Fighters in YTU

[travlar]

With just LBB2, fighters can be used for massed firepower. With minor tweaking of the rules, fighters can be allowed to go faster than 6Gs. In fact, some rulesets might not explicitly state that 6Gs is maximum acceleration. Also, consider the size of the lasers targeting the fighter, random zig-zaging will drop the chance of hitting with a delay of one second. With a small ship, it could, in one second (I think), no longer be at all where you expected it to be.

In Traveller I think that for fighters to work, they need strong weapons that can be fitted on them that can penatrate the bigger ships armor. If they have that, then they are good for getting more shots off faster then the big ships.

In most sci-fi, the fighters fly up close (allowing them to hit the weak points), and the shots move slowly enough that they can dodge.

 

[whartung]

You must realize that with aircraft, you have the wings and other surfaces to change craft direction. This gives them the nimbleness and high rates of direction change.

In a vacuum you don't have those lift surfaces and must rely on the M drive to make vector changes.

The trick is that you must maneuver the M-drive to point opposite the change desired. If you want to go left, you need to point the M drive right.

But lets take the simplest case. Let's take a fighter with a 6G drive. Let's for argument sake say he's coasting on 2 G-Turns (1 G-Hr) of acceleration. Which mean 1G acceleration for 1 Hr.

We'll also use 10m/s^2 for our acceleration to make math easy.

So, v = at, or 10m/s^2 * 3600, or 36000m/s velocity.

If the fighter is simply coasting, then a firing ship would "know" exactly what the fighters future position will be, base on its velocity vector.

Now, if the drive kicks in at 6G for 1 sec, that's a new velocity of 36060m/s, but only a change in predicted position of .5at^2, .5*60*1^2, so 30m.

Now consider two things.

One, any ship with a 6G drive can do that, not simply a fighter.

Any ship larger than 30m in length is "too big" to get out of its own way. If a targeting computer says "ship will be at x + 36000m" at time T, and the ship is actually at x + 36030m, you'll note on a large ship there's still some of the ship at the 36000m mark, and thus the weapon hits.

Also note that this is only if the target vessel is flying on a vector parallel to the firing ship, any other direction gives proportionally less benefit depending on what the angle of attack (whether closing or leaving). If the target is closing perfectly with the firing ship (perpendicular course), then there's effectively no change in predicted position (at least for LOS weapons, Mesons would be affected as they're designed to decay at a specific point in space/time, but Lasers and PAW wouldn't be affected).

Also, the closer you get to the firing ship, the lower the turnaround time for light to travel from target to firing ship, and any benefits of random drives bursts eventually approach zero because turn around time approaches zero. At 1 sec distance, a ship larger than 30m is too big, but at .5sec distance, that number is now 15m.

Finally this is assuming simple acceleration or deceleration. For any DIRECTIONAL vector changes (rather than simply vector length changes), you must rotate the main drive in order to affect change. And that transition will most likely take time vs micro bursts of acceleration without ship pitch change. During those transitions, your evasion is effectively zero as you vector isn't changing.

This also assumes that there is no build up of thrust from 0 to 6G, and that it's instantaneous.

Now, you can certainly throw a ship in to an end over end spin and start firing the drive randomly, that's the perfect evasive maneuver and most likely the most effective one, particularly for small ships, but beyond being a target, a ship in that state is combat ineffective as it can't fire back. But it's a difficult target TO hit, particularly at range.

So, in summary, IMHO, against light speed weapons, agility is a factor of drive output (max G rating) and ship size (ship needs to be able to get out of its way), and a factor of range to target. The farther away, the more effective this agility is.

 

[Sifu Blackirish]

At the surface, it seems pretty clear--except that torpedo boats were originally intended to take out at least destroyers

I think you might have it backwards. IIRC destroyers were originally called 'torpedo boat destroyers'--tougher and faster than their intended target.

IMTU all capital ships and most fighters carry nuclear missiles--a great ship killer, especially in mass attacks.

Certainly agree with the agility discussion. Computers already aim and fire much faster than humans (the Gatling-gun anti missile system comes to mind), so size might be your only real defense, unless you kill the other ship first.

