate secondary radiations, just like they do in the cyclotrons. Cause radiation damage to crew and kit. Most of the K.E. should be transformed into liberating molecules, and releasing EM Radiation on target.

In substances such as superdense, that could quite possibly trigger a cascade effect; this cascade effect magnifies the effect of radiation striking metals, as most metals in being split actually release a tiny fragment of excess energy (not enough to sustain reaction, however; if a sufficiently high-energy particle collision occurs, it should produce some cascade effects due to kinetic transfer).

Instigating a cascade with Antimatter is going to produce a very different type of radiation pulse, by localizing the initial pulse with an AM reaction; more energy in a shorter packet, thus over a smaller area of hull, and more Gamma and X-ray radiation.

The overall packet energy need not be higher to be more effective; just concentrated better by a shorter, tighter pulse.

 

[mike wightman]

Originally posted by Ptah:
I also like the idea of the missile being deadlier at short range so there should be concern if a squadron of enemy fighters penetrate the fleet's fighter screen.

The classic torpedo run idea - I like it too.

The combat system alteration being, missile defenses are very good at taking out incoming missiles (due to increased vulnerability to fire not necessarily increased susceptability), so missiles fired at short range have a much better chance to hit. This provides a role for the fighter/a more heavily armored missile delivery vehicle.

And also an increased role for anti-bomber interceptors and escorts.
What DMs do you actually use in High Guard for this?

I like escorts so much in my modified version of HG combat I've added an escort "box" to the force "box" with rules geared to supporting designs of escorts. Actually two designs, one anti-figther, one anti-missile.

Another good idea, could you give further explanation?

 

[mike wightman]

Originally posted by Scott Martin:
I'm more envisioning lots of "PT-boat" sized combatants supporting larger specialty-built ships.

A lot of people think that the PT-boat is a better model for what CT fighters are like - the image of aircraft in space is flawed.

Imagine a stealthed up version of a WWII E-boat with two Harpoon missile launchers in place of torpedos...

There are only two roles I can see for "Big Ships" in this type of environment:

1) Really nasty bristling with point defence monsters (obvious)
2) Invasion, Support, Transport or Merchant vessels

A lot like the designs which turn up building a TL12- fleet with High Guard. At these TLs the fighter wing can win a battle, at higher TLs smalller power plants, better armour, better computers, and improved nuclear dampers reduce the effectiveness of fighters.

If you are building one of the aformentioned monsters then you are playing a dangerous game: you can stop N missiles, but a N+1 you loose a lot of investment.

I can actually see the Imperium favoring "Big Ships" if only because they can afford to lose a big ship to every small ship their opponents can field and still come out (economically) ahead. Possible exceptions being the Solly's and Zho's, but if *they* can be convinced to build big ships too, then there's no problem maintaining a balance of power.

This assumes a somewhat cynical view that the "Major" powers are more interested in keeping the "minor" powers in line than actually expanding their borders against other major powers.

Scott Martin

I agree with you completely Scott.

 

[mike wightman]

I think that Aramis is right that at above Imperium TLs antimatter is produced at the time of firing.
IMHO and IMTU antimatter production is achieved by using magi-tech to change normal matter into antimatter - nuclear damper/meson screen blah blah handwave etc

I don't make it a ship killer though. It allows the APAW to be smaller - use the meson spinal sizes - but is much more expensive and requires even more energy than a meson gun.

It attacks as a PAW of equivalent factor, a successful hit causes a damage roll on each damage chart, normal extra critical and spinal effects apply except it takes two factors of armour to reduce the spinal extra damage, and each hit (not each damage roll) reduces the target armour value by 1.

 

[Scott Martin]

Engineer:
The reason that dispersal isn't a problem with CERN etc is that the beam path is both inside a focusing ring AND the beam path is really short (compared to space combat distances: pretty much anything on a planetary scale is "short range" for a system with a performance envelope in the light second range...)
C-PAWS use a laser to ionize a beam path through an atmosphere and the particle beam follows the (lower resistance) ionized column of air. They are doing similar stuff to "direct" lightning strikes near airports (I believe this was published in Sci. Am. in the last year)

Aramis:
The "High Guard" specs for the A-PAWS were *massive* systems. Yes, they generated the antimatter on site, but if you can generate antimatter, and it takes a huge generator then it doesn't make a lot of sense to put that (large expensive) generator in harms way. I believe that the published specs on these were more than an order of magnitude bigger (and more power hungry) than the type-T Meson spinal mounts, so why not mount 10 Meson mounts instead? This kills Sigg's post, since the A-PAWS were *massively* larger than a PAW of the same size (several orders of magnitude is my recollection: I believe that the ones at T-15 started at factor-A)

As for the radiation cascade effect of a PAW, you'll get a cascade hitting a steel hull, let alone a superdense or one, but Traveller has never modeled this well. In the Real World(tm) the crew of a ship would be fairly nicely cooked by a PAW that didn't penetrate the hull. ProjectRho goes into this, but telling your players to roll up new characters every time their ship takes a PAW hit would be pretty tiresome.

