Traveller Nuke Yield?

[Sepulchrave]

For the sake of simplicity, I've always assumed that nukes fired from turrets have yield in the 0.1 to 1Kt range and that bay missiles (I use a torpedo-type bay missile) has a yield of 10Kt+.

Does anyone have any other ideas? What seems reasonable?

 

[far-trader]

FWIW the CT "Special Supplement 3: Missiles" lists the warhead component (of the standard 50kg missile) as 30kg for a nuke with varying yields available from 0.1Kt to 10Kt yield

In MTU that would put the torpedo version (3 times the missile size) at a 90kg nuke warhead with up to 30Kt yield, though I'm not at all sure it scales linearly.

 

[far-trader]

Further, a quick google shows the theoretical maximum yield (for thermonuclear fusion warheads) is about 6Mt / metric ton. Practical yields are lower. The best yet achieved (and probably close to the maximum possible) was 5.2Mt / metric ton.

The standard 30kg warhead above could be as much as 1000Kt (in round numbers) if I didn't mess up the math. Considerably more than the 10Kt stated. Though the small size would reduce the yield considerably. At a guess I'd say the stated 10Kt is good, and my TU torpedoes would top out at 100Kt (so more a factor of 10 bigger bang rather than just linear). I like it.

 

[McPerth]

As I've seen this question in several threads already, let me givve you a resume of the calculations I've done, based on the energy absorbtion of the Black Globe capatiors:

In the Black Globe section of combat rules, it’s specified that nuclear missiles inflict 25000 Mw per factohat means a TL 7-12 single missile inflicts 25000 Mw, and one TL 13-20 inflicts 50000 Mw. As Mw are power and we are talking about energy released, and assuming the black globe rules are in Mw turn, they should inflict about 8333 (TL 12-) or 16666 (TL13+) mw hour.-

1 w = 1 joule/second

So, 1 wat hour= 3600 joules

1 kton= 4.184 x 10^12 joules = 1.16222 x 10^9 wat hour=1162 Mw/hour

That puts the TL 12- missile at the 7 kton range, and the TL 13+ on the 14 kton range.

This is calculated in MT numbers, but HG numbers (keeping the 1ep=250 Mw given in several sources) give more or les the same results.

In MT there are no differences among turet and bay missiles, just bays launch more of them . In HG, AFAIK, the missiles themselves are not talked about (no volume nor price is given), so it's difficult to know if bays launch larger missiles or just more of them.

 

[aramis]

Further, a quick google shows the theoretical maximum yield (for thermonuclear fusion warheads) is about 6Mt / metric ton. Practical yields are lower. The best yet achieved (and probably close to the maximum possible) was 5.2Mt / metric ton.

The standard 30kg warhead above could be as much as 1000Kt (in round numbers) if I didn't mess up the math. Considerably more than the 10Kt stated. Though the small size would reduce the yield considerably. At a guess I'd say the stated 10Kt is good, and my TU torpedoes would top out at 100Kt (so more a factor of 10 bigger bang rather than just linear). I like it.

At 30 kg, that's 0.03 Tons, x5200KT, 15600/100=156Kt

 

[stealth]

Well...

If they work like modern nukes, look at the W-88. It weighs less than 800 lbs and has a yield up to 475 Kt (it's a "dial-a-bomb" variable yield device).

Now that's a boosted fission/fusion device with a uranium core and a pebble of PU too, so it uses a fission reaction to start a fusion reaction. At TL-13+, fusion is achieved "by other means" says the rules.

So that means about 1Kt yield per kg of missle warhead before TL 13.

 

[far-trader]

Thanks for the math check Wil. I was pretty sure I'd messed up the decimal

 

[Xerxeskingofking]

it would be worth noting that "maxium possible yield" is not the same as "maxium desireable yield", while it my be possible to make a stupidly large warhead that fits into a traveller missle hull, it may not be desired, for several reasons, such as cost, stability of warhead, effects of dentonation on your own targeting systems (i.e. being blinded by your own nukes), feasability of large scale manufacture*, or any of a dozen reasons not covered by the rules.

*we are talking about having to supply billions of warheads to supply the Imperial Navy. I don't have my copy of the MgT Fighting Ships book, but i think the Tigress had a missle magazine capacity in the hundreds of thousands. the MgT High Guard example 200Kt battleship takes 32,000 missles, and 12,000 torpedos as well.