 

[BetterThanLife]

Originally posted by Dominion Loyalty Officer:
</font><blockquote>quote:</font><hr /> At the surface, it seems pretty clear--except that torpedo boats were originally intended to take out at least destroyers

I think you might have it backwards. IIRC destroyers were originally called 'torpedo boat destroyers'--tougher and faster than their intended target.

IMTU all capital ships and most fighters carry nuclear missiles--a great ship killer, especially in mass attacks.

Certainly agree with the agility discussion. Computers already aim and fire much faster than humans (the Gatling-gun anti missile system comes to mind), so size might be your only real defense, unless you kill the other ship first. </font>[/QUOTE]There is also armor and redundant systems, which the bigger ship will have and the smaller ship will not. Your bigger ships won't just be more efficient, they can also soak up more damage.

Nukes are only effective if the target doesn't have Nuclear Dampers, and/or multiple point defense lasers.

 

[rhoneycutt]

imtu, fighters are good because of how I rate acceleration < by mass and not volume >, thus fighters with small mass can out do a big ship with heavy armor most of the time.

for a turn, I have ships allocate thrust for aiming, manuver and evasion. Attitude thrusters give max g's for aiming fixed weapons/spinal mounts
main thrusters give max g's for opening/closing range
avg of the two give max available for evasion.

a hi-g ship that can't change attitude is just as helpless as a ship that can swing about really quick without being able to 'go fast' (a ball spinning in place)

and by using reaction drives, each g-turn is precious, so you really have to choose when you burn. Running low on fuel when a salvo of missles inbound sucks.

 

[The Oz]

IMTU (a hybrid of LBB2 and HG, at least where ship design and combat goes) fighters are an annoyance to real warships, not a menace. It takes huge numbers (hundreds) of fighters to threaten a battleship because of the BB's multi-layered defenses and innate toughness. And fighter losses will be heavy.

That said, fighters are useful for lots of things: scouting, screenings, patrols, anti-piracy work, convoy escort, and harassing PCs in their little merchant or scout ships.

 

[epicenter00]

IMTU, fighters have a vital role in naval combat, though they're not totally decisive. Big starships, with their CIWS and Nuclear Dampers are indeed pretty much immune to fighter attacks in a similar way to the fact that modern tanks are immune to guys armed with rifles.

However, big starships are not immune to the attacks of gunships. You can think of these as something akin to a bomber armed with a long-range anti-ship missile (like some of those ancient Soviet-era Bears armed with those huge "Kelt" AS missiles), a PT boat, or the guy armed with a TOW or a Milan missile against armor.

Essentially, I detailed out the rather "magical" nature of Nuclear Damper boxes so that they're not fullproof. It's possible to create a field that negates a Damper field - temporarily by using a resonance principle that will collapse the Damper field, but only temporarily. The equipment is heavy - too heavy and power hungry to stick on a snub fighter. The Nuclear Damper units on board large ships can "burn through" counter-field the smaller units on board these gunships pretty quickly. However, a skilled operator of a damper negation box can time when he turns on his negator and adjust the fields to eke out a few more seconds and so it's a full-time job on the attack run.

The gunships carry 2-3 heavy anti starship missiles, so aren't very manuverable (no magic grav plates in my world - people are using thrusters which require fuel). So these ships typically have a pilot, a gunner/defense officer (who operates the laser/sandcaster turret), a missile guidance officer, and the damper-negation field / ECM operator. These ships are reasonably cheap (cheaper than a big ship), somewhat stealthy, and can attack en masse. They're utterly vulernable to big ship guns, but in large numbers or during fleet actions when the big ships have other big ships to worry about, they can flank and overwhelm even BBs.

That's where the fighters come in. Fighters are used to kill the gunships - like tanks have to have accompanying infantry to keep anti-armor teams away. Fighter weapons can't hurt the big, well-armored battleships, but they can certainly hurt the gunships. In turn, the gunships can kill battleships, but are vulernable to fighters. So the gunship flotillas have their own fighters guarding them, which fulfills my need for cinematic dogfights/furballs as well as providing a glamorous role for (former) fighter pilots as player characters.

