Submarine Capable Starships
- Thread starter Mithras
- Start date
BlackBat242
SOC-14 1K
I'm sure there are others, but here's what I found:
last post 2009
Operating a starship under water
last post 2009
Operational depth
last post 2007
Floating spaceships
last post 2006
SDBs can go underwater?
last post 2004
Starships underwater
last post 2009
Operating a starship under water
last post 2009
Operational depth
last post 2007
Floating spaceships
last post 2006
SDBs can go underwater?
last post 2004
Starships underwater
Don't know about threads, but I note that Supplement 7's SDB notes that streamlined ships are inherently capable of submarine operations.
There was something more recent, 'cause I've only been here a year and a few months. Dealt with the amount of pressure a starship hull could take and how deep they could go. I think it came up in a post on submarines, some real-world design and what its features implied about spacecraft, if I remember correctly.
Consensus was they could go underwater but not terribly deep - at least as compared with purposebuilt submersibles - unless they were specifically designed for deep water operations like those SDBs Aramis mentioned. Issue is that certain design elements need to be reinforced for that kind of thing - for example the hull can hold, but the ship will still sink if the airlock door collapses under pressure. Similarly, seals at points where wiring and such protrudes through the hull might be up to keeping air in but not up to keeping water under extreme pressure out, resulting in water in awkward places. So there you are, 40 fathoms deep, under a bit more than 8 atmospheres, when a turret seal fails and takes out a million-credit laser - not a happy day.
It might be helpful to think of underwater as a kind of insidious atmosphere with progressively greater danger the deeper you go. Pressure increases by about one atmosphere for every 10 meters of depth, as a rule of thumb. I don't know how deep is safe - there may be canon mentions that clarify it better - but it does get pretty intense pretty quick with increasing depth. SDBs can hug the bottom of the Caribbean a couple or four thousand meters down without apparent difficulty (Invasion Earth), but that doesn't mean your ol' free trader is going to be happy below 30 or 40 meters.
Frankymole
SOC-12
Presumably some worlds are out of bounds: Venus, for example. Exotic atmosphere (value B?), and what about some of the Gas Giants that SDBs hide in?
Vladika
SOC-14 1K
Not all by itself it isn't!
Can't be so large a hull that it's "thin walled". Must have adequate bracing. Etc. etc. etc.
There's a lot more to it.
Even a surface ship is subject to "panting" with those scantlings.
What are you up to this time?
Elsewhere we're having an interesting discussion about windows and viewports in our spacecraft - which I think raises the point that the strongest part of our ship is not the part we need to be worrying about in these circumstances.
Alvin, an older deep sea submersible from the '60's that recently underwent upgrade, has truly massive windows:
"When we set sail later this year, Alvin will have five windows: three up toward the front that are 7 inches across on the inside (17 inches across outside), and two smaller ones off to either side that are 5 inches in diameter on the inside (12 inches across outside). These are considerably larger than the windows we had before.
"The larger sides of the windows face out to the ocean, so that as Alvin goes deeper and is subjected to greater pressure, the windows will be forced inward against the titanium hull. That will strengthen the seal between the window and hull.
"The windows are acrylic, a type of plastic. At a test facility in Texas, the windows were subjected to a test pressure of over 12,000 pounds per square inch. This translates to about 680 tons of force on the small windows, and over 1,300 tons on the larger ones. That is almost twice the pressure Alvin will experience at its current maximum operating depth of 4,500 meters (about 15,000 feet). Eventually, Alvin will be rated for dives to 6,500 meters, or a little over 21,000 feet."
http://www.whoi.edu/oceanus/viewArticle.do?id=159529
The photo shows the window, which I think is around 5" thick if that's a 45 degree pitch.
The International Space Station's portholes are two panes of fused silica glass, each 1.45 inches for the top window, 1 inch for the side, and some space between, and a thin - presumably replaceable - outer layer to handle minor impacts, and a thin inner layer to handle scratches and wear.
http://esamultimedia.esa.int/docs/hsf_research/Climate_change_ISS_presentations/Cupola_Deloo.pdf
That's decent strength, but given their diameter, it's not exactly built for the deep seas. Question is: which type would a Traveller universe builder use in his merchant ships, or would he have something else that offered good or better strength?
And then there are the other potential weak points - basically anything passing through that equivalent-to-33cm-of-steel hull, or anything exterior to the hull. As I said, having a strong hull won't necessarily prevent a seal around your laser from failing and and admitting high-pressure water into the weapon's circuitry.
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Google popped up this nifty tool:
http://www.calctool.org/CALC/other/games/depth_press
SDBs can dive damn deep given the 3000 atm pressure rating mentioned elsewhere. And I do recall somewhere about SDBs on the ocean floor of Terra.
http://www.calctool.org/CALC/other/games/depth_press
SDBs can dive damn deep given the 3000 atm pressure rating mentioned elsewhere. And I do recall somewhere about SDBs on the ocean floor of Terra.
