Agility and the CT manuever drive

[far-trader]

Well, daring to continue topic divergence, it's been a while and possibly I misread or misremember it but I thought the idea in FF&S1 re lasers and gravitic focus was simply that it replaced the need for a huge diameter mirror focus to achieve the long range needed. I don't think there was any mention of creating some gravitic tunnel.

 

[robject]

No worries, the thread was created by a player in my PBEM about how his player can fly a launch, so if it runs down some rabbit holes, fine by me

It [gravitic focusing] did replace the need for a huge diameter bore/focus thingy, yes... in fact, the diameter of a non-gravitic laser would be so absofreakinglutely huge that it wouldn't be Traveller. That sucker would be wider than the Far Trader is long. And don't try to reenter with that thing.

It wouldn't be anything related to the sci-fi we're used to... and the laser sizes we're used to seeing wouldn't have but a fraction of the ranges we use in Traveller combat. Hence the gravitic focusing element.

FFS1 does permit non-gravitic lasers, on the off chance that someone would want to play a sci-fi game with shorter combat distances.

Sigg, do you know off-hand what those closer ranges would be?

The more I think about it, the more I like the idea of X-Ray lasers being present at an early tech level.

 

[robject]

Given 1mj = 1MW/sec;

Given 40mj/cm2 is required to damage a civvie ship hull.

Then what are the power requirements of a standard laser?


If I assume a power efficiency of 50% at TL12 (5xTL-10; nice breakpoints), then the input power should be 80MW.

A standard turret has 3 slots. 3 lasers in a turret would require 240MW... in short, 1 EP.

THEREFORE,

I'm thinking that for MTU, every socket which mounts at least one laser should have 1 EP designated to it. I'll assume that the "remaining" 10MW doesn't exist -- the lasers require a bit more than 80MW, the turret has some high-power engineering requirements, shunting heat away to ceramic coils introduces inefficiencies, blah blah.

Problem:

In High Guard, a pulse laser requires 1 EP, right? And a beam laser requires 2 EP? Well, do I have to go back to the drawing board?


Notes on laser efficiency:

At TL9, laser efficiency is 35%, meaning a 40mj laser requires appx 114 MW. Assuming there's always only 1 EP per turret, a standard turret at TL9 can only mount 2 lasers.

Conversely, efficiency at TL15 is 65%: 62MW per laser. This justifies a barbette: four lasers in a barbette takes 248MW, with a slot left over for something that doesn't take so much power.

Notes on hull armor:

Taking the T4/T20 route, hull armor would 'absorb' damage points to its given armor factor (AF); remaining points would actually cause damage.

All armor has a damage threshold, in megajoules. For civvie ships, the armor threshold is 40mj, which doesn't provide defense against weapons. Therefore, the standard civvie ship would have an AF of 0: all starship combat damage causes damage.

So then, there's a direct mapping of the armor's energy threshold (E) and a ship's AF: AF = [E/10]-4. Not pretty, but not bad either.

Anyhow, if an armor can withstand 80mj, the AF increases to 4. The ship absorbs 4 points of damage from every hit. That's a powerful armor (I wonder if it's too powerful?).

 

[Fritz_Brown]

Well, robject, if there's equations, then it's not handwavium... it's FPM: Freakin' Physics Magic!

And, I know there would be some loss in a laser path, but I don't think you would really need huge mirrors. You just need to postulate a really good source - really small point sources that exactly align the photons. I seem to recall they are approaching this point with low-power lasers for fiber-optics. Ironically, if that concept is taken to it's logical conclusion, you get no barrel on your laser - just a spot where the light originates.

Hey, does this change the argument about hardpoints?!

 

[robject]

I dunno! As we deviate further from Fire, Fusion, and Steel, it kinda ceases to matter, eh?

...which is good in my opinion, since FFS has been a thorn in my side as much as it's been a blessing. It just goes to show that there's no reason to guess what future tech will be like for an RPG -- unless it makes the rules hang together well.

You're more of an authority on it than I; I've got no clout in the physics world. I see you might actually deal with optic-related things in the Real World.

 

[far-trader]

Hardpoints have more to do with the need for an area on the hull that has a clear line of sight to the target and can cope with a lot of stress to slew the turret to track.

What you seem to be leaning towards there Fritz is the Star Trek phaser which seems to often be built as a ring of point emitters with power channelled to the point on the ring facing the target (and presumably with many points at each arc to allow declination and elevation. Very solid state handwavium

Anyway...

