Tac-nukes vs. Nuclear Warheads

[CorPse]

Well,

 

Wasn't sure where to put this one, but here goes.

 

Anybody have a sense of how to model tactical nuclear weapons (nuclear tipped missiles that fighters might carry, howitzer rounds, etc.) verses the kind of warheads you find on ICBMs?

 

Is the damage the same, but with a larger area for ICBMs? Or is it matter of more megatons equal a much bigger blast.

 

The books I've got seem to show an ICMB topping out at a 20d6 RKA with lots of other special effects.

 

Thoughts? Suggestions?

 

I'll take my answers in the morning...

[Inu]

Re: Tac-nukes vs. Nuclear Warheads

 

ICBMs also tend to launch multiple warheads, not just one.

[Sundog]

Re: Tac-nukes vs. Nuclear Warheads

 

There's a qualitative as well as quantitative difference.

 

Most tactical level devices are pure fission or deuterium-enhanced fission; they're not much worse than the effects we can get with modern conventional munitions, such as Daisy-Cutter Fuel-Air Explosives (in fact, this is one reason Daisy-Cutters are used sparingly - they can be confused with a low-yield nuke).

 

 

Strategic devices, whether single-warhead, multiple warhead or true MIRV (Multiple Independent Reentry Vehicles - individual warheads that each have a separate target and home individually) are usually fusion weapons. That gives between five and ten times the yield of a same-size fission device.

 

20d6 Armour Piercing, Penetrating, Explosive, reduced dropoff (1 dice per five hexes) is what I'd use for a Tactical weapon - while small, they are astonishingly lethal, and nothing but the most powerful supers should be able to survive being close to one.

 

For a small Strategic weapon, make it more like 30d6, double armour piercing, penetrating, explosion megascale 1KM for a 1 megaton device; scale up according to the megatonnage. Note that with multiple-warhead devices, they're designed to detonate in a radius around the actual target, massively enhancing the footprint.

[Captain Obvious]

Re: Tac-nukes vs. Nuclear Warheads

 

I think the 20d6 version is supposed to be a 1 Mton weapon. For a tac-nuke you'd scale down from there. I don't have any references in front of me at the moment, but I believe tac-nukes run about half a kton, so that would be about, what, 11 halvings? Working with the standard Hero explosives scheme, that would be a drop of 22 damage classes, for a total of about 12 1/2 d6 RKA, with other effects scaling down similarly.

[Edsel]

Re: Tac-nukes vs. Nuclear Warheads

 

If you can find a copy of the Hero System Almanac 2 (printed in 1995), there is a six page long article by Steve Long that details the effects of Nuclear Weapons. It includes an exhaustive write-up of the effects of a 1 megaton bomb. You could scale that data down a bit for less powerful tactical nuclear weapons.

 

In summary this version of nuclear weapons gives them eight effects in a single attack.

1. A radiation burst which is an RKA AVLD vs. Power Defense.
   
2. The flash of light which is actually a Major Transform to make observers blind.
   
3. A thermal blast which is simply a powerful heat RKA.
   
4. An EMP attack which is a RKA that only targets electronics.
   
5. The blast wave of static overpressure, another big RKA.
   
6. A follow-up negative pressure wave of the air rushing back into the void. Another RKA but not as powerful.
   
7. The firestorm effect which is an Aid to all existing fires in the area.
   
8. The Radiation fallout / Nuclear Winter effect. This is left rather vague but it is suggested that it be modeled with a large area Change Environment of some sort.
   

[Evil Steve]

Re: Tac-nukes vs. Nuclear Warheads

 

Edsel is right, the Hero System Almanac II has rules for nukes, but they're pre-Megascale, so the costs are much higher than under current rules.

 

Step 8 in the above effects may not be appropriate for tac-nukes, as it would result from a more traditional exchange of nuclear gifts.

 

Long ago, I posted a similar question on the Townhall forums (long long ago) and was wisely informed that nukes do whatever the heck they want-they're nukes. If the gm says you die-you die.

