Alternate Launch Tube rules

[phavoc]

Launch tubes, by the book rules, have always seemed rather useless to me, especially in CT where you would RECOVER your craft via tubes... shudder.... all you need is a damaged craft blocking your only egress from the hangar deck to ruin a carrier's day. Sounds cool, but quite impractical. Kind of like screen doors on a submarine, to catch the ocean breeze when you are cruising on the surface at night to recharge the ol batteries...

So here's my take on Launch tubes - They are electro-magnetic catapults capable of launching small craft at higher than normal speeds. The craft retain their higher launch velocity, or whatever their thrust rating is, whichever is higher. In the event that their launch speed is higher than their thruster capability they retain the higher speed so long as they continue in the same general direction of their launch (typically towards an enemy). The turn they maneuver to engage any target is when their speed drops to their normal thruster rating.

Launch tubes may come in any size. For every 10m of launch tube installed, a small craft may launch at 2G. The maximum length of a launch tube is 120m, setting the maximum launch velocity at 24G. A launch tube displaces the largest tonnage of small craft launched, +20%, for every section installed. Launch tubes become available at TL10. Launch tubes do not benefit from TL difference for reduced size/cost.

TL-10: Max 8Gs launch velocity, may launch up to 20 small craft/turn, requires 1,500 energy, 50MCr per section
TL-11: Max 10Gs launch velocity, may launch up to 24 small craft/turn, requires 1,800 energy, 60MCr per section
TL-12: Max 12Gs launch velocity, may launch up to 30 small craft/turn, requires 2,000 energy, 70MCr per section
TL-13: Max 16Gs launch velocity, may launch up to 30 small craft/turn, requires 2,300 energy, 80MCr per section
TL-14: Max 20Gs launch velocity, may launch up to 32 small craft/turn, requires 2,600 energy, 90MCr per section
TL-15: Max 24Gs launch velocity, may launch up to 32 small craft/turn, requires 3,000 energy, 100MCr per section

Text needs to be cleaned up and better defined, and probably could stand a little more explanation on how the catapult works. I wasn't sure about putting tonnage limitations in by TL, though that's entirely within reason. And this doesn't at all handle the movement aspect (i.e. newtonian physics). One way to sort of address that would be to allow small craft to ADD their existing thrust ratings to the catapult speeds. Course you'd be making some might fast small craft, at least until they actually had to start fighting.

 

[AnotherDilbert]

Workable! These launch tubes are certainly cheap enough to be used.

At around twice the tonnage of the craft and firing 20+ craft per round instead of ten times the tonnage firing 1 craft per round the are around 100 times more effective / dT than the current ones.

They are electro-magnetic catapults capable of launching small craft at higher than normal speeds. The craft retain their higher launch velocity, or whatever their thrust rating is, whichever is higher. In the event that their launch speed is higher than their thruster capability they retain the higher speed so long as they continue in the same general direction of their launch (typically towards an enemy). The turn they maneuver to engage any target is when their speed drops to their normal thruster rating.

But acceleration is not speed. You can give them a shove out the tube, but that acceleration end as soon as the craft leaves the tube. More or less any initial speed the craft are given is insignificant compared to the massive acceleration Traveller craft are capable of.

But that first turns acceleration saves reaction fuel in the fighter, and that is a great advantage in itself.


By achieving the initial speed of 24 G * turn in a fiftieth of a turn the craft are accelerating at something like 1200 G in the tube. Hence you have also postulated almost infinitely capable inertial compensators, but since we have already upgraded the inertial compensators from max 6G to at least 25G in this edition, that is perhaps not that great a leap.


I'm assuming that ships have Inertial Compensators (so we are not tossed around when the ship accelerates), and Artificial Gravity (so we are pressed to the floor and not floating around in Zero-G) even if that is not discussed in the Core book as far as I can see.

 

[phavoc]

Yeah, there is that hole there about accel, bit since we don't talk about deceleration in combat, I wasn't going to dither the point too much. Can you imagine two fleets approaching each other after having boosted for a few hours? Theit engagement time would be quite small, and then it would be half a day before they could engage again. This is where it's ok to hand wave since we already hand wave it so many other places.

 

[AnotherDilbert]

We all have our hobbyhorses. I would greatly prefer if we kept acceleration and velocity separated. Since the current combat system ignores velocity completely for simplicity, I think we should keep it that way.

Giving the fighters an extra rounds worth of acceleration is good enough.

 

[phavoc]

Yeah, that would be fair. In that case, since it's a round, I guess you could let a fighter add their normal thrust rating to things and in one turn they could potentially knock a couple of range bands off.

 

[AnotherDilbert]

That sounds like fun, but I fear that it might be little much.

A good fighter can accelerate at 9G +16G = 25G. If we add the acceleration from the launch tube, 24 G, we get an available 49 G in one turn.
In the same round as the carrier manoeuvre into Very Long range we launch the fighters at 49 G and we are immediately at Adjacent range and in Close Combat. So in one single Manoeuvre Phase the fighters go from Distant Range (carried) to Adjacent (in close combat). That is too good...

 

[Nerhesi]

Lookin forward to making launch-tubes workable

 

[Condottiere]

I always thought excreting fighters at the other end would be more practical.

 

[Nerhesi]

Lets keep in mind that the "good" 25G fighter is actually the top of the line, super expensive, with only a little stamina sort of fighter. I believe you end up with 1 hour (10 combat rounds) of 25G acceleration - I can't find my play test file no more!

 

[phavoc]

Lets keep in mind that the "good" 25G fighter is actually the top of the line, super expensive, with only a little stamina sort of fighter. I believe you end up with 1 hour (10 combat rounds) of 25G acceleration - I can't find my play test file no more!