---

An aside, on the anti-fighter rants:

I've always thought that Traveller had an innate bias towards large ships. The technology all supports the "big ship" idea - with g-compensation and "thrust plates" meaning you don't have to use fuel to turn, a 3,000,000 dton BB can manuver just as well as a fighter. It's not just a lack of atmosphere that does it, that whole "cheap plentiful fusion power" thing and the "fuel, we don't need no steenkin' fuel we've got MAGIC PLATES" concept from MT really puts a kibosh on small ships. (Yeah, yeah, I'm a Stutterwarp and spin habitat guy myself, I admit.)

I suspect it's not all technology - Traveller is supposed to be the Age of Sail in space, and back then they didn't have "fighters" but they did have sloops and frigates doing boarding actions and so on. I also suspect that there was a few guys at GDW who were big fans of the age of the battleship.

The problem, of course, is that such a universe is dreadfully dull (in my opinion). Once you start extrapolating out stuff for 'future realism' you stop needing small tramp freighters, large human crews in starships, and a host of other stuff, too.

 

[Blue Ghost]

epicenter00; that's a pretty good post. I wish I'd thought of that when we did our space oriented adventures.

This is why I usually referenced movies instead of reality to get a template for Traveller material. The only exception were with personal weapons (various assault rifles and so forth). For space combat the thought was the smaller youi were the more maneuverable you were.

More later. I have to go to work tomorrow, and hence must sleep.

Great thread

 

[stofsk]

Originally posted by Sulpicius:
I'm looking for some different thoughts on this matter. Are fighters important against warships in YTU, or are they relegated to recon and small vessel (read: PC-ships) interdiction duties? Why do you choose to cast small craft in these roles?

Doesn't it depend on the mission? Fleet vs Fleet, your fighters aren't going to do much against battleships. In those sort of cases, something like Star Wars shows us that big ships fight other big ships, and little ships try to get out of the way and survive long enough to do strategic damage.

If the mission is an invasion, then you want your big ships to interdict the planet after dispatching the defenders, while having small ships capable of flying in an atmosphere can provide close air support to ground forces.

If the mission is patrol/anti-piracy, then you won't really use battleships to begin with.

I agree with the overall sentiment expressed here, fighters in space are not analogous to fighters in atmosphere, they're more equivalent to torpedo or PT boats. I actually think space fighters are somewhat overused in sci-fi so I don't mind the big ship feel of Traveller. I don't eliminate them entirely from MTU, but I try to think of reasons to use them beyond the cliche of 'big ship launches fighters and then sits there waiting to get hit by a nuke while single-seat fighters fly and die in space'. It's such a transparent 'battle of midway' motif.

 

[mbrinkhues]

Some more roles for fighters (again based on GT):

+ Anti missile defence

Fighters can act as part of the anti-missile screen adding an additional tier to the heavy units defence. Make the fighters stealthy and fast, light on armor (GT has a mass based thrust system) and sen them missile hunting

+ Turret hunting

In GT turrets on large craft have less armor than the hull so they can still move. Send your fighter in really close and have them hunt turrets, weakening the enemys anti-missile defence. For added style you might use X style thruster mountings with a small cockpit module where the pilot stands instead of sitting.

+ Shuttle escort

When your customs gig goes out to inspect a potential smuggler nothing says "don't do something stupid" better than two-four high-g fighters flying cover. More than enough firepower to bring down the average merchantman

+ Q-ship

German style Q-ships in WWII sometimes carried small S-Boats as a fast-strike craft to catch tankers etc that could outrun the rather slow merchantman conversions used by the german navy. Fighters could do a similar job in frighter based Q-ships (say based on the 2000dt Imperialines frighter)


On weapons:

GT has the heavy laser. It takes up more space (only 1/turret) but has a much longer range and heavier damage. Makes a nice weapon for fighters going pirat/small ship hunting.

 

[Arthur Denger]

Originally posted by whartung:
Maneverability has to do with, at a gross level, simply thrust to mass ratios. Since you can make a fighter with 6G of acceleration and 100Kton battle ship with 6G acceleration, guess what -- they're both, essentially, equally maneverable, since they both can apply the 6Gs in their appropriate directions. With proper scaling of the assorted thrusters and what not, maneuverability is the same...

The only advantage a smaller ship has over a larger ship is its size. It's simply a smaller target, and thus harder to hit...

