• Welcome to the new COTI server. We've moved the Citizens to a new server. Please let us know in the COTI Website issue forum if you find any problems.

Nuke 'em

Carlobrand

SOC-14 1K
Marquis
I've posited elsewhere that the CT High Guard ('80) nuclear missile is a 12-ton yield surface-impact mini-nuke. That's consistent with its effect in that game and with the penetration if it were a Striker weapon facing a ship under those rules. It's not consistent with the HG '80 black globe rules, if you adopt the convention that the EP described represents a full turn's output from whatever weapon is hitting it - and it's hard not to adopt that convention given that the energy absorbed can then be used for jump. If you go there, you end up with a 12 kiloton warhead: those can pretty well vaporize 40% of a Scout/Courier, which is not what happens in that rule set.

Then I thought: "Hey, let's vaporize the scout!" So I did up some very rough guidelines on the use of larger nukes in High Guard.

(We acknowledge that the rule set has some basic limitations that make extrapolation tricky, so one extrapolates with caution and a good degree of unreliability, but it can nonetheless be rewarding sometimes.)

If we assume a standard missile is 12 ton yield, gaining a -6 bonus to the damage roll, then:
  • a 0.1 kt (100 ton) yield warhead gains a -9 bonus (-3 net after the +6 penalty for batteries of Factor 9 or less).
  • a 1 kt yield warhead gains a -12 bonus (-6 net after the +6 penalty for batteries of Factor 9 or less).
  • a 5 kt yield warhead gains a -14 bonus (-8 net after the +6 penalty for batteries of Factor 9 or less).
  • a 10 kt yield warhead gains a -15 bonus (-9 net after the +6 penalty for batteries of Factor 9 or less).
  • a 100 kt yield warhead gains a -18 bonus (-12 net after the +6 penalty for batteries of Factor 9 or less).
  • a 1 Mt yield warhead gains a -21 bonus (-15 net after the +6 penalty for batteries of Factor 9 or less).

This is based off the Striker armor table, which does this curve thing that, past a certain point, ends up very roughly increasing the armor factor by about 8 for each doubling of thickness, and MT's armor-to-bonus calculation, which is a bit easier to work and makes more sense than what Striker offers for translating to space combat armor levels. For example, whether you assume a space combat armor level of 1 is an Striker armor rating of 60 or an MT armor rating of 43, increasing armor (or penetration) by a factor of 10 increases armor rating (or penetration) by 26, which ends up being roughly a +9 to the space combat armor level (or a -9 to the damage roll if it's weapon power being increased). Since the nuke blasts in all directions rather than focusing, I figured the increased penetration as a cube root of the increase in power.

This will in some cases throw rolls off the top of the chart: most or all possible results are a critical when the larger nukes encounter more lightly armored ships. When fiddling with beam weapons, I'd adopted the rule that after all bonuses and penalties including armor are added, the net result can't be less than 0 - basically an unmodified roll - because I figured at some point it's punching through the ship and sending most of the energy out the other side into space. However, for nukes, it seems appropriate for a critical result to occur more often (or all the time) because that unfocused blast is cratering large chunks of a ship like a humongous set of jaws rather than punching through like a lance. So, the bridge disappears in a cloud of incandescent plasma, or the boat bay becomes a glowing crater, or a big bite is taken out of the engine room, and so forth.

As for where to put these warheads, the 12-ton yield warhead seems to be modeled on a real-world warhead, the W54, a nuke designed to be intentionally inefficient to reduce its blast to something an artillery piece could fire without killing the crew. That warhead actually managed 6 Kt in the Hardtack II Socorro full yield test, so I'd boost the turret-launched missile to 5 kt at no added cost if I want nuclear missiles in the game with some real bite.

-8 on the damage roll, and 40% of the scout is indeed getting vaporized - well, 30% - with a missile no bigger than the one already in the game.

Striker thinks the bay-launched missiles are 25 cm and, although MT doesn't agree, the missile bay is flexible enough that one can argue for provisions to launch larger missiles from it. Cost becomes a consideration - bigger warheads cost more - though there is no real consistency on what they actually cost. Cost might be three times as much as the turret missile. Modern era warheads as small as 117-125 kg have delivered 170-200kt (W-58, W62, W-69), so most likely a 100 kt missile would mass around three times the mass and volume of a 5kt turret missile, which makes the bay a good candidate for 100 kt missiles.

