Lasers: Are they silent? Are they visible?

[far-trader]

Originally posted by jappel:
If memory serves, the cartridges also contain coolant to alleviate the overheating problem. Drake gives a reasonably detailed explanation in one of the earlier Slammers books or stories.

Overall, I think this is an awesome idea, and getting rid of the backpacks eliminates one of the main reasons players seem to eschew laser small arms.

John

Sounds very like the CLC description from TNE iirc. The cartridges contain the chem for the reaction and the cooling purge cycle, and they are hot and toxic which is why you don't want to use them in the confines of starship or when not wearing sealed armor (combat armor or better).

 

[Todg]

Originally posted by tucker2:
The thing that's cool is you could also go kinda retro, lever action or pumps for rifles, or revolvers or pepper-box configuration for pistols. This sorta thing gets better mileage in a Firefly-esque sort of game. It sorta has that visceral appeal that the general TU player misses with the canon laser weapons. Hell, maybe I'll just do that. The chem lasers have a better per-shot damage and pen, but cannot burst fire-- only semi-auto unless you got a MG equivalent. Or maybe not. I have to get some coffee.

I like. Cartridge lasers have more damage and good penetration, but at the expense of heat buildup. Ity fots with the whole 'advatages, disadvatages' this and will appeal to certain types. Sure, the cartridge laser has alower rate of fire, but it got long range, zero time of flight and no windage or drop. Makes it the superior sniper weapon.

No recoil makes it good for zero G too.

 

[Straybow]

FF&S says that CLC lasers aren't used for starship weapons due to the hazardous chemicals involved.

Ummmmmm, the lasers aren't in the ship per se, and the purged chemicals would be vented to vaccuum. If it is the stability of the stockpiled cartridges that has you worried, this isn't the lowly 20th century. I should think a few millennia of progress, however halting, sufficient to eliminate that as a safety concern.

If cartridges have a limited shelf life of 10 years or something it is part of the maintenance costs. I would be live-fire practicing enough to use ammunition faster than it could expire (but that's just me). Don't tell me magazine capacity is a problem; one dT would be sufficient for thousands (maybe tens of thousands) of cartiridges.

Still think heat dissiplation from the emitter is a problem? Use a Gatling-type design. If each barrel fires only once during the interval that a normal beam weapon fires once, you have several times the firepower.

Induction lasers need significant recharge time between shots. It's the same reason why armies went from single-shot slugthrowers to cartridge repeaters to full auto capable assault rifles. The ability to saturate the target area with fire is critical to weapon effectiveness.

 

[mike wightman]

I think the real reason (that there are no CLC shipboard weapons) is that no one could be bothered to design them and to include them in the standard designs in Brilliant Lances.
There's nothing to stop someone accepting the challenge...

 

[far-trader]

Nah I think it was a misunderstanding of using the small arms CLC lasers in a confined space, like a ship, and thinking it meant the use of CLC lasers for a ship's weapons, as in turret mounted. I guess I could dig out FF&S and TNE and check rather than rely on faulty memory paths

As for big CLC lasers I think I designed a vehicle version once upon a time, now where would it be???

 

[mike wightman]

I wonder if there are any vehicle mounted CLC lasers in the RC Equipment guide or Striker 2?
<edit> I've found a TL14 Zhodani X-ray laser armed grav tank in Striker 2 that has 35 shots/rounds?
Anyone know where its full stats can be found?<edit>

 

[Badbru]

Three reasons why there are no ship mounted CLC
(chemical laser cartridge) laser's in TNE;

(1) DEI (Direct energy input) Lasers are superior.
If your powerplant is running you can fire your DEI weapons and you can keep doing it until you run out of fuel. If you had CLC's you'd need a magazine and once you empty that magazine you're done!

(2) Yes you could probably design a turret mount that vented the coolant gases etc directly to space but then you have a thin armor point-the vent. another thrust agent-the vent. And in the event of a magazine hit potential nasty toxic gases spreading through your sealed (well partially sealed) starship. See also point one if you loose your magazine.

(3) At the ranges and intensities needed for TNE
starship combat (usually beyond 1 light second/300,000klm your CLC's for a laser that big would be huge. If you wanted them stored in the turret your magazine would not be large at all.

Having said all that there is one starship that does mount a CLC laser, though it's only the squad support version for use in atmosphere's at NOE altitudes to support landing and retrieving troops. (The Victrix class)

N.B. The squad support lasers' CLC's are 2.7cm x 8cm for a weapon with a 300 metre short range, that's about half the size of a soft drink can, so extrapolate out to 300,000klm

 

[Todg]

Whether or not CLC lasers are used on ships will depend on power densities available. If CLC lasers generate more power per unit volume of ammo or fuel, they will be the weapon if choice. If DEI lasers are, the reverse will be true.