 

[Fritz_Brown]

Ahhh, yes, that would be an explanation for that concept, wouldn't it. (Still wouldn't explain the idea of the light running around the ring before zipping off toward the target....)

And, of course, the argument about hardpoints is the whole tonnage v. surface area thing. Now you don't even have the slewing machinery bit to fall back on. As you said, very solid state. You could have little knobs all over the ship that encompassed the lasers, with nothing more than a targetting sensor and the power hookup.

Of course, if you combine this with the computer modernization, you could free up enough cargo space to even make a J2 ship break even with per jump pricing....

[sneaking out the back....]

 

[robject]

Hmm. You and Marc must think alike, 'cuz T4 didn't use hardpoints. You just kept sticking guns on the ship until it was full.

 

[parmasson]

Heretics! Blasphemers! NO TURRETS?! EMITTER POINTS?!

<Mumbles inaudibly and slinks away with his LBBs petting them gently>

 

[far-trader]

Guess I shouldn't mention the nuke pumped x-ray laser turret I'm playing with then

Same basic idea as the nuke pumped x-ray laser missiles only in a turret form. Imagine a regular looking laser turret only instead of running a power feed to it and needing the reactor for juice it has a magazine fed firing chamber which uses small nukes and x-ray laser rods like bullets. Nicely elimiates the need for handwavium gravitic focus and also does away with mirrors the size of swimming pools. Voila, we have lasers that work and look like the old turret guns

Of course there is the radiation (damper boxes would be handy) and the requirement of a magazine and ammo. But hey it sounds cool to me!

How deep is this rabbit hole??

 

[parmasson]

Fine.

The jump laser. That is correct, a jump laser.
Using gravitic focusing and plenty of “jump fuel” the jump laser fires a bolt of jump energy with pin-point accuracy to any location within 20,000 km. The only hitch is that it takes 168 hours for the pulse to hit.

One of the silly weapons of the Second Imperium.

 

[mike wightman]

Not as silly as you may think

If you read Fallen Dragon by Peter F. Hamilton you will find the neat idea of partially charging the FTL drive, and then discharging it as a huge gamma ray laser.

Then read this, and see if you can guess what I came up with

 

[Andrew Boulton]

"it has a magazine fed firing chamber which uses small nukes and x-ray laser rods like bullets."

!

 

[robject]

Originally posted by Sigg Oddra:
Not as silly as you may think

If you read Fallen Dragon by Peter F. Hamilton you will find the neat idea of partially charging the FTL drive, and then discharging it as a huge gamma ray laser.

Then read this, and see if you can guess what I came up with

Yowza...

 

[parmasson]

A giant ship pumped laser using the hydrogen from the jump bubble and the P.P.

 

[Fritz_Brown]

Isn't the bomb-pumped laser turret akin to the "fusion-bomb" propulsion method? Only you're doing it INSIDE the ship?!

 

[far-trader]

On a much smaller scale yes. I still haven't worked the numbers to see just how big a BANG it would be but it sounds like fun

The part of it that I like is it makes big laser guns work without magic (unless we need magic to keep the BANG part from destroying the ship).

I also like that you don't need a power plant running 24/7 to power a weapon you might only need for an hour once or twice a year as a merchie. And as a combat craft you don't waste that power that could be better used for agility or something else.

Hmmm, a bay weapon version, 50 or 100 tons of nuke powered laser

OOOOO, spinal version

 

[parmasson]

Good grief

 

[robject]

Originally posted by far-trader:

I also like that you don't need a power plant running 24/7 to power a weapon you might only need for an hour once or twice a year as a merchie. And as a combat craft you don't waste that power that could be better used for agility or something else.

"What, all your traders are armed? Where's the fun in that?"

Or...

"You don't need a more powerful power plant. Just don't maneuver when you're firing."

Or...

"But a more powerful power plant means it can take more hits before it's dead in the water."

 

[mike wightman]

Originally posted by Kurega Gikur:
A giant ship pumped laser using the hydrogen from the jump bubble and the P.P.

Yep

I calculated from High Guard that a jump equipped ship stores 18EP per jump number per 100 tons of ship in its capacitors - so use this energy for one big laser blast instead, or a few smaller ones
It uses up all of your jump fuel, but what the heck