...But, anyway, as I recall, agility was mostly excess power in the plant and not much else in game terms.

Again, I see this as a flaw in the basic rules of the game. It's been a long time since high school physics class, but doesn't the inherent inertial effect of mass play an crucial part (velocity!) in the maneuverability equation? Again, I think the CT/MT rules completely fail to account for this.

It really has absolutely nothing to do with the aircraft-atmosphere analog, nor with sensors and turret weapon response times. Maneuver procedures outlines in LLB2 indicate starships in Traveller alter their vectors by spinning upon their central axes and aiming their grav plates 180° from the new vector desired. This assumes constant acceleration to midpoint, followed by constant acceleration at a 180° vector: this is hardly good fuel economy, and it is highly doubtful that any spacecraft would be operated in this manner, except under the most extreme circumstances!

I realize, in game terms, that simplicity is good, but it is this very loophole in the rules which makes a multi-million ton capital ship every bit as maneuverable as a 10 dton fighter, or a missile, for that matter. Convince me otherwise, because I simply don't buy it.

 

[Whipsnade]

Originally posted by Arthur Denger:
Again, I see this as a flaw in the basic rules of the game. It's been a long time since high school physics class, but doesn't the inherent inertial effect of mass play an crucial part (velocity!) in the maneuverability equation? Again, I think the CT/MT rules completely fail to account for this.

Mr. Denger,

It has been a long time since those high school physics classes, hasn't it?

If a vessel has enough power to accelerate at 6 gees it can accelerate at 6 gees. Period. Whether the vessel in question is 10dTons or 1 million dTons doesn't matter. If it can pull 6 gees, it can pull 6 gees. Any concerns regarding inertia are unfounded. By definition, the thrusters in question on both the 10 dTon and million dTon vessels can handle the inertia inherent in either because they both can accelerate at 6 gees.

This assumes constant acceleration to midpoint, followed by constant acceleration at a 180° vector: this is hardly good fuel economy, and it is highly doubtful that any spacecraft would be operated in this manner, except under the most extreme circumstances!

Doubtful? Oddly enough that exact flight profile is described in both text and diagram on page 10 of LBB:2 Starships. Let me quote: The three travel formulae assume constant acceleration to midpoint, turnaround, and constant deceleration to arrive at the destination at rest, as shown in the diagram above.

I realize, in game terms, that simplicity is good, but it is this very loophole in the rules which makes a multi-million ton capital ship every bit as maneuverable as a 10 dton fighter, or a missile, for that matter. Convince me otherwise, because I simply don't buy it.

You don't have to 'buy it' any more than you have to 'buy' gravity. It's science, your beliefs are irrelevant.

The only 'loophole' here isn't that vessels of greatly differing sizes can accelerate at the same rate as long as the engineering plant in each allows it. The 'loophole' is Traveller's upper limit of 6 gees. That allows a larger vessel to match smaller vessel's performance. Remove the 6 gee cap and fighters will maintain higher gee ratings and agilities across the TL span.

If you need to use Traveller to play BSG or Star Wars, simply limit TL to below TL12.


Have fun,
Bill

 

[The Oz]

Originally posted by Arthur Denger:

It really has absolutely nothing to do with the aircraft-atmosphere analog, nor with sensors and turret weapon response times. Maneuver procedures outlines in LLB2 indicate starships in Traveller alter their vectors by spinning upon their central axes and aiming their grav plates 180° from the new vector desired. This assumes constant acceleration to midpoint, followed by constant acceleration at a 180° vector: this is hardly good fuel economy, and it is highly doubtful that any spacecraft would be operated in this manner, except under the most extreme circumstances!

I think you are misunderstanding things here. A ship in TRAVELLER makes an interplanetary flight this way (accelerating constantly to a turnover half-way through, and then decelerating constantly to a velocity match with the destination) to get minimum travel time.

It would be possible to use less fuel by accelerating to some certain speed, halting acceleration and coasting towards the destination, and then, at some necessary distance, flipping and decelerating to a velocity match with the destination. But this technique will greatly increase travel time and since TRAVELLER ships don't have to worry about fuel for their maneuver drives (depending on which ruleset is used in a particular TU) it is an assumption that ships will choose the minimum-time flight profile as a matter of course.