Warheads in the megaton range run to 250-300 kg (W56, W59) and would need missiles of more than a half ton or so in mass and a liter in volume if you just scaled up; a single battery-round for a factor-9 battery comes in over 2 dTons. You'd need to give room for ammo storage and keep track of how many you have and how many you'd used, but they'd be deadly, with enough of a punch to completely neutralize Factor-15 armor and give a chance at a crit against even that level of armor. They'd likely cost about ten times as much as the turret missile. At 45 MCr per factor-9 battery-round, with 5 of 6 battery-rounds being stopped by dampers and more stopped by repulsors and such, you're spending a lot to get the hit, but the target's going to really feel that hit. Destroyers will in fact be destroying each other rather than engaging in slap-fights, and SDBs would be a fierce opponent for capital ships (assuming they're no more than a tech level or two below their target).

https://en.wikipedia.org/wiki/Nuclear_weapon_yield

A bit of a hodgepodge mix-and-mash, but it seems to work.

Another interesting idea is to develop a neutron warhead. The warhead would be designed to detonate at a stand-off range to reduce the blast effect on the hull but to deliver an enhanced radiation blast: give it a -5 on the radiation table and no surface damage bonus. The idea would be to eliminate critical and interior results while killing crew and damaging the computers. The weapon would be intended to quickly disable an unarmored target without causing too much damage, giving a warship a better chance to quickly seize a freighter as prize and put a prize crew aboard to make away with it, rather than spending several turns trying to cut down the maneuver drive and weapons enough to allow an opposed boarding. Seems like the kind of thing the Vargr would appreciate.
 
The other nuke rule to look at with CT at least is SS3 Missiles, with nuke warheads that can be anything from +10-100 CT hits, plus a like number of radiation hits.

Even just one 20-hit missile will ruin virtually any ship in the 100-400 range.

Other options are bomb-pumped detlasers, casaba howitzers (effectively a nukedet generated PA stream), and I'm wondering if you could create a plasma/fusion shot from them.
 
The other nuke rule to look at with CT at least is SS3 Missiles, with nuke warheads that can be anything from +10-100 CT hits, plus a like number of radiation hits.

Even just one 20-hit missile will ruin virtually any ship in the 100-400 range.

Other options are bomb-pumped detlasers, casaba howitzers (effectively a nukedet generated PA stream), and I'm wondering if you could create a plasma/fusion shot from them.

That works well in Book 2's small ship universe but it's overpowered for the capital ships, where we have a spinal mount particle beam pulling only a single radiation hit. We'd need to work in some modification to reduce the number of hits based on the target size.

Casaba howitzer, aka nuclear shaped charge, is an interesting idea. My sources are citing only a 10% efficiency in translating the blast to a beam, but that can still be pretty powerful. Potentially makes the missile several times more powerful than that PB spinal, but it's a spear thrust, so I'd treat it like the beam weapons. Range is short for the Traveller setting compared to laser ranges, so they're likely still within range of missile defenses. The BPLs would be able to hit from outside missile defense range, but I'm not sure how efficient they are at converting energy.

http://www.projectrho.com/public_html/rocket/spacegunconvent.php
 
That works well in Book 2's small ship universe but it's overpowered for the capital ships, where we have a spinal mount particle beam pulling only a single radiation hit. We'd need to work in some modification to reduce the number of hits based on the target size.
http://www.projectrho.com/public_html/rocket/spacegunconvent.php
Are you sure about that? I'm pretty sure LBB5 spinal mounts do one damage per roll of each type (surface exp/radiation for particle accelerators) per factor over 9, modified by armour.
 
HG'80 is pretty clear on this:
Spinal Mounts: All spinal mount weapons which hit and penetrate inflict one
extra damage roll (on each appropriate table) for each letter by which their size
exceeds 9
. For example, a particle accelerator with a code of A gets 2 rolls on both
the surface explosion and radiation tables; a factor of B receives 3 rolls, etc.
 
Okay, let's think about this.

HE in that game is pulling multiple hits, but the standard missile as described only mounts enough to produce one, so that's not a problem. FF would produce four for the same quantity, which might be a bit of an issue but we're not looking at those.

Fission warheads come in various yields, 0.1 kiloton to 10 kilotons, but all mass 30 kilograms. That's actually about the right size for those, a bit too big but not too bad. They produce 10 regular hits and 2 radiation hits per 0.1 kiloton of yield per 0.1 kiloton of yield. Base price is sort of in line with the MT price since the smallest one adds Cr100,000 to the missile price, and the inefficiency issue means lower yields would cost the same. On the other hand, the warhead should cost about the same up to 6 kt, but they likely wouldn't have known that. The 12-ton-yield theory puts the missile producing one hit of each - I don't think anyone there thought of that either, but it's a useful coincidence though it leaves us scratching our head on why they'd bother reducing the warhead power.