My idea with the launch tube was that you could go and make the best of the best, but you could also do 'average' ones for carriers whose task is escort or scouting. Only the assault carriers would need all the bells and whistles. People don't realize that low-risk areas will rarely get top of the line modern craft. Backwater sectors will be flying around in TL-14, or even TL-13 craft. Which is still more than enough to handle most small brush-fires and the odd pirate.

 

[AnotherDilbert]

Lets keep in mind that the "good" 25G fighter is actually the top of the line, super expensive, with only a little stamina sort of fighter.

Yes, a normal fighter, like a Typhoon, F15, F16, F18, F35, etc.

I believe you end up with 1 hour (10 combat rounds) of 25G acceleration - I can't find my play test file no more!

Something like that, but when it takes 3 - 6 rounds to close in to the enemy that is enough.

 

[AnotherDilbert]

My idea with the launch tube was that you could go and make the best of the best, but you could also do 'average' ones for carriers whose task is escort or scouting. Only the assault carriers would need all the bells and whistles. People don't realize that low-risk areas will rarely get top of the line modern craft. Backwater sectors will be flying around in TL-14, or even TL-13 craft. Which is still more than enough to handle most small brush-fires and the odd pirate.

Agree, but Imperial tech progress is rather glacial. If I recall correctly (unlikely) the Imperium have been at TL15 for something like a century. Even the old, old equipment will be early TL15.
But even the navy buys lower TL stuff since TL12 shipyards for maintenance and repair are much more numerous, but that is more likely to be support ships than combat ships.

 

[Reynard]

"By achieving the initial speed of 24 G * turn in a fiftieth of a turn the craft are accelerating at something like 1200 G in the tube"

Launch tubes don't have to launch craft at huge speeds. The control station sets acceleration as needed. Just like naval catapults that launch planes fast enough to achieve flight speed relative to the speed of the vessel, space and starship tubes will launch craft at an acceleration to achieve a mission velocity which takes into consideration the launching ship's own velocity and vector. If you launch at 1200gs, the craft now needs to spend a lot of time countering it before reaching it's destination or it sails off... that way.

 

[AnotherDilbert]

"By achieving the initial speed of 24 G * turn in a fiftieth of a turn the craft are accelerating at something like 1200 G in the tube"

Launch tubes don't have to launch craft at huge speeds. The control station sets acceleration as needed. Just like naval catapults that launch planes fast enough to achieve flight speed relative to the speed of the vessel, space and starship tubes will launch craft at an acceleration to achieve a mission velocity which takes into consideration the launching ship's own velocity and vector. If you launch at 1200gs, the craft now needs to spend a lot of time countering it before reaching it's destination or it sails off... that way.

I think the basic idea was to point the launch tubes at the enemy, shooting the fighters out at great velocity to give the fighters a head start in reaching close combat with said enemy.

 

[phavoc]

"By achieving the initial speed of 24 G * turn in a fiftieth of a turn the craft are accelerating at something like 1200 G in the tube"

Launch tubes don't have to launch craft at huge speeds. The control station sets acceleration as needed. Just like naval catapults that launch planes fast enough to achieve flight speed relative to the speed of the vessel, space and starship tubes will launch craft at an acceleration to achieve a mission velocity which takes into consideration the launching ship's own velocity and vector. If you launch at 1200gs, the craft now needs to spend a lot of time countering it before reaching it's destination or it sails off... that way.

I think the basic idea was to point the launch tubes at the enemy, shooting the fighters out at great velocity to give the fighters a head start in reaching close combat with said enemy.

Yup.

And to, yanno, actually make launch tubes have more value. Unreasonably restricting launch rates from hangars to give launch tubes a reason to exist isn't a good reason to have launch tubes. In defense of the AHL hangar deck, with the fighters stored like bullets in a belt to be "fed" to a pair of launch tubes, that wasn't a bad idea. Recovery of said fighters via the launch tubes... bad idea. And if you are going to build that big tube, why did it have to be so long when it never imparted anything of value to the craft, other than launching? In that case you could build the equivalent of a snub-nosed .38 special and saved a LOT of tonnage.

 

[Reynard]

I believe the idea back then was a 1200g launch would crush a person to goo since thrust and compensation were maximum of 6. Quite possibly a long launch tube gradually built up acceleration. As to recovery by the same tube system, and the recovery area was NOT the launch area, it showed efficiency of resources. Obviously the space control technology is advanced enough for precision recovery and there is a secondary recovery system for damaged craft.

 

[phavoc]

It's actually no different under the rules today. There is no acceleration curve handled in the 6 minutes. And the length of the tube would allow for rapid acceleration. It need not be 0 to 25G instantly. This is where the hand wave of the tech comes into play too.

If we can have afterburners that can add G's worth of acceleration to multi-million ton objects in space, we have the tech to fling some guy and his teeny little ship out of a tube at 25G's.

 

[AnotherDilbert]

Um, you would gradually build up velocity with a constant bearable acceleration.

25G will quickly kill you, Inertial Compensators are absolutely necessary, and the problem goes away.

And they are not afterburners, the reaction drives are simply booster rockets.

Sorry for being petty about the details...

 

[phavoc]

I never said compensator weren't required. Anything over 6G, especially sustained, cannot be handled by a human body. Very temporary spikes in the 9bto 10G range render pilots unconscious for brief periods. 25G would kill anyone without a compensator.

The point about not doing 0 to 25 was so the acceleration had a curve to it, nothing more.

 

[Condottiere]

Normal acceleration can come into play once you've cleared the tube, in what, two seconds?