Scout Cruiser Reworked
- Thread starter Patron Zero
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Icosahedron
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Bear in mind that just because a vessel is 'vacuum sealed', it doesn't necessarily mean it's waterproof. Vacuum is a negative pressure of only one atmosphere. Water pressure is positive (bringing different stresses on the hull) and varies by 1 atm per 10 metres depth.
If you park your ship on the bottom of a 30m lake, the hull has to withstand 3 times the vacuum stress in the opposite direction. That's no mean engineering feat and it may be another reason ships need to be specially designed for water landings. A large ship could find its lower extremities have a couple of atm on them even when the ship is floating.
A spaceship is not automatically a submarine.
If you park your ship on the bottom of a 30m lake, the hull has to withstand 3 times the vacuum stress in the opposite direction. That's no mean engineering feat and it may be another reason ships need to be specially designed for water landings. A large ship could find its lower extremities have a couple of atm on them even when the ship is floating.
A spaceship is not automatically a submarine.
far-trader
SOC-14 10K
True, but Traveller spaceships seem to presume, even for unarmored hulls, a strength and rigidity far in excess of a simple space craft. Probably rivaling if not exceeding that of our current submarines. There are also cases to be made for if not examples of routine operations of standard streamlined ships operating in oceans at depth. Armored hulls can go even deeper. I have no problem with any streamlined design sitting under a few atmospheres of pressure nor even operating at that depth like a submarine, including sensors. It's all part of the cost of streamlined hull design. And one more reason unstreamlined ships shouldn't land in any atmosphere, just like Traveller says they can't. They'd buckle in under even partial atmosphere pressures.
and how deep into a gas giant do you go to skim for fuel? There is bound to be significant pressure as well as extreme turbulence perhaps, depending on the layer you are in and how far down. So if a ship can fuel skim from a gas giant, then I would think it should be able to handle a few atmospheres of water pressure, particularly if the water is relatively still versus however fast fuel skimming goes.
Reminds me of the scene in 2010 when they were aero-braking across Jupiter: everything is shaking, groaning and loud. Hope fuel skimmers have some good sound insulation!
Reminds me of the scene in 2010 when they were aero-braking across Jupiter: everything is shaking, groaning and loud. Hope fuel skimmers have some good sound insulation!
The ships are also designed to withstand gravitational forces up to and in excess of their M-drive rating. Simply accounting for a M-2 drive on a streamlined hull configuration landing and taking off from a standard 1G planet, the ship itself will need to be "beefy" enough to withstand 3-Gs, max. Should allow for water landings, all else equal.
And I personally presume that the ships will be floating, not submerging. Although i can see call for either scenario.
far-trader
SOC-14 10K
However, since Traveller allows fuel skimming by partially streamlined ships we have to presume that the operation is conducted very shallowly and slowly indeed. The upper atmosphere of a gas giant is going to be comparable to very thin atmosphere at the most. I know, never made any sense to me either.
Yep, that's how it should be. Of course they were using the atmosphere to aero-brake, not attempting to simply process some rarefied gasses while loitering in it. Still I agree, GG skimming should involve a lot of shaking, heat, radiation, danger. All things to be avoided and left only to the best pilots in properly designed ships and in desperate circumstances. NOT your typical merchant in a free-trader of questionable repair with passengers and freight paying for safe transport.
Patron Zero
SOC-13
This may be a fodder for discussion in a new thread but the gist has been mentioned here.
I've often wondered if the hulls of starships are similar in design to modern day submarines, essentially might there be a 'double' hull present in in such as in said wet navy vessels.
Part of my 'wondering' came after watching the film, U-571, the scene in particular when a rating was sent 'between' the inner and outer hulls to effect repairs, I could see such an action also taking place onboard a starships under similar distress.
Mind that's strongly flavored by my take on starships, more naval-military craft having the gritty feel of WW1-WW2 submarines as well as the often depicted cramped near-claustrophobic compartments with exposed piping and conduits.