IMTU, I assume that because of scale efficiencies, DEI lasers become the better choice on ships because the fusion power plants can produce more energy for a given volume than can CLC.

In the case of small arms, the case is reversed. CLC lasers give a better power density than batteries.

YMMV.

 

[tucker2]

Since David Drake is getting such good mention, he has a series of books with a swashbuckling bent, 'Igniting the Reaches' & 'Fireships' being a coupla titles. He has ships that use 'cannon' with single shot weapons( okay powerguns) that're similiar. The appeal is mighty good from a genre mixing perspective, and the logical use derives from the not so good powerplants.

Another thought is use of the CLC weapons on SDBs or other ship types that long endurance/station keeping or low energy signature is desirable.

They'd be good for anti-vehicular mines or air defense mines, giving unmanned coverage to the horizon and little chance of spoofing like a missile could be. 2300AD had some kind of unmanned air defense missile thingamajig, it's just an off-shoot of off-route anti-armor mines used today.

 

[kaladorn]

Originally posted by Corejob:
that disrupts tissue will greate an ablative residue which actually blocks further penetration. It appears that lasers, at least the short pulse lasers likely to be used in weapons, won't have the same kind of penetration that KE weapons do.

Interesting. I can sort of see that. But I guess it depends how much power, delivered how fast, and how well sublimated fluid from tissues and vaporized or partially vaporized tissue mass actually does form an ablator.

OK, this is the crux of the question. It goes back to the whole silent weapon discussion. If a laser is relatively quiet and does't leave an incandescent pointer, and it is relatively lethal, then it makes an ideal snioer weapon: Zero time of flight, no drop or windage. It would be ideal. If it has more of a signature than a conventional weapon, it's out.

I think that's why I like them. In zero G/zero P, they're a great choice. In atmospheres that are fairly clear, they aren't bad. In thick, wet, misty or muddy atmospheres, they start to suck. So they have an 'ideal use' and a 'not so ideal' just like projectile guns (though different in where that falls). They also probably suffer optic damage in sandy environments or dusty ones. Even airless moons might offer dangerous little carbon particulates that could gum up things or scour the lenses.

I'd say, except for the backpack (removed at higher TL or if you need fewer shots like a sniper), the laser is a good choice for a sniper. Mind you, by those TL, sniping posts better be shoot-by-wire or shoot-by-comms as sound, flash, and beam backtrack ranging and locating out to be very good. You get a shot, but if you aren't immediately gone, that spot is likely going to go "kaboom".

And of course, as another downside, I assume there is a certain amount of lens care for lasers and there is also the issue that a thin armour (reflec) wearable under clothes can largely defeat the best rifles. That tends to militate against use in non-sniper situations. Reflec won't do much to a slug, and even cloth won't do much against a PGMP.

As to flash, someone on another list poited out that pulse duration length will be a factor. If the energy pulse of the laser is only a thousandth of a second, it will be less of an issue Than something that lasts a second or more.

Yes, but part of the issue here as already noted is the cooling time of the air it burnt through. If that is notable, you have a thermal track.

 

[Todg]

Some more thoughts on lasers.

Metal cutting lasers typically run in the range of 1-6 kilowattsd. This is adequate for cutting thin metals, but I am informed they don't cut tissue all that well unless you have a lengthy exposure. The same is apparently true of the THEL, which operate in the megawatt range - good against missiles because it causes their fuel to explode but supposedly not that effective against human targets.

That seems to suggest that laser small arms are going to have to be hugely powerful to do the kind of lethal damage posited by Traveller.

Any thoughs on what kind of power the typical laser rifle will have?

 

[Anthony]

It doesn't have to be that powerful to damage flesh if the pulse duration is tuned correctly; you want a series of pulses a few microseconds apart, each one powerful enough to vaporize a surface layer of flesh, but insufficient to cause plasma formation. The vaporization creates a crater and forces some flesh out of the way; the second pulse strikes in the crater left by the first. Lethality is still inferior to a kinetic weapon, range tends to be poor due to the very narrow beam required, and penetration can suffer a lot if the beam wanders on the surface of the target, but a ten kilojoule beam could have lethality comparable to a rifle bullet.

Such devices are not really practical to construct today.