[Kristopher]

Re: Tac-nukes vs. Nuclear Warheads

 

Edsel is right, the Hero System Almanac II has rules for nukes, but they're pre-Megascale, so the costs are much higher than under current rules.

 

Step 8 in the above effects may not be appropriate for tac-nukes, as it would result from a more traditional exchange of nuclear gifts.

 

Long ago, I posted a similar question on the Townhall forums (long long ago) and was wisely informed that nukes do whatever the heck they want-they're nukes. If the gm says you die-you die.

 

They should be of the far more expensive version. Megascale was a bad addition to the game.

[CorPse]

Re: Tac-nukes vs. Nuclear Warheads

 

Long ago, I posted a similar question on the Townhall forums (long long ago) and was wisely informed that nukes do whatever the heck they want-they're nukes. If the gm says you die-you die.

 

Good point, but I'm working up some stuff for an Ogre conversion and standard ammo appears to be tac nuke shells... I'm just trying to figure out where to go in terms of Damage and DEF before I start working out other mechanics.

[robertep]

Re: Tac-nukes vs. Nuclear Warheads

 

well once you get over to my house I can let you look at the HEROglyphics I I have where Steve go on about Nuclear weapons and such.

[Outsider]

Re: Tac-nukes vs. Nuclear Warheads

 

Good point' date=' but I'm working up some stuff for an Ogre conversion and standard ammo appears to be tac nuke shells... I'm just trying to figure out where to go in terms of Damage and DEF before I start working out other mechanics.[/quote']

 

Whew!

[CorPse]

Re: Tac-nukes vs. Nuclear Warheads

 

well once you get over to my house I can let you look at the HEROglyphics I I have where Steve go on about Nuclear weapons and such.

 

Definitely, sounds cool.

 

Probably coming over after 2pm...

 

cP

[CorPse]

Re: Tac-nukes vs. Nuclear Warheads

 

Whew!

 

Don't worry... nothing that will ever appear in the UNTIL game!

[Comic]

Re: Tac-nukes vs. Nuclear Warheads

 

Tac Nuke can mean anything, though, can't it?

 

In a game where Mad Science can create 250 point characters with 'Nuclear' special effects that do 8d6 damage, that could be a 'Tac Nuke Blast'.

 

I've long since forgotten what the power of the theoretical minimum reliable fission explosion would be. I know there is one, but I leave such details to the sciency folks.

[shadowcat1313]

Re: Tac-nukes vs. Nuclear Warheads

 

in Traveller nukes are more common in space combat than on the ground, and there are dampers to mitigate a lot of that damage. whats more common are the Detonation Laser Nukes

 

which give you a 1 shot graser at standoff range.

 

12D6AP usually

 

Honor Harrington nukes would be about the same but an AOE or Autofire

[CorPse]

Re: Tac-nukes vs. Nuclear Warheads

 

in Traveller nukes are more common in space combat than on the ground, and there are dampers to mitigate a lot of that damage. whats more common are the Detonation Laser Nukes

 

which give you a 1 shot graser at standoff range.

 

12D6AP usually

 

12d6 AP RKA?

 

(That would be my guess, anyway.)

[shadowcat1313]

Re: Tac-nukes vs. Nuclear Warheads

 

nah... its stun only

 

for when you want to "Set Phasers on Tickle"

 

just standard rka

[CorPse]

Re: Tac-nukes vs. Nuclear Warheads

 

nah... its stun only

 

for when you want to "Set Phasers on Tickle"

 

 

Dude, I'm just gonna take it then.

[Old Man]

Re: Tac-nukes vs. Nuclear Warheads

 

Note that, in real life, the damage mechanism varies according to yield. For very small yields, up to around 3 kt, most damage (to people) is the immediate radiation burst (as distinct from fallout). From there up to maybe 250kt the main damage mechanism is blast. Higher yields than that cause damage mainly from heat; a 20 MT warhead will probably combust everything flammable, and inflict 3rd degree burns, within about 15 miles (assuming a nominal airburst).

