Spaceships: Missile launchers and their individual mass

[Ulzgoroth]

Originally Posted by vicky_molokh

A 'slugfest' of missiles between broadsiding titans, or a situation where missile lock-ons are relatively rare (maybe up to a dozen per combat at most), nasty if they hit, and result in a pilot spending quite some while and effort on evasive manoeuvres in order to avoid destruction, are almost impossible to implement using standard rules.

You might be able to make the slugfest of titans work if your ships have enough HP compared to the missile hit. If you used large ships with the Spaceships 3 Damage Reduction option and something to rule out nuclear weapons (Nuclear Damper fields, for instance), you might be able to make it happen. I haven't looked closely at the numbers, but missile damage grows slower than ship HP so big ships have better ability to tolerate hits.

The latter is supportable to a degree too. If you have small fighters they have relatively little space to carry huge missile volleys. Each 16cm tube is a Major Battery at SM +4. For good pilots on ships with a decent maneuver rating, dodging can be an important part of the defense, and evasive maneuvering gives a precious bonus to that. If you use reactionless drives on ships to limit the effective range of missiles, it might even make sense to design small craft with combined missile and non-missile armaments. Maybe.

[vierasmarius]

Originally Posted by Ulzgoroth

I haven't looked closely at the numbers, but missile damage grows slower than ship HP so big ships have better ability to tolerate hits.

Yeah, projectile damage and beam damage follow completely different scales. Beams increase in damage at the same rate as HP (so a Major Battery typically inflicts damage equal to 70% of the firing ship's HP). Missile damage starts out high, but doesn't increase as rapidly - an SM +5 Major Battery inflicts roughly x5 the firing ship's HP, while an SM +15 Battery inflicts about 60%. However, this just means that full-sized missiles are practically never used, instead swarming the target with as many small-sized missiles as possible. And of course, if nuclear warheads are available they will almost certainly be used instead - a 16cm missile can carry a 25kt warhead at TL7, giving almost x2.5 damage for a proximity blast, and instant death for all but the largest targets on a direct hit.

While the calibre/velocity-based damage for projectiles may be realistic, it doesn't match the "reality" seen in many science fiction stories (especially space opera). I've toyed with changing the scaling of projectile damage to roughly match the progression of beams, but haven't really come up with numbers I'm satisfied with.

[Ulzgoroth]

Originally Posted by vierasmarius

Yeah, projectile damage and beam damage follow completely different scales. Beams increase in damage at the same rate as HP (so a Major Battery typically inflicts damage equal to 70% of the firing ship's HP). Missile damage starts out high, but doesn't increase as rapidly - an SM +5 Major Battery inflicts roughly x5 the firing ship's HP, while an SM +15 Battery inflicts about 60%. However, this just means that full-sized missiles are practically never used, instead swarming the target with as many small-sized missiles as possible. And of course, if nuclear warheads are available they will almost certainly be used instead - a 16cm missile can carry a 25kt warhead at TL7, giving almost x2.5 damage for a proximity blast, and instant death for all but the largest targets on a direct hit.

The desire to swarm with small missiles can be countered in a couple ways.
-Lots of armor: leviathans can carry enough protection to actually stop small-caliber missile hits outright. Armor improves on the same scale as HP.
-If you enforce the tertiary battery minimum large ships won't be able to throw huge clouds of 16cm missiles, though you have to watch out for small craft, and the point defense advantage of small escort craft is a bit weird.

You've definitely got to do something about the nukes, though. 25kt warheads are, as you say, overwhelming. And very affordable, if you can afford missiles at all.

Originally Posted by vierasmarius

While the calibre/velocity-based damage for projectiles may be realistic, it doesn't match the "reality" seen in many science fiction stories (especially space opera). I've toyed with changing the scaling of projectile damage to roughly match the progression of beams, but haven't really come up with numbers I'm satisfied with.

For a really space-operatic treatment that doesn't leave basic mechanics for dead in an alley, you'd probably need to justify missiles with warheads rather than kinetic munitions. Pseudovelocity missiles maybe? Or in Star Wars-level stuff acknowledging that space speeds are substantially under 0.5 mps.

[roguebfl]

Originally Posted by mearrin69

We never see inside a ST ship's torpedo bay in any show but I'd say this machinery looks plausible...

Actully we did see the inside of the one Torpedo Bays of the NX-01 the 'Armory' was part Torpedo Bay, we even saw the torpedos load a few times in combat when Lt. Reed was working from there instead of the Bridge.