(for referance, the MgT Missle bays fire 12 or 24 standard missles for the 50 and 100 ton versions)

 

[far-trader]

it would be worth noting that "maxium possible yield" is not the same as "maxium desireable yield"...

Absolutely. Cost being a big one imo, especially for smaller ships. Of course I don't think a single canon design in CT Supp 7 has allocated proper volume (or expense consideration) to missile stores. They seem to have some sort of magic missile fabber aboard

Also I think the idea in CT (Special Supp 3) was that you would purchase your desired yield warhead (0.1Kton to 10Kton) at variable cost and for specific application. Not that it was a dial-a-yield warhead (though possible).

 

[HiverLord]

it would be worth noting that "maxium possible yield" is not the same as "maxium desireable yield", while it my be possible to make a stupidly large warhead that fits into a traveller missle hull, it may not be desired, for several reasons, such as cost, stability of warhead, effects of dentonation on your own targeting systems (i.e. being blinded by your own nukes...)

This probably belongs in another post, but...
This thread reminded me of an old run in the mid-80's. The pilot of a free trader-type vessel made the mistake of launching a nuke... just over a hill on the horizon... missed and hit the hill... while he was wearing IR Goggles...

Oops. :devil:

It was one of those 'hot' actions, and he forgot to take them off when returning to the ship. I gave him a roll to see if he remembered to take them off. He failed miserably, of course.
I was 'nice' to him, and only put him out of action for 6 months, so he could get back to civilization and have some new eyes grown for him...
Ah, memories! :rofl:

 

[Sepulchrave]

Thanks, all, for swift responses. It seems I'm in approximately the right / shared ballpark - at least within a factor of 10.

I guess another question or two: in atmosphere, around half of the energy of a nuclear explosion is contained in the blast/shockwave. What happens in space? More thermal radiation? More gamma rays?

Is it reasonable to assume that a 'hit' with a nuclear weapon might, in fact, be 'somewhere nearby?' It seems that a 1Kt explosion 200m away from your ship is going to hurt.

 

[Icosahedron]

... while he was wearing IR Goggles...

I was 'nice' to him, and only put him out of action for 6 months, so he could get back to civilization and have some new eyes grown for him...
Ah, memories! :rofl:

Hmm. Don't try that with my character... My guess is that he would be much better off wearing goggles than not. Without them, enough IR radiation would burn his retinas, but with them, the IR would simply white-out the goggles, and staring at a white screen for a few (milli?)seconds (before it blacked out from crisped photo-receptors) is unlikely to do his eyes permanent damage.

I guess another question or two: in atmosphere, around half of the energy of a nuclear explosion is contained in the blast/shockwave. What happens in space? More thermal radiation? More gamma rays?

Is it reasonable to assume that a 'hit' with a nuclear weapon might, in fact, be 'somewhere nearby?' It seems that a 1Kt explosion 200m away from your ship is going to hurt.

I'm no expert, but as a logical analysis:
The yield determines the energy output - you get the same energy no matter where it's detonated. The gamma output is not significantly affected by atmosphere, so you wouldn't notice much difference there, but in an atmosphere, much of the thermal output is absorbed by the nearby air and transformed into kinetic energy of the air molecules - creating an expansion of gas and the pressure wave we call an 'explosion'.
In space, the thermal energy would not be absorbed, so it would feel hotter at greater range - targets would melt rather than smash. At a range of 200m, I'm not sure the warhead shrapnel/vapour would do much damage to a ship, but the thermal radiation might raise the facing side of the hull above its melting point, and the gamma might fry the crew,

In space no-one can feel you explode...

This is why firing nukes at a 'doomsday asteroid' is unlikely to divert it. The only 'impact' you have is a few kg of fast-moving warhead material.

Now a kinetic penetrator nuke that detonated inside a ship would do some damage... :devil:

 

[HiverLord]

Hmm. Don't try that with my character... My guess is that he would be much better off wearing goggles than not. Without them, enough IR radiation would burn his retinas, but with them, the IR would simply white-out the goggles, and staring at a white screen for a few (milli?)seconds (before it blacked out from crisped photo-receptors) is unlikely to do his eyes permanent damage.