 

Of course every warhead will give off blast, heat, prompt radiation, and fallout, but what changes is which effect is most powerful at the periphery of the effect. Obviously a very large warhead gives off more prompt radiation than a suitcase nuke, it's just that the heat is killing you further out than the radiation is.

[RJB]

Re: Tac-nukes vs. Nuclear Warheads

 

Hi guys! Former CBR Spec here. I think you call it NBC these days. Let me give you a simple, practical formula for determing damage and range.

 

First, Range: The rule is that 10x the yield = double the radius. So if the Hiroshima blast (12.5KT) had a radius of 3.5 miles, then 125KT = 7miles, 1.25MT = 14miles and so on.

 

Next, Damage: As nukes are measured in tons of TNT, lets go to pg72 of Golden Age Champions. One pound of TNT is listed as doing 8d6, with each double of weight adding +2d6. From this we can extrapolate that your average suitcase-sized tactical nuke (say 1.25KT) would do 50d6 over a range of 1.75miles (1400"). The range multiple would be -1d6/28".

 

A Hiroshima sized bomb would be 57d6(aprox) over an area of 2800" so the mutiple should be -1d6/49"

 

A typical fusion device (lets make it 12.5MT just to save me the headache) would do 77d6 over 22400" which is -1d6/291"

 

As for the bomb effects, these can be dealt with in very simple terms. The first thing that happens is the flash which crispy fries you. Assuming you're still alive, the next thing that happens is the air, superheated from the fireball and expanding at supersonic speed, blasts you to bits. This is easily recreated by simply assuming that the d6 damage is a heat explosion and the wind is double knockback.

 

So how would it all work? Let's presume some nut explodes his suitcase bomb in a city. How would it affect an armored wall at ground zero, an armored car a half mile away, and Joe Normal one mile away.

 

The Wall: With a 13Def and 7Bod it is totally vaporized along with anything on the other side of that wall. Nothing but shadows, folks.

 

The Armored Car: At 400" distance, the blast would lose 14d6. As 8 of these dice are likely to be 6s, the remainder is likely to add up to 30Bod. As the Armored Car has 8Def and 18Bod, this means it's still melted, along with anyone/anything inside. If you want to allow that the vehicle isn't totally destroyed until it's lost twice its body, then the knockback (60-7avg=53") will likely do another 26d6 damage to it. This will be enough to leave the car scattered all over the road.

 

Joe Normal: At 800", Joe takes a paltry 22d6. 8 of these dice are likely to be 1s, so Joe is likely to be hit by a 14Bod blast (Notice I'm not bothering with stun here?). Joe has a 2ED and 10Bod so the blast leaves him at negative 2Bod. The knockback (28-7avg=15") does another 7d6 to him and reduces his body to -7. Amazingly, Joe could live through this if he gets immediate medical attention.

 

Hope you find this useful.

 

BTW: Let's do a neutron bomb too. A neutron bomb is a fusion bomb with it's outer packet of plutonium removed, so there's no fusion. The practical result is that you get a 1KT size physical explosion, while the area that normally would be affected by a 10KT explosion gets turned into an outdoor microwave oven. Nothing protects from this, not even tank amor, which is why the Soviets were so pissed about it back during Reagan's 'Evil Empire' days. In game terms, it would look like:

 

50d6ex -1/28" if non-organic. If organic, then it's 50d6 -1/56" NND. Just roll the dice once and remove as many dice as needed for each target. No extra knockback for organic targets.

 

In the case of the above examples (wall, car and Joe), the wall and car take exactly the same damage and knockback. Joe takes 28Bod and is fried.

 

Were all three objects each 2 miles away from the blast, the wall and car would be completely unaffected, but Joe would still take 13Bod.

[Vestnik]

Re: Tac-nukes vs. Nuclear Warheads

 

Poor, poor Joe.

[Tom Carman]

Re: Tac-nukes vs. Nuclear Warheads

 

BTW: Let's do a neutron bomb too. A neutron bomb is a fusion bomb with it's outer packet of plutonium removed' date=' so there's no fusion.[/quote']

 

???