I've often wondered if the hulls of starships are similar in design to modern day submarines, essentially might there be a 'double' hull present in in such as in said wet navy vessels.
Part of my 'wondering' came after watching the film, U-571, the scene in particular when a rating was sent 'between' the inner and outer hulls to effect repairs, I could see such an action also taking place onboard a starships under similar distress.
Mind that's strongly flavored by my take on starships, more naval-military craft having the gritty feel of WW1-WW2 submarines as well as the often depicted cramped near-claustrophobic compartments with exposed piping and conduits.
Drakon
SOC-14 1K
To be specific, the crewman was in the engineroom bilge while the ship was flooding. Submarines do not not exactly have a double hull. They have tanks external to the living spaces, and a superstructure, but no real external hull.
But I know what you mean, and feel that starships would have a very sturdy hull, more like a sub. Of course I served aboard subs, so can't claim an unbiased position here. Frountier landings and general waterproofing along with the sturdiness of the hull should give it the capabilities to submerge.
But I know what you mean, and feel that starships would have a very sturdy hull, more like a sub. Of course I served aboard subs, so can't claim an unbiased position here. Frountier landings and general waterproofing along with the sturdiness of the hull should give it the capabilities to submerge.
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at pertinent tech levels, considering just the main hull, it isn't, assuming the ship is maintained and all the gaskets are good. what's tough is dealing with salt water corrosion and marine life.
fusion rockets, exposed gun turrets, sensor points, and external comm panels, however, may not do so well. condensation in a laser system, or a barnacle on a missile launch rail, can make a boring day interesting.
Drakon
SOC-14 1K
Attach zinc bricks directly to the hull, below the waterline. Use a stainless steel or possibly coat hull in some form of ceramic that repels marine life.
Also, I feel the ship's hull should be strong enough to offer some protection during uncontrolled re-entry. Which might be a decent form of hull cleaning. Simply burn it off in re-entry.
So you put these either on retractable masts, or have some kind of hatchway to protect them. Sensors can be placed behind transparent shields or windows.
Icosahedron
SOC-14 1K
Does BSD corrode?
I doubt if barnacles and condensation would survive vacuum.
I wasn't saying above that ships couldn't submerge, just that vacuum tight is not the same as water tight, so it might not be automatic. Most Traveller ships probably are designed with capability for a degree of immersion.
Patron Zero
SOC-13
Could be I'm incorrectly recalling this but believe I read something regarding the tactic of system defense boats laying below the surface of a planet's lake/ocean to avoid detection.
Also if I may pose this question, are small craft, non-jump capable vessels, more 'fragile' than dedicated starships regarding their hull construction?
Also if I may pose this question, are small craft, non-jump capable vessels, more 'fragile' than dedicated starships regarding their hull construction?
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It is in canon, IIRC.
Since they are made to handle, on average, greater stresses, I would say they are stronger. This is a SWAG, though, and would not hold across all equally: I'd say a LBB2 fighter is stronger than a Fat Trader, but that doesn't necessarily mean that a Shuttle is stronger than a Scout-Courier....
Adding armor in HG always seemed a good expedient to justify hull strength. As to MT, I remain largely ignorant, but I gather the principles are the same and the specifics more helpful.
It is referenced somewhere in the CT adventure 'Secret of the Ancients' with regards to atmo pressure limits of spacecraft hulls.
Given that (streamlined) spacecraft can refuel by dipping, and that oceans are a well-established hiding place for mainworld SDBs, it would follow that various spacecraft hulls are hydro-tight to approximately the same pressures that they are atmo-tight.
Drakon
SOC-14 1K
Oh I agree. All I am saying is that while they are different, it is not that difficult to make a ship both air tight and water tight. Bouyancy will be based on ship's density, and fuel/cargo loading.
Not sure what BSD is. I know HY 80 and HY 120 are supposed to be fairly corrosion resistant.
GypsyComet
SOC-14 1K
Have you *driven* Highway 120 recently?
BSD = Bonded SuperDense, a standard high TL hull material in Traveller.