 

[Straybow]

/me tweaks quote because people don't use the list feature

Originally posted by Badbru:
Three reasons why there are no ship mounted CLC (chemical laser cartridge) laser's in TNE; </font>

1. DEI (Direct energy input) Lasers are superior.
   If your powerplant is running you can fire your DEI weapons and you can keep doing it until you run out of fuel. If you had CLC's you'd need a magazine and once you empty that magazine you're done!</font>
2. Yes you could probably design a turret mount that vented the coolant gases etc directly to space but then you have a thin armor point-the vent. another thrust agent-the vent. And in the event of a magazine hit potential nasty toxic gases spreading through your sealed (well partially sealed) starship. See also point one if you loose your magazine.</font>
3. At the ranges and intensities needed for TNE starship combat (usually beyond 1 light second/300,000klm your CLC's for a laser that big would be huge. If you wanted them stored in the turret your magazine would not be large at all.</font>

</font>

1. With DEI lasers you can only get one shot in per combat turn. Why doesn't matter (heat dissipation, capacitor charge interval), it's the mechanics of the game and some other type of weapon is needed for rapid fire design. As for running out of ammo, if your firefight lasts that long you're up the creek anyway.</font>
2. The gun itself is no less vulnerable. Ideally the beam and the vent use the same opening. If your opponent can hit either the emitter or the vent from 300k km, you're up the creek anyway. A magazine hit is a hull breach, and whatever chemicals are in there will be swept out with the escaping air. Or the ship is already depressurized and you are in your suit. Magazine bulkheads should be designed to direct explosions outward (the turret is lost anyway).</font>
3. The magazine is never in the turret, although it usually rotates with the turret. The mag is a continuous tray that automatically feeds the cartridges up into the turret to the weapon. The opening is marginally larger than the cartidge itself.</font>

N.B. The squad support lasers' CLC's are 2.7cm x 8cm for a weapon with a 300 metre short range, that's about half the size of a soft drink can, so extrapolate out to 300,000klm

"Half the size" in each dimension: 27x80mm is 46ml, one eighth of a soda can's 355ml. The ship's laser cartridge might be a couple liters, in which case several thousand can fit in a 14kl magazine.

Support weapon range is affected by the system's ability to locate a target and aim, and by attenuation through atmosphere. The former is significantly changed and the latter is eliminated entirely in space combat.

In reality coherent beam dispersion is a function of emitter diameter (edge diffraction), so a laser with 300k km range would need an emitter meters across.

But Traveller (like most space opera) glosses over that and treats it like an energy "projectile" so lasers are long and skinny.

 

[Badbru]

Straybow,
Perhaps Corejob is correct then and it comes back down to power density outputs/ power delivery efficiencies. However the chemicals in a sealed hull is one of the reasons given in Fire Fusion and Steel as to why CLC's aren't used in starships. Yes most people will depressurise prior to battle, where they can. Maybe they don't have the ability to repressurise. Maybe they're hauling atmosphere specific cargo's, maybe they're evacuating troops/civilians and don't have the vacc suits to go around. DEI vs CLC simply eliminates one potential shipboard hazzard, allbeit an argueable one. Also with magazine requirement, no matter the size, you can run into resupply problems. In short you create a potential resupply problem where there need not be one. DEI doesn't need ammo, just power. CLC's are ammo. That's the core arguement for me which I just can't or atleast haven't yet gotten around. The size is variable and I've never designed them to test the theory, but my first post re magazine's wasn't specifically referring to just one firefight. What's say your fleet using rapid fire CLC Laser's loose's it's supply ships, or said ships don't make it to a rendevous, you'd have to return to base. In any event I'm wondering how much TNE designing you've done and how much TNE/Brilliant Lances you've played?
One shot per turn... mmmmn maybe rules play wise, but you can design DEI laser's with any ROF you like up to 800 per turn. and the standard ROF is 10 per turn. Granted these don't alter how many times you "roll for hits" but they do subtract Diff Mods to your chance to hit making Hi ROF laser better for hitting the enemy.
My post, as are allmost all my posts, was specific to TNE, and in that system smaller laser's tend to have poor penetration capabilities. So it seemed odd to me that the Squad support laser was chosen at all for the Victrix class. If you choose a weapon that needs ammunition why not go for a VRF gauss gun or 20 to 40mm auto cannon for the choosen role. VRF Gauss guns have similar performance range and dammage wise and carry lower volume per shot ammunition. An auto cannon could have been made fed from multiple magazine each loaded with different ammunition types for appropriate target type response's. Maybe I'm just biased against Laser's particularly with the treatment they get/got in TNE. I just see IMHO superior weaponry utilising other technologies.
And as an afterthought. TNE ships use G-turns of fuel for maneuvering, so by choosing DEI over CLC's thus negating the need for a magazine, that volume of your ship (even a measly 14kl)can be given over to more fuel, and that's
something experience playing TNE leaves me to desire.
Oh and TNE lasers are big, your standard 3 displacement ton Laser turret has a focal array of about 10 meters squared. So I'm not sure what you meant by laser's being Long and Skinny? maybe you meant the beam itself which is supposedly focussed to 1 square centimeter at point of impact. Which by the way seems a small hole in your hull for the toxic gases from all those ruptured CLC's to vent out through but here I'm just having a laugh with you