 

My understanding was that a thermonuke runs fission-fusion-fisson: trigger to main bomb to plutonium blanket. The neutron pulse from the fusion reaction is largely used up fissioning the outer plutonium without it needing to be first compressed to critical mass. Or do I have that wrong?

[Doc]

Re: Tac-nukes vs. Nuclear Warheads

 

???

 

My understanding was that a thermonuke runs fission-fusion-fisson: trigger to main bomb to plutonium blanket. The neutron pulse from the fusion reaction is largely used up fissioning the outer plutonium without it needing to be first compressed to critical mass. Or do I have that wrong?

 

Onsy in the soviet designed 'Tsar Bomba'. It is the only fission-fusion-fission system with a yield of 100MT... It as never been tested to its full yield (ie, with the last fission) because the amount offallouts would have been awfull and would have represented a threat over a too large territory.

 

http://en.wikipedia.org/wiki/Tsar_bomba

 

As for the rest of the discussion, it is now very unusual that nuclear warheads have yields over 1MT, and those are pretty rare. The reason is that with MIRVs, it is easier to hit a single target with more than one medium yield warhead (generally, about 500KT). This enables far more devastating damages to the target (generally, a fortified military installation, as civilian installation only need one shot to be destroyed, wich is not the case for, let's say, underground missile silos or a crisis headquarter...). Today, only China, I think, still keeps an arsenal of 4MT warheads, mainly because they just don't invest in newer and smaller heads and launchers (why, after all, invest to be 'more' able to destroye the world?). These technologies date from the 60s.

 

The main difference between tactical and strategic nukes is their use. Tacticals only serve against troop concentrations or 'big' targets, such as tank or infantry divisions in the open or a carrier. Strategics target hole cities, but 200KT are far enough to destroye every thing in an urban center. France and UK have arsenals of 200KT warheads.

 

Well, sorry about this; I have a kind of morbid fixation on those global suicide things (too much 80s japanese animes in my tender youth...)

 

http://www.atomicarchive.com/Effects/index.shtml

http://www.princeton.edu/~globsec/publications/effects/effects.shtml

http://www.fas.org/main/content.jsp?formAction=297&contentId=367

http://meyerweb.com/eric/tools/gmap/hydesim.html

[Captain Obvious]

Re: Tac-nukes vs. Nuclear Warheads

 

The Soviets went with larger warheads, on the whole, because their targeting systems weren't as accurate. You can miss by a wider margin if your area of effect is bigger. I imagine that probably explains China's 4Mton weapons too, more than economy. It's not China's way to accept second or third best if #1 is in their reach.

[Doc]

Re: Tac-nukes vs. Nuclear Warheads

 

The Soviets went with larger warheads' date=' on the whole, because their targeting systems weren't as accurate. You can miss by a wider margin if your area of effect is bigger. I imagine that probably explains China's 4Mton weapons too, more than economy. It's not China's way to accept second or third best if #1 is in their reach.[/quote']

 

 

Sure, but China trully has a different approach to its nuclear arsenal than the other nuclear power. For instance, it's the only nuclear power to have a public engagement not to hit first when it commes to nukes. It is also the only nuclear power to have an engagement not to target nor to threaten by nukes a non nuleear power.

 

You're probably right about China's targetting precision, but I beleive it would be soon outdated if their government wanted to, as it sent a rocket to the moon last month and the chinese space program is only at its beginning. Moreover, China has only 20 long range ICBM able to strike at the US. Why build more? China's nuclear strategy is only a deterrence one. In case of a war between the US and China, could the government of the US afford to lose even one city like New-York? 20 4MT is all the chinese government needs to further its nuclear strategy.

 

(We can talk about so much things in a RPG forum...!)

[Captain Obvious]

Re: Tac-nukes vs. Nuclear Warheads

 

Sure' date=' but China trully has a different approach to its nuclear arsenal than the other nuclear power. For instance, it's the only nuclear power to have a public engagement not to hit first when it commes to nukes. [/quote']

 

Where do you get that? The official position of the US is "no first use". That might be a open to a little fudging, as in the US might use a nuke against a country that launched a large-scale chemical attack, but I highly doubt China would sit back and take that either.