Fusion warheads are just smaller: 20 kg but same yields and hits per yield, same price except for the triggers at TL8-9.

Enhanced Radiation warheads mass 20 kilograms and come in various yields, 0.1 kiloton to 10 kilotons, producing 8 radiation hits per 0.1 and, on a contact hit, 5 regular hits per 0.1 kiloton. Same price as fission warheads.

Book 2 ships take hits based on letter classification, so while a free trader goes down in one hit, something like a Hercules takes 21 for its 1G, and by extension our giant ships could take hundreds or thousands, where HG gives them at best six. I won't argue the relative merits of basing damage on drive size instead of performance; just noting the two systems are very different there.

Spinal PB produces 2 hits for 500 EP, goes up from there without respect to power. Mesons same. 500 EP is 125 gigajoules, around 30 tons yield. So, starting out at around 2 hit per 30 tons yield, but the big ones end up giving 18 for 60 and 72 tons yield respectively, so 10 hits out of a 0.1 kt nuke is not unrealistic - though they do have the same problems PB spinal have: they don't penetrate any better when they get bigger. I'm working on a variant, but it needs some tweaking still.

Play balance wise, if we penetrate by yield - which seems logical - and then add multiple rolls at 10 per 0.1, we create a system that doesn't need spinals: overwhelm them with missiles. But, a dreadnought should not be taken out by one hit from a 0.1: 200,000 dT, 2.7 million cubic meters, produces something the size of our tallest skyscrapers, covered in armor as strong as 16 meters of steel. PB spinals lose rolls with increased armor; we could do the same here, but subtracting up to 15 doesn't make much of a dent past 0.2 kt, and we could field something as big as a megaton - 10,000 times more powerful than the 10-hit 0.1.

Suppose we start with 1 regular hit from a 0.1 and then go up by the cube root, since we're dealing with a spherical explosion. a 1 kt does 2, a 5 kt does 3 (round down), a 10 kt does 4, a 100 kt does 10, a megaton does about 21 - say 20 for convenience. Appropriately devastating for unarmored ships, but 10 factors of armor - as strong as almost 11 meters thickness of steel - will hold up to anything up to 100 kt (which, with a -12 damage bonus, does penetrate and potentially cause crits but spends most of its energy vaporizing armor to accomplish that).

Radiation, same ratio (2:10) with a minimum of one? So the 100 kt gets 2 and the 1 megaton gets 4. That gives us turret missiles that do 3 regular rolls and 1 radiation roll, bay missiles that do 10 and 2, and megaton missiles that do 20 and 4, which means they'd still pull 5 rolls against a factor F armor, net probability of an interior roll 80% over the 5 rolls.
 
Couple of things.

First - the designers never went into this detail when making their rules, so you are looking for an internal consistency that does not exist.

Next - HG and LBB2 are totally different damage scales, a rule of thumb you can adapt from the K'kree alien module is that 5 LBB2 hits are required to be the equivalent of a HG hit, but take that with a large pinch of salt.

Next - a single crew hit from a radiation strike in HG could incapacitate over a thousand crew, in SS3 it affects one crew member.

Finally - you are wasting your time with nukes since every ship worth anything will carry a nuclear damper and possibly repulsors too. ;)
 
...First - the designers never went into this detail when making their rules, so you are looking for an internal consistency that does not exist. ...

Not really. More like taking one from Column A and one from Column B and seeing where it takes me.

Next - HG and LBB2 are totally different damage scales, a rule of thumb you can adapt from the K'kree alien module is that 5 LBB2 hits are required to be the equivalent of a HG hit, but take that with a large pinch of salt. ...

I haven't read the K'Kree alien module. Not one of my favorite aliens, since they're clear over on the other side of the Empire from my favorite haunts. Thanks for pointing the reference out, I'll give it a read.

...Next - a single crew hit from a radiation strike in HG could incapacitate over a thousand crew, in SS3 it affects one crew member. ...

I thought the errata had rad hits killing sections now. So, for a Plankwell, there'd be 200 sections of six men each.

...Finally - you are wasting your time with nukes since every ship worth anything will carry a nuclear damper and possibly repulsors too. ;)

First, that's only true assuming tech level 15 dampers; at tech level 14, a factor 9 battery only needs a 7 to penetrate. They do pretty much eliminate fighters as a threat, but fighters aren't much of a threat after computers get really big and expensive 'cause it's not cost-effective to field them with effective electronics.