I take onboard most of your points though. If you're getting hull breaches you are up the creek.
If your enemy is scrubbing your weapons off your hull, you've also lost your paddle and it's time to get out of Dodge as they say.

 

[far-trader]

You know, getting back to power density/supply and such I had a thought but still haven't found time (or is it desire ) to work out the details.

My idea was what about using jump drive capacitor crystals for small (or big) laser weapons? Is the density better than batteries, hpg, or the other options? Maybe it'd cost more? I'm not sure and like I said still haven't sat down to work it out after the initial idea popped. Anybody care to have a quick go at it?

 

[Badbru]

There is a brief and fairly obscure referrence in FF&S, I think under Black/white Globes, which says that 35% of a ships jump drive is HPG. From that I reverse engineered some power requirement for some of the standard ships jump drives cause they don't seem to need power according to the TNE design sequence (or have I missed something blantantly obvious in the ten plus years I've been designing TNE ships)which allways struck me as odd since there's that reference to Dimming the lighs prior to jump. Anyways from that small by line reference you can determine the power input and megajoules output of the jump drives HPG and hence, though I've not done it, I s'spose you could run any weapon requiring a HPG from it.
Laser's NPAWS and Meson guns alike. Not sure how you could utilise that for other Traveller systems but anyways I hope it helps.

 

[Straybow]

I'm not saying that imperial or system naval forces need to use rapid fire CLC lasers, just that the option should exist.

Do we worry about running out of missiles? Yes, and we still use ships armed with missiles. We avoid ships armed exclusively with missiles.

A triple turret fits only one CLC Gatling gun. You trade 3 shots drawing from ship's power for N shots drawing ammo from a magazine. N would depend on whatever repeat rate is reasonable given higher heat dissipation due to the coolant purge cycle, and the number of barrels (probably 3, so maybe 9-12 shots).

 

[Badbru]

Originally posted by Straybow:
I'm not saying that imperial or system naval forces need to use rapid fire CLC lasers, just that the option should exist.


Do we worry about running out of missiles? Yes, and we still use ships armed with missiles. We avoid ships armed exclusively with missiles.

A triple turret fits only one CLC Gatling gun. You trade 3 shots drawing from ship's power for N shots drawing ammo from a magazine. N would depend on whatever repeat rate is reasonable given higher heat dissipation due to the coolant purge cycle, and the number of barrels (probably 3, so maybe 9-12 shots).

Granted. More options please, options for everything, choice is great. They could be great as point defence weapons or as someone else posted as weapons for stealthy vessels that don't want or can't fit high power output powerplants.
I just don't think they're good choices for primary weapons but I'll acknowledge that's a personal prefference thing IMTU.

Hmmmn yes but they're in canon, Valor class missle boat anyone? Anyway I thought we were discussing two types of the same weapon system not two totally different weapon systems designed for different purposes (excepting that all weapons are designed to damage your enemies

Tripple Turret huh? again I'll repeat; my previous post, as are allmost all my posts, was specific to the TNE system, GDW Traveller: The New Era, using Fire Fusion & Steel design sequences. You seem to be talking about another Traveller Game system maybe Classic Traveller, maybe Mega Traveller, maybe even this new fangled T20?? system.
That is fine cool and dandy. I hope you enjoy it.
It is however not what I use and thus not what I was talking about. I'm not a CT player though I own all the LBBs and original Striker. I'm not a MT player though I own the three core books and some supplements for that system and happen to like the melieu. I own everything printed for TNE and thus don't see the point switching to anything else, hence no T20,not that I think I'd even like it from what I've read of other peoples posts on it but I'll not judge it.

 

[Todg]

Suddenly the image came to me:

Crews serving CLC lasers. The laser's aren't 100% efficient, and a small bit of each charge becomes heat. Hot, sweaty men, stripped to the waist, with bandanas tight about their heads, serving shells to the guns.

"Starboard side, FIRE!"

I mean, we have cutlasses in Traveller don't we?

"Ensign Jones, ready the space grapples and prepare to board!"

 

[notagoodusername]

You're disturbed...



Shane