Note that you do have to match velocities with the destination, so no matter which flight profile a ship chooses it will have to flip 180 degrees and decelerate at the end of the voyage.

 

[Ptah]

Originally posted by Arthur Denger:

Originally posted by whartung:
Maneverability has to do with, at a gross level, simply thrust to mass ratios. Since you can make a fighter with 6G of acceleration and 100Kton battle ship with 6G acceleration, guess what -- they're both, essentially, equally maneverable, since they both can apply the 6Gs in their appropriate directions. With proper scaling of the assorted thrusters and what not, maneuverability is the same...

The only advantage a smaller ship has over a larger ship is its size. It's simply a smaller target, and thus harder to hit...

...But, anyway, as I recall, agility was mostly excess power in the plant and not much else in game terms.

Again, I see this as a flaw in the basic rules of the game. It's been a long time since high school physics class, but doesn't the inherent inertial effect of mass play an crucial part (velocity!) in the maneuverability equation? Again, I think the CT/MT rules completely fail to account for this.

Actually it might not under the concept of the M drive in CT. The M drive providing a net accelleration of any mass (probably some upper limit) within a given volume. Of course this is not the Newtonian physics taught in high school because we do not know of such a reactionless drive. The M drive can be made consistent with the conservation of energy and momentum, althoug I don't think the canon description necessarily does.

Maneuver procedures outlines in LLB2 indicate starships in Traveller alter their vectors by spinning upon their central axes and aiming their grav plates 180° from the new vector desired. This assumes constant acceleration to midpoint, followed by constant acceleration at a 180° vector: ...

I've also found this doubful or would make small ships more manueverable than large ships as the g force at the end of a spinnig ship can get large (of course depending on how fast you spin) maybe not so large as to break the ship but large enough to smash a person. Work arounds/assumptions include of course gravitic technology that can counteract this, or merely placing the crew at or near the axis of rotation.
IMTU I've always assumed there is not one grav plate but two or more. No need to spin just shunt power to the forward plate to reverse direction, so no need to spin. That being said, fighters IMTU don't need these extra plates so they get a savings on drive volume.

I realize, in game terms, that simplicity is good, but it is this very loophole in the rules which makes a multi-million ton capital ship every bit as maneuverable as a 10 dton fighter, or a missile, for that matter. Convince me otherwise, because I simply don't buy it.

I wouldn't call it a loophole so much as what might naturally follow from the M drive concept where mass makes no difference to drive performance. Remove the need to spin to change direction and a multi-million ton ship can be just as manueverable as a 10 ton fighter, but the fighter might have smaller % dedicated to drives. It does not feel right IMHO and goes against everything we know because we only know reaction drive physics.

IMTU I like the idea of reactionless drives, but also like the idea of more manuverable small ships. So besides the smaller drive % mentioned above I postulate higher G M-Drives working for smaller ships.

 

[mike wightman]

The acceleration compensators in Traveller ships cancel out all lateral g-forces. The ship only has to worry about which way its main drive is pointing.

Realistic?

No.

But then, neither is the jump drive, artificial gravity etc. etc.

 

[Zob10701]

I've read most of the posts here and I have a question—pardon the dumbspeak...

Manuever drives are the big, magical, glowy things that make ships go when they're not in jumpspace, right?

And most of the time, they're mounted on the rear of whatever ship they're pushing, right?

So, how do they make a ship change direction instantly? That is, I realize that being reactionless, they don't have to be pointed 180º from the direction that you want to go in (or do they?), but how do they do it? What exactly governs the direction change?

I'm asking this from the perspective of an artist with an interest mainly in how this would look visually, like my previous question on the color of plasma/fusion fire.

 

[Ptah]

Originally posted by TheVamp:
I've read most of the posts here and I have a question—pardon the dumbspeak...

Manuever drives are the big, magical, glowy things that make ships go when they're not in jumpspace, right?

And most of the time, they're mounted on the rear of whatever ship they're pushing, right?

So, how do they make a ship change direction instantly? That is, I realize that being reactionless, they don't have to be pointed 180º from the direction that you want to go in (or do they?), but how do they do it? What exactly governs the direction change?