Second, statistics. A factor 9 damper stops 5 out of 6 inbound Factor 9 nuke salvos, but the damper is the last line of defense. You roll lasers and sandcasters first, then repulsors, then the damper. So, instead of your weapons stopping the 16.67% that leak through the damper, your damper is trying to stop everything that got past the beams, casters and repulsors, and 16.67% of those get through. Your defenses can be saturated more effectively.

Say you've got a 200 kt dreadnought with a T meson, so room for up to 193 bays or 1930 hardpoints or some compromise between the two. Say you've taken 100 repulsor bays and the rest you divide among the other secondary weapons as turrets, 'cause you really really want to protect that meson. If the other guy goes mano-a-mano, you can probably stop most or all of what comes at you.

But, he won't. You're part of a fleet: He'll be ganging up on you, 2-3-4 or more ships to 1, and you'll be doing that to him, because you both want to take the other guy's mesons down before they can do too much damage. There'll be a lot of difference of opinion on the best balance of weapons but the one truth is that, in a fleet battle, you are absolutely going to get hit by nukes. Probably a lot of them. Your agility will keep some at bay, your weapons will knock some down, your screens will stop some - but he will be trying to calculate the right number to send over to get through all that and whittle down your weapons. You will absolutely get hit, and you will get hit as hard as he can manage until he's satisfied that he's reduced the threat from you enough, and the rest of your fleet will be pretty much ignored. There's no point in him taking on ALL of your fleet's repulsors and beams and such when he can overwhelm you at one point while leaving the rest of the defenses to sit idle waiting for their turn under the guns. And you'll be doing the same to him.

And, missiles are pretty cheap; I think they're overpriced, but I'm mainly jaded by Striker's bargain basement pricing. A factor 9 battery-round of 30 canon nukes is MCr 4.5, maybe a bit less if you price them off SS3 instead. A dreadnought comes in around MCr 120,000 to 150,000 or so. Call it about 30,000 battery-rounds to the ship. 21/36 fall to maximized agility, 30/36 fall to dampers, but he only needs to hit you enough to make it worth the price - which is to say to shave your T down enough, with fewer than 30,000 battery-rounds, that one of HIS dreadnoughts can leave the battle intact rather than having to be replaced, thereby making up the price of the barrage.

The real problem is: unless the opposing fleets are pretty big, having maybe 2 or 3 missiles out of a hundred hit doesn't affect the outcome; mesons decide the battle too quickly. Your ships go boom, his ships go boom, and four or five turns of booms later the battle's decided before the missiles can have an affect, rendering the missile barrages both moot and a waste of money. Armor only makes that worse. Better to field more mesons than to bother with missiles.

However, if you alter the damage outcome enough, then missiles can pay for themselves by eliminating one threat before it has time to take out an opposing ship. And the big ones - one hit out of a hundred or two hundred battery-rounds can be meaningful if that one hit takes an opposing ship out of the fight.

Also helps to revamp the meson rules to make them less deadly, but that's a separate project.
 
ToughSF presents numbers on a casaba howitzer, which they're calling a nuclear lance.

http://toughsf.blogspot.com/2016/06/the-nuclear-spear-casaba-howitzer.html

Small Casaba Howitzer (50kg)
0.01 radian directivity (0.057 degrees)
5kt yield, 10% efficiency: 2.09TJ
Distance 1km: Irradiance = 2.09GJ/m^2
Distance 10km: Irradiance = 209MJ/m^2
Distance 100km: Irradiance = 2.09MJ/m^2
Distance 1000km: Irradiance = 2kJ/m^2

That's something that would fit on a missile the bay could launch. 2.09GJ/m^2 is enough to vaporize iron to a depth of 4 cm, which isn't of much use against our flying tanks. The angle is what was achieved experimentally, according to the site, so maybe we can assume a better angle. Getting it to 0.001 radians would put out enough focused power to get through 4 meters, which is about double what it can do in a contact detonation. Takes the bonus from -14 to -22 (net -16 after the +6 penalty for batteries of Factor 9 or less), which is very nice for a turret-launched missile.

As I said earlier, I had the rule for spearing-time weapons that after all bonuses and penalties including armor are added, the net result can't be less than 0 - basically an unmodified roll - because at some point it's punching through the ship and sending most of the energy out the other side into space, while the blasting weapons get the full benefit of their bonuses. I'm not sure why it would be a benefit to detonate from one km off. The sites were assuming thin hulls and missiles detonating from outside the range of defensive weapons. Maybe we give a bonus to hit for aiming and firing what amounts to a beam weapon from a klick off? A little risky in a missile with this much punch, but it seems logical.
 
Back
Top