Standard deck plans assume a 3.0m height. 3.0x1.5.x1.5x8 = 54 m^3. Divide by 13.5 = 4 tons. The 3.0 m includes deck bulkheads and some piping, ceiling lights, local grav plates, etc.
Mostly, I looked at cruise ships just for a restricted-space comparison of double occupancy (as opposed to single occupancy) that could be considered luxurious (as opposed to steerage). I said that using 4dT to account for "galley, pantry, gangways, and other common areas… would be generous to the point of wasteful."
In that you can get by using the half size staterooms and still devote enough space to have communal showers, a galley, some limited storage space... I suppose you could say so. But having that extra doubling of space will merely make your cabin a bit more like a room and not a closet and won't make the remaining space 'luxurious to the point of being wasteful.'
As for life support & sealed environment, that is part and parcel of ship design as a whole. That's why starship hulls cost 20-100k/dT empty: rad shielding, buffered auto-sealing materials for micrometeors, wiring, piping, etc are included.
It is also why staterooms are 4 dtons.
Later design rules account for life support tonnage and costs separately yet still cite 4dT (and the mysterious 2000/jump overhead).
What exactly to you mean by 'later'?
C'mon, I don't think 4dT was ever supposed to account for "pool halls, swimming pools, shuffleboard tables, dance ballrooms, etc." Do you really?
How about hallways? Ever seen how much space they eat up on a cruise ship? How about heads? How about showers? How about storage closets?
I think you'll find if you look at any ship designed for long term habitation, these take up a fair portion of ship interior space. And since these are NOT accounted for elsewhere, staterooms are the catch all (and not inappropriately, as most are living space related requirements).
If you want those on your ship, add rooms sized and designated for the purpose. Allowance for passageways is reasonable and nothing more required. Especially for standard sub-1000dT ships.
Almost *EVERY* traveller deck plan falls short on what would be required storage wise. Figure out what you'd need for survival, ship repair (everything from a busted navicomp to a total manual reinstallation of zuchai crystals or whatever, plus welders, hydraulic rams, etc), emergency supplies such as vacc suits, water, medical supplies, rescue balls, firefighting gear, etc. You'll find nearly every official and unofficial design comes up far short.
The overage on stateroom space is the only place you can account for this.
Sounds to me like you don't want high guard or even MT ship construction, you want striker ship construction where you get to individually decide how many bolts you get to put on the bulkhead... that's the only way you'll explicitly see all of this stuff accounted for.
Another thing about travel economics: low passage. A cold sleep berth is, in essence, a piece of medical equipment. In today's economy, a hospital room is more expensive than a luxury hotel room. A pint of blood is more expensive than the finest wine or caviar on Earth. Imaging and lifesign monitoring is high-tech, high-price equipment.
Imagine that you are utterly against canon too.
The Cold Berth is a commodity shipping container whose cargo just happens to be organic. Essentially, it has to be self-contained and battery operated and you can thaw and unthaw with very minimal training (Med-1 or Med-0, though reputable doctors are usually present on good liners). It is hardly high tech, compared to many of the other ship systems. It is a commodity item....
Sure, in Traveller the tech is well developed and benefits from economy of scale. The initial cost is going to be high just because a life depends on the flawless operation of the equipment. Maintenance is going to be costly as well.
Or not.
And the life depends as much on the astrogation systems, the carbon dioxide filters, the ship's sensors, the ship's engines, the hull, the ship's avionics, the environment monitors, the grav plating (in that it does not catastrophically malfunction), the water purifiers, etc.
The cold berth is neither the only nor the most important piece of ship gear and far from the most complex. The Jump Drive kicks its behind....
Even then, the odds of surviving is worse then a term of service in the military! Picture in your mind an activity that incurs a 16% chance of death, or if attended by a fully qualified doctor, an 8% chance of death. I'm not sure that open heart surgery is that risky today; I am sure that in Traveller tech it isn't.
This is admittedly a weakness in canon, at TL of the low berth or medical facilities plays no role, which is ludicrious. Open heart surgery, counting complications from strokes etc, probably is that risky. And in many places, even childbirth is riskier than that.
Not saying it isn't a stupidly high risk.... but it does promote an image of the desperate travelling that way and those who have no other option but just *have* to travel.
IMTU, I use someone's suggested reductions in mortality based on TL of the Berth and the revival facilities. The canon implication is that tech advances don't make this process less dangerous or more perfected, which runs counter to the progress of every other trav tech stream....
No, the only time you want cold sleep is for extended travel, like sub-light interstellar or really primitive chemical rocketry interplanetary trips. Maybe if a low passage was over many jumps, essentially mailing yourself across a sector or two, that could justify the extreme risk.
Or if you need to go into it as an emergency when the ship is damaged.
Instead there should be an economy class ticket for double occupancy bunks in a half-sized room, with limited common area priveledges (a short period each day to stretch and walk a bit). Decent auto-galley fare. Think sleeper compartment on a train. Price (J-1) would be about 2k, or 4k Private compartment single occupancy.
Oh, that much I agree with. There should be a bunk-rack style of transport with limited movement and galley and head priveledges. Life support expenses are constant, but other associated expenditures of space and support would be lesser.
There might also be 19th century type steerage: an open space with benches and hammocks, with limited space for personal belongings including food under the bench. That would be the 1k J-1 ticket.
Yes, we call this 'the cargo hold' and it hold such hammock passengers and MREs. OTOH, if hte imperial authorities catch you spacing without at least a rescue ball for every person aboard, they'll hit you with some hefty fines. (Think huge ferry disasters like we see in Europe/African near waters....