I'm asking this from the perspective of an artist with an interest mainly in how this would look visually, like my previous question on the color of plasma/fusion fire.

Some say the glow is actually dumped waste heat from the power plant, it is kept at the back to minimize a ships signature to those ahead of it to the extent possible.

Frankly, canon drawings all seem to be drawn from the requirements of a reaction drive in an atmosphere, maybe this is based on our preconception of what "engines" should look like. Heck even some engines show nozzle like structures.

It might also be related to the reason ships are always shown top side up, and all ships in a group have their top sides up and their bottom sides down. It probably just "looks right" to us even though in space there is no need for this at all.

In space maybe no one can hear you scream but if your ship blows up it better make a satisfactory boom or it's just not cool.

All just planet-hugging TL8 folks preconceptions.

 

[Zob10701]

OK, so now I'm home and broke out my copy of Starship Operator's Manual which says that thruster plates can attain full propulsion only in a single direction, usually due aft, but can provide thrust in any direction.

It goes on to break it down to 25% thrust perpendicularly and 10% negative thrust, to "back up."

So now, here's another scenario:

You've got a big, lumbering battlewagon and teeny, little fighter.

Both have got 6G maneuvering.

Shouldn't the teeny, little fighter have an advantage over the big, lumbering battlewagon as long as it applies full aft thrust to zip along the battlewagon's lateral line, where the battlewagon can only apply 25% thrust?

 

[aramis]

The only advantage not being mentioned of smaller craft is the higher rates of rotation possible on smaller frames without spin-stresses.

Since I'm too lazy to look up the maths involved, it should suffice to say that a small craft of X-G's can whip it's ends around far faster than a large ship of X-G's, simply due to the fact that the large ship has to keep the ends from exceeding X-G's of centrifugal force.

Getting a small craft to 1G is revs per second; getting a 5KTd destroyer is revs per minute. I doubt the A/G will compensate for the structural stresses, and I know most of the combat rules don't reference the need to bring the nose around, etc.

Given that the hull of a battleship is stressed typically to match the G's of the drives (TNE/T4), this severely limits their ability to withstand rapid changes of FACING. Given that FF&S designs also generally use reaction thruster systems, with VERY limited off-axis thrusts (typically RCS only), we're going to affect combat maneuvers slightly that way.

It's not a major issue.

Bill's right in that the drive systems are the same, so the performance envelopes can be the same; given that naval ships are designed for crews to be functioning in a "shirtsleeve" environment, while fighters can be designed for a "G-Suited" environment. With G-suit support, operating at compensated+3 G's for extended times is doable, and compensated + 6 to 9 for short times as well.

Big ships, however, need to keep off-axis G's to compensation or less, and on-axis to compensation+native or less.

Based upon CT, however, it appears that CT links the compensation and the drive together. MT technically doesn't, TNE/T4 explicitly don't. So, given the CT paradigm, we should be able to pump fighters up more, but the rules, being left quite simple, didn't cover "special circumstances."

Typical FF&S fighter designs (mine and others) range from 6-7 G TL 10 fighters through 15+G TL 15 fighters requiring G-suits. ISTR a TL14 TNE design at 20G's, but I also recall something was overlooked, but can't recall what.

 

[flykiller]

The only advantage not being mentioned of smaller craft is the higher rates of rotation possible on smaller frames without spin-stresses.

a very valid point, if the drives push the ship around. imtu the maneuver drives simply create a gravitic field and the ship "falls" in the direction desired. whether the hull is sheet metal or five foot thick polymers, the effect and agility are the same.

nevertheless, the point is worth considering. in HG2 the hull itself requires no dtonnage. perhaps it should - .02 for each G of agility. also, ship hull size codes have to-hit ratings:

<9: -2
<A: -1
<L: 0
<P: +1
etc

perhaps these can be associated with max agility ratings.

<9: max agility 6
<A: max agility 5
<L: max agility 4
<P: max agility 3
etc

note that this would be agility for combat purposes, not maneuver speed for transit purposes. thus the battle wagon can still transit at 6G, but when it starts trying to twist and turn to confuse or dodge incoming fire it is limited to agility 3.