Dead in space , The end in Spaceships & Vehicles
uncle_jimbo Nov 6 2017, 20:04 Group: Grid Cop, 5éme Corbin Quote Post
This isn't about zombies, though I haven't forgotten. I was thinking for several reasons about boarding actions. Salvage from derelict ships and stations has naturally come up before. These call for some details of the state of ships defeated in space combat.

A crew can choose to flee, surrender or take to the life pods, if they have any, when they consider the battle is going badly. They may not care to surrender, though, may expect to be killed anyway or may not be able to communicate. The attacker then silences resistance from the vessel with weapons fire.

The enemy or another crew who find the wreck later may want to recover survivors, loot or information, or make what use they can of the ship itself. Finally, player characters in this situation will be interested in what, if anything, they can do.

In the final bombardment, each hit for Mortal or Critical damage is likely to cause system failures that may in themselves disable the vessel or cause catastrophic explosions. Malfunctioning but not destroyed life support may cause hostile conditions.

When a ship loses all Critical points:
  • Determine the location of the last hit. This damage zone is completely destroyed. All systems in the zone are destroyed. Crew and significant loose objects in the zone take secondary damage, then if they are tough enough to survive, are ejected into space. A wrecked ship may have a series of central zones across the hull destroyed, leaving viable zones forward and aft, indicating that the ship breaks into two pieces.
  • All power distribution fails. All ship's systems stop working. Certain systems, such as airlocks, have manual operation modes for emergencies (slow and strenuous) but others can't operate unless supplied directly with power from another vessel (Technical Science-juryrig to connect).
  • All life support functions fail. The ship is dark and in zero gravity (if it used spin gravity, it may tumble wildly or unbalanced momentum may cause further destruction). Air and water circulating in the vessel vent into space. Any survivors not in space suits quickly perish, while those who are in space suits expire more slowly. Areas exposed to inner-system starlight begin to heat up, while those in shade begin to cool. Intact life support systems each contain one cargo unit of compressed air and one cargo unit of water, or equivalent fluids for other biochemical series.
  • The vessel can't succeed on crew checks except to repel boarders, or System Operation checks. If another result calls for such a check, it fails.
  • A plume of gas, ice and debris is obvious on hi-res video, maybe to simple observation, and could become a hazard to approaching small craft or space-walkers. Over time, the volatile components disperse.


This post has been edited by uncle_jimbo on Nov 7 2017, 06:27
uncle_jimbo Nov 7 2017, 05:50 Group: Grid Cop, 5éme Corbin Quote Post
Author (uncle_jimbo @ Nov 7 2017, 07:04)
Air and water circulating in the vessel vent into space.

Actually, while this has certain advantages for gameplay, it's probably inaccurate. Warships rules don't use pressure compartments, but sensible spaceship design does, so it's more likely that parts of the ship - maybe a considerable part - will retain atmosphere behind multiple sealed hatches.

This means, unfortunately, we might need to make some dismal calculations for how long air pockets last without replenishment (unless they're considerate enough to freeze out when the ship's temperature drops into the low Kelvins) and plan for space marines to train a lot to breach closed pressure hatches. That sounds gruesome.

Author
The boy stood on the burning deck
Whence all but he had fled;
The flame that lit the battle's wreck
Shone round him o'er the dead.


Flames in a space habitat are horribly dangerous, but only when there's oxygen. Energy surges from high-powered systems seem common in the movies, but only when there's power. A thoroughly wrecked ship is probably past these.

Despite Star Trek, space battles don't tend to result in contusions and torn uniforms. You might get a few smudges on your spacesuit, be asphyxiated or be vapourised. If your ship wins, you could be extremely fortunate to be the one person in your work area who survives, minus limbs, eyes or lungs. The dead in a derelict, likewise, might either be intact, floating in clumps where they ran out of air, or greasy soot on melted deck plates.

Which reminds me of a couple of things - There will be a lot more battle-ruined starships, comparatively, to explore than we might be used to. Starships and starship power systems don't randomly explode when damaged - why would someone build a starship that way? PL 3 to 5 warcraft often explode, because they're full of chemical explosives, and so much more so, PL 5 surface-to-orbit spacecraft. An ion drive or a laser battery has no similar contents. As I've mentioned elsewhere, if you crack open a fusion reactor, the first thing that happens is that the fusion reaction stops and the second is that a few atoms of hydrogen drift away. We don't know exactly how duodecim behaves, but it stands to reason that it's even harder to get it to react energetically (otherwise we'd already see it doing so).

Nuclear fission reactors also don't go bang, but do melt and spew horrible radiation around, so it's fortunate that in Alternity standard assumptions nobody has used them for centuries.

Wrecked watercraft sink into a medium that humans can't easily see through, that standard vessels can't easily travel or work in, and that corrodes and breaks apart remains. None of this is true of vacuum.