What can I say? It was the 80's, didn't know nearly as much about tech at the time (probably still don't, for that matter), and it was fun to torment my buddy for making an obvious mistake.

 

[BytePro]

30 or 50 kg - is that the missile, the warhead, or the mass of the 'active ingredient'? What is the core material? What configuration efficiency is assumed? Those facts make all the difference in the world and don't have to relate to the RW in a SciFi setting.

Also, how old is it - if its a fission weapon, then there is a half-life. In the RW, material must be routinely replaced every so many years to assure effectiveness for a given CM. (Hehe - have fun with your players with this one - there was a reason they got such a low price on that last load-out of missiles... :devil

But I already know exactly how powerful a weapon yield it has - it is enough to damage a starship.

BTW: An explosion in space generally yields the same amount of energy* but in a much greater volume. In outer space there is the benefit of very little matter to absorb output*, but the disadvantage of dispersing it over a much greater volume without the advantage of material to transfer it. Thus, typically greater range, but generally less damaging per unit area. Everything is situational - there is not one simple answer - but, generally, explosions in space are less 'damaging' overall.

(*I will not attempt to use 'proper' physics terminology - it confuses way too many people.)

 

[far-trader]

30 or 50 kg - is that the missile, the warhead, or...

Well, for CT the 50kg is the total missile mass/volume while the 30kg is the minimum nuclear warhead package available per Special Supplement 3 (I guess smaller nukes were not considered powerful enough to damage a ship at space combat ranges).

As for other specifics, yeah the game mostly glosses them over to arrive at...

But I already know exactly how powerful a weapon yield it has - it is enough to damage a starship.

 

[BytePro]

I'm a fairly (ok, overly) technical person in RL - but in games I like glossy. Less is more in this case, as less details = more believable. Gloss is harder to punch holes in than made up tensile strength and the like.

One can still be 'technical' without using RW units and materials. For instance, a weapon yield against spaceships would naturally be related by an armour piercing or effectiveness 'factor'. Equivalent tons of TNT is actually meaningless unless the weapon detonates under specific conditions (like inside an enclosed space with a given atmo, etc.), the effectiveness will vary. And weapon effectiveness is what really matters when talking about yield.

In the RW this type of thing is done all the time. Ratings, classes, scales - these are all qualitative measures related to qualitative effects that allow useful comparisons.

 

[stealth]

Hmmm...

A regular missle actually has to hit it's target, so let's assume nukes do the same, since they have the same hit chance.

 

[BytePro]

Does it? Why can't it's warhead have a proximity detonation?

A warhead that depends on a very specific sequence of physical events to occur may not necessarily work on impact, but must rely on initiation immediately prior to its own destruction. If exterior to armour, and in space, the effectiveness can be drastically reduced. Against armour, many weapons would implement penetrator technologies.

Planetside warheads can actually be more effective when air-burst... depends on the nature of the target and the objective.

 

[sabredog]

In Striker a TL-15 30cm nuclear warhead yields 50kt. Seems low to me given the advances made lately but then Traveller is full of anachronisms like that. On the other hand 50kt going off in a contact (or near contact) detonation is sure going to mess up a ship.

Proximity effectiveness in vacuum is different than in atmosphere: in the atmosphere the explosive power is multiplied by the shockwave from the compressed air expanding away from the explosion - then from the air rushing back towards ground zero to fill the vacuum created by the fireball and explosion. An airburst multiplies that effect since all the force expands equally around the center of the explosion instead of some being forced into the ground (which has its advantages, too).

In space their won't be any shock wave effect, but there will be impact from the particle and radiation. So a proximity detonator wouldn't be very effective depending on how far away the warhead detonated. A nuclear weapon built for it could even have am induced radiation warhead for increased crew and electronics casualties.

But a warhead that had a penetrator warhead that punched into the armor and then detonated the nuke would be especially devastating. And a contact detonation would scoop out huger sections of vaporized armor and components.

 

[sabredog]

A regular missle actually has to hit it's target, so let's assume nukes do the same, since they have the same hit chance.

Yes and no: depending on how you design missiles in your game they can have several different kinds of seekers and detonation systems. According to CT the standard missile described in the rules is a fire-and-forget homing missile that has a proximity detonator and HE warhead. Probably similar to the modern AAM's that have a warhead wrapped in wire or rods that spin off and damage the target like a shotgun round.