[ericbsmith]

Originally Posted by roguebfl

Actully we did see the inside of the one Torpedo Bays of the NX-01 the 'Armory' was part Torpedo Bay, we even saw the torpedos load a few times in combat when Lt. Reed was working from there instead of the Bridge.

In Star Trek 2 they load Spock's body into a Torpedo Tube and fire it; the funeral scene just before it take place in the Torpedo Bay. There were several scenes in the Torpedo Bay prior to the funeral as well. In the big battle at the end of Star Trek 6 Spock performs surgery on a Torpedo while it's on the loading track then loads it into a tube to fire. In the Next Generation episode In Theory Data begins to court a crewwoman who apparently is a Torpedo Bay operator, as several of the scenes take place in the Torpedo Bay. OK, I had to look the last one up, but remembers the other two

[vierasmarius]

Something to consider in regards to nuclear warheads is the "Taming Explosions" damage option in Pyramid 3/34. This changes large explosives (above 100lb TNT equivalent) to use cube root of weight instead of square root, so they scale better with the HP of large vehicles. This drops the 25kt warhead from dDam 4d x 1000 (in vacuum) to around dDam 4d x 140. Not sure if a proximity blast should remain at 1/100 damage; if so, a 16cm nuke is far less scary, inflicting only about 20 dDam from a proximity detonation.

[Fred Brackin]

Originally Posted by Ulzgoroth

For a really space-operatic treatment that doesn't leave basic mechanics for dead in an alley, you'd probably need to justify missiles with warheads rather than kinetic munitions. Pseudovelocity missiles maybe? Or in Star Wars-level stuff acknowledging that space speeds are substantially under 0.5 mps.

Yes, something like this. Missile damage is multiplied by speed and can easily grow to levels that one shot the largest ships.

You could also try saying that all Spaceshiips Force Screens are like UT Barrier Screens and form a sphere some distance away from the ship. If all KE missiles explode when they hit a screen that reduces damage. Effectively only proximity hits woudl be possible.

However, that won't be enough by itself. Even at only 7 miles per second a kinetic missle explodes with force equal to 20x it's weight in TNT (and that's the whole missile weight and not just the warhead). Damage will go up as the square of velocity. Levels equal to nuclear warheads are easily possible.

For example, One set of ships launches from Mars at 1G and another set launches from Earth as soon as possible to intercept them. At close approach the trip would take only 2 days.

86400 seconds (1 day) x 32 fps equal 523 miles per second. The two fleets would apss each other going over 1000 miles per second. Unless I'm doing the math wrong that would result in explosions with each lb or missile weight equal to over 200 tons of TNT. The ships could probably fire buck shot at each other with lethal effect.

[Ulzgoroth]

Originally Posted by vierasmarius

Something to consider in regards to nuclear warheads is the "Taming Explosions" damage option in Pyramid 3/34. This changes large explosives (above 100lb TNT equivalent) to use cube root of weight instead of square root, so they scale better with the HP of large vehicles. This drops the 25kt warhead from dDam 4d x 1000 (in vacuum) to around dDam 4d x 140. Not sure if a proximity blast should remain at 1/100 damage; if so, a 16cm nuke is far less scary, inflicting only about 20 dDam from a proximity detonation.

Proximity detonation of nukes is a relatively unimportant consideration, really. The +4 to hit is nice but the really important thing about prox detonation is delivering large numbers of fragments to overwhelm PD, and nukes don't do that regardless.

However, it does allow for really large vehicles enduring or even (with extremely heavy armor) shrugging off small nukes.

[Ulzgoroth]

Originally Posted by Fred Brackin

For example, One set of ships launches from Mars at 1G and another set launches from Earth as soon as possible to intercept them. At close approach the trip would take only 2 days.

86400 seconds (1 day) x 32 fps equal 523 miles per second. The two fleets would apss each other going over 1000 miles per second. Unless I'm doing the math wrong that would result in explosions with each lb or missile weight equal to over 200 tons of TNT. The ships could probably fire buck shot at each other with lethal effect.

Only ships with powerful superscience drives would be able to pull of a maneuver like that. And if they did it would actually be hard for them to hit anything, with about -18 on the attack roll (the PD would take -6, if you managed to hit despite those numbers).

However, you don't need anywhere near such extraordinarily high velocities for KK missiles to be devastating.