On the other hand, gravity pulls space debris into far more destructive reactions, eventually.

This post has been edited by uncle_jimbo on Nov 7 2017, 07:08
cobalt_phoenix Nov 7 2017, 06:50 Group: Heroes, Status +10 Quote Post
Author
Despite Star Trek, space battles don't tend to result in contusions and torn uniforms. You might get a few smudges on your spacesuit, be asphyxiated or be vapourised.


I can think of one more: spalling damage (which would be similar to a fragmentation grenade). Adjacent sections and compartments around the area of impact will likely see significant amounts of energy traveling through the bulkheads (think of them as pressure/sound waves). While the impacted section is vaporized, the pressure waves are likely to cause bolts, screws, pipes, the works to be smashed off the bulkheads in a shower of splinters.


Author
Actually, while this has certain advantages for gameplay, it's probably inaccurate. Warships rules don't use pressure compartments, but sensible spaceship design does, so it's more likely that parts of the ship - maybe a considerable part - will retain atmosphere behind multiple sealed hatches.

This means, unfortunately, we might need to make some dismal calculations for how long air pockets last without replenishment (unless they're considerate enough to freeze out when the ship's temperature drops into the low Kelvins) and plan for space marines to train a lot to breach closed pressure hatches. That sounds gruesome.


Most spacecraft in science fiction usually have sufficient air volume to keep the crew alive for days if not weeks. I remember seeing some rough figures based on canon info on the Enterprise D from TNG, with its 1000 crew members, and there was never any way for the crew to be incapacitated due solely to a loss of life support in mere hours, much less minutes. In essence, most of the rules governing how long a crew can last without life support are usually grossly under estimated (unless the system is what is keeping the ship's habitable areas cool).

With that said, I could see that all of the damage control systems include a couple of tanks of "back-up" air intended to refill damaged compartments after decompression.

There is also the option seen in the show The Expanse, where the crew pumps nearly all of the ship's air into holding tanks during battle.
derek_holland Nov 7 2017, 15:02 Group: Heroes, Master of Mutant Creation Quote Post
I agree for ships up to PL 7. The Matter and subsequent ages may have technology that reacts chaotically to lost power and destroyed sections. Who knows what might happen to the crew and those who explore the hulk.
cobalt_phoenix Nov 9 2017, 16:28 Group: Heroes, Status +10 Quote Post
Thinking some more on this, you may consider taking a look at wreck diving and cave diving. I can imagine these two have a number of similarities to exploring an old blasted-up ship hulk.

Yes, there isn't enough pressure to have any worry of the bends, but there are a number of hazards. Damaged components are scattered and potentially floating in the free-fall environment, narrow passages with buckled bulkheads can tear e-suit hoses and life lines, and it can become easy to get lost. You may also have considerable temperature differentials (a ship destroyed away from a planet but now in orbit of a star may have one side facing said star, without anything to shade it; that should heat one side to be much higher than the dark side, so you end up with a Mercury-like environment).


Also, I have a feeling that the amount of a ship that does survive combat is much less than what is normally estimated. While spacecraft can't sink (so a single strike to a vulnerable, critical spot isn't going to be fatal), good spaceship design should also include heavily distributed systems. Have you ever designed a ship with a single large reactor? I know I haven't, instead favoring a larger number of smaller reactors, which are usually spread throughout a ship. As a result, cutting off "main power" is just a local issue, not a ship-wide problem.

Yes, the ship will lose some of its capabilities, but it still won't be a sitting duck. I also distribute the engines, just to make sure. As a result, the amount of damage actually needed to kill a ship (especially a military vessel) should be really high. And when you look at the damage potential of some Warships weapons, I have a feeling you are going to meet or exceed the requirements to turn a ship into multiple small chunks. A single shot from the fusion bore will seriously harm a cruiser, but it could still potentially keep fighting (though not anywhere near the way it was before), but a couple of hits should turn most of it into slag. I have a feeling that will be true for most combat wrecks.


Author
This means, unfortunately, we might need to make some dismal calculations for how long air pockets last without replenishment (unless they're considerate enough to freeze out when the ship's temperature drops into the low Kelvins) and plan for space marines to train a lot to breach closed pressure hatches. That sounds gruesome.


That isn't as bad as it sounds. Again, it should take a shockingly long time before a ship interior loses enough oxygen or builds up enough CO2 to be hazardous. On Kursk, the survivors were still alive at least 4 hours after the initial disaster, and potentially could have survived for days longer (if an oxygen candle hadn't been dropped into sea water).

For marines breaching a pressurized compartment, the best way is to just blow the door with a small shaped charge. The charge will punch through the door, initially creating a pressure wave in the compartment, and then explosive decompression kicks in. If that won't mess up the defenders, I don't know what will (tossing a flashbang into a room does a wonderful job, so this should be similar). Just make sure the marines hit the hatch and open it the moment the initial fireworks end.



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