(handwave)
If you have the tech to build a free electron laser and Nuclear Dampers, you can probably (trivially) protect your crew against radiation cascades
(/handwave)
[edit] add "compact fusion reactors" to the above list...

Scott Martin

 

[aramis]

Scott:
agreed, it's not modelled well.

In a CT/HG setting, the APAW should generate extra damage as radiation, not pen/surface.

Not having the article to hand, can't comment on specifics of size. I did however, go looking in MT, where they conspicuously DON'T appear.

Further, given the HG vagueness, there is little to suggest light-second ranges to me.

 

[mike wightman]

The light second ranges come from the Mayday/High Guard crossover rules.
In Mayday one hex is one light second , and High Guard weapons have a short range of five hexes

And, even in CT, weapons had ranges measurable in light seconds.

 

[mike wightman]

Scott,

I don't agree with the JTAS article about APAWs - hence the IMTU version

But then, the JTAS article isn't canon anyway

 

[Scott Martin]

Hey Sigg (and Aramis)

I now mostly use TNE (FF&S) for starship design / combat, since it's the closest to real physics that is currently out there that doesn't have "munchkin" design. Starship weapons (especially big PAW's) can have uattenuated ranges in the 6+ light second range. CT (book 2) had sensor and combat ranges up to 2 LS (and mods for laser fire at 1.6 LS or some such: sorry my LBBs have been in storage for a while)

Agreed that High Guard wasn't good at modeling ranges (and had space-based plasma weapons... my favorite turret weapon until I got "physics", which is like religion but requires more math) but it was a nice fast system for design and combat, and was my favorite for a lot of years.

Wrenching this thread back towards the original topic...

I still think that the best "combat" system (movement wise) for CT was the book 2 vector based system. Mayday tried to make this easy (and hex-based) which pretty much killed the point of vector-based movement. HG gave a nice sense of "epic" confrontations between capital ships, TNE made the Kininur and Close Escort scary again.

Try Brilliant Lances with Vector based movement, you may be surprised at how well it works. Missiles are a bit tricky, but work as long as you "lead" your target. I may need to put together some software to automatically generate the missile vectors, but you can usually "eyeball" them close enough, especially if you are using HEPLAR missiles instead of the (anemic) "stock" missiles.

This works best on a large playing surface with grease pencils, so that you can draw out the ships projected vectors for a couple of turns. I'll try to post my variant rules if there is any interest (may take a while to find and translate though)

Looks like Traveller wants to keep with the "Big Ship" universe (given the 1248 and T5 stuff I have looked at lately) so a "redesign" of FF&S or equavalent may be needed. FF&S scales well over aboput 5 orders of magnitude (1 cubic meter missiles to 10 Ktons / 140,000 cubic meters transports) but it doesn't handle capships well, since they tend to they run out of surface area (especially in FF&S-2 where T-12 fusion plants require an INSANE amount of area per MW)

I'll run the math and tell give max power / hull size at tech 11-14 (and max thrust/hull size, assuming all power goes to thrust) I may be wrong, but my eyeball "ballpark" estimates put a pretty low ceiling on the FF&S-2 cap ships because of "radiator area" for fusion plants.

Scott Martin

 

[Scott Martin]

A thought for Aramis:

for HG PAW's double (or triple) the A-PAW factor for the purpose of critical hits. at triple, any spinal mount A-PAW will inflict crits on anything, at double anything smaller than a heavy cruiser is taking crits.

Scott Martin

 

[aramis]

Scott:
I don't use HG, not even the MT variant.

I instead use the personal/vehicular combat rules for all scales, grafting on a mayday derived movement system.

Now, your math should find that an AHL should only be able to sustain about 2G under FF&S, IIRC. Someone on the TML did the math back in about 96.

The BigShip universe fails with FF&S. Known quantity.

 

[mike wightman]

Scott,
as soon as Battle Rider came out I switched to the Mayday like vector movement of that game, away from the Brilliant Lances method because the latter, IMHO, was too difficult for casual participants to get their heads around.

Have you ever seen the grand daddy of them all (well, the GDW ones anyway ), Triplanetary?

 

[Scott Martin]

Actually I did the math and (surprisingly to me) reactors were not an issue unless you were using a spherical hull and tech/9 reactors (max was just under 6G for a 1 MT displacement hull.

That said, spherical hulls can only do 6G (with HEPLAR) up to about a 15 Kton hull, and a "dispersed" hull will stop being able to pull 6G at just under 1 MT. Thruster plates use significantly less area, and probably aren't restricted to being on the aft quarter of the hull

This means that FF&S is (theoretically) good all the way up to megaton displacement monsters, although I haven't even tried to build one of these behemoths. Square root damage will give issues in the tens to hundreds of kiloton range, since hulls can be thick enough to stop ANY "standard" weapon other than lasers. (I'll have to do the math on the size of ship that can have a hull too thick for the biggest PAW it can carry to penetrate)

I haven't played triplanetary, but a look at the BR rules made me glad that I had picked it up used... I generally prefer to model combat (not in game) using a fairly detailed combat system, and then when I am actually running an RPG, instead of getting out the counters, dice etc. I have a good idea what the vessels can do, so I "wing it". Keeps (PC) ship engagements to 30 minutes or so, unless there are wargamers playing (then they take a session). Results tend to only be different based on which systems get KO'd except for hit distribution which (as a GM) you can simply apply to the systems that were *supposed* to get hit.

Scott Martin

 

[GypsyComet]

It's also well known that TNE combat among the cap ships is all about scrubbing external features to attain a mission kill, unless someone brought the meson spinals. Enough surface hits will eventually render even a capital ship blind, weaponless, and unable to manuever. With enough radiator surfaces damaged, even the PP becomes a problem to run.

This is why, even without the monster missiles of TNE, fighters become useful in TNE again. Anything that scrubs external systems (sensors, airlocks/hatches, weapon ports, radiators, drives) is useful. Note that TNE was developed with the prior uselessness of the fighter in mind. If the fighters can scrub enough sensors off the opposing capital ships, they'll never see the next wave...

 

[Scott Martin]

IMO Big ships in the TNE universe are still more "target" than utility. TNE small craft combatants were also problematic. IMO this is good, because that is how I envision a space combat environment: a balance between "big enough to do the job" and "small enough to be cost effective".

And now on to the small craft bashing...

The only "Fighter" I have seen for TNE (The T15 "Rampart") looked like it "bent" more rules than it should have. A concrete example would be the min crew (by TNE) of at least 4: Pilot, sensor ops, weapons ops and an engineer. You could wave away the engineer, but if a fighter can combine Pilot, Sensor ops and gunner into one, why can't other ships?

The Modular Cutter "Laser Mount" used an air-breathing power plant to power the laser. Did the designers pack all of the extra mass and volume for the oxy as well? (multiply fuel mass and volume by about 3, if you need to bring the Oxy as well...)

This sort of Kyboshed small craft for me, and trying to pack a useful set of weapons, the minumum crew for them and any maneuver / endurance is well-nigh impossible until Tech 13, and useful small craft really need a high density power plant (TL 15) A possible option for these would be as a missile bus, but then you either need:
1) Fully Independent "Fire and forget" missiles
or
2) A lot of crew to direct ("aim") them

for the first point I'm still peeved about the *total* lack of rules for FIM's, despite the fact that the (published) fighter was supposed to carry them. In addition to the lack of rules to support them there were no FIM's provided in the game!

Small craft seem to make sense at lower tech levels, since fire control is such that you need to get (relatively) closer to be effective, but this is more than offset by the poor power/weight ratios of lower tech power plants.

Low Tech fighters won't be fast enough to run, have low fuel reserves for evasion, are really expensive ton-for-ton and still have the damage capacity of an eggshell. Not a winning combination in my book.

Another alternative is to assume that your small craft are expendible, and throw lots of small, cheap, missile armed fighters at something. As long as some of the fighters survive they can take control of *any* of the launched missiles at knife range, but this is an excellent way to go through flight crews, and probably isn't very good for morale

Scott Martin

P.S. Cap ships do have the alternative of *launching* extra antennae if their sensors have been scraped off: I'll post another thread on independent synthetic arrays (and rules for them)