Starship Economics, Book 2

[BetterThanLife]

I do stand corrected about SCUBA tanks capacity. It is 80 cubic feet of air at about 2700 PSI. That is the standard tank. That works out to about 2265 liters of air. At 48l per day that gives you enough air for 47 days. at 48l per hour that gives you about 2 days of air. The standard 80 tanks are rated for a half hour of air with a small reserve for the average diver. A tourist diving for fun isn't going to lug around 2 days of air when an hour or two would allow plenty of safety margin.

 

[Anthony]

Originally posted by Fritz88:
But, of course, you don't store O2 in a SCUBA tank. You store air. If you only stored O2, there would be all kinds of physiological problems with diving. And, that is a big reason they don't last that long (you're not using a large portion of the contents).

Sure, but the nitrogen can be recycled 100%; what you need to do is replenish the oxygen and remove the CO2 (removing the CO2 is a problem sooner than replenishing the O2).

 

[hcobb]

I would store oxygen in the ship's fuel tanks.

A human being requires 0.83 kg of Oxygen a day.

Since H2O is 88% Oxygen by weight this means that 1 dton of Water will provide 40 man-years of Oxygen.

You just need a device that will skim off the 1.55 dtons of hydrogen from the 1 dton of water for use in your jump drive.

 

[BetterThanLife]

Originally posted by Henry J Cobb:
I would store oxygen in the ship's fuel tanks.

A human being requires 0.83 kg of Oxygen a day.

Since H2O is 88% Oxygen by weight this means that 1 dton of Water will provide 40 man-years of Oxygen.

You just need a device that will skim off the 1.55 dtons of hydrogen from the 1 dton of water for use in your jump drive.

Oxygen density is .001429grams/cubic centimeter. Which means 1.429grams/liter. So .83KG of Oxygen would be 1186.07Liters. That is quite a difference from 48L per day.

So a SCUBA tank with those numbers and a 79%/21% mix, would have air for, about 2.6 hours. Now that sounds much more reasonable. If you carried Oxygen, and used your lifesupport to mix in the Nitrogen, Each SCUBA tank equivalent of Oxygen would carry about 1.9 days of Oxygen. Average SCUBA tank displaces about 17 liters (Exterior size). So 14 days of oxygen would then be about 125liters. Now that fits in a starship.

Further you would need a few tanks of air to pressurize the hull, and be able to repressurize the hull in the event of hull breach, etc. But at 2.6 hours per person, per tank, per 2 week period, carrying air is 4394 Liters, or 4.4kl, per double occupancy stateroom per 2 weeks. So it would fit without all the fancy cracking or mixing. (Using cracking and mixing to maintain pressure in the ship.)

BTW at 9.2 tanks a day per person that would lower the air portion of your lifesupport to around Cr10 per day.

Just when I thought I found a major cost factor in the KCr1 per week. RATS!!!

 

[hcobb]

Let me restate this then.

Any jump ship with a fuel processor that refuels once from a water or ice source will produce more waste oxygen than the crew and passengers will require in the rest of their lives.

 

[BetterThanLife]

Originally posted by Henry J Cobb:
Let me restate this then.

Any jump ship with a fuel processor that refuels once from a water or ice source will produce more waste oxygen than the crew and passengers will require in the rest of their lives.

True. However it definitely isn't getting us any closer to KCr1 per week for Lifesupport. (Or KCr per 2 weeks.)

 

[Fritz_Brown]

OK, so how does a liner make money? After putting together a LBB2, 500dT, 35 Hi-Pax/20 Lo-Pax liner, I show it making 1/2 the necessary monthly payments. And, yes, that is making two J1 trips a month (and not taking into account the annual maintenance period). Even with the stewards running double duty as gunners (all but the chief gunner and a chief steward), and using their 4 staterooms, I get only about 60% revenue required.

(Its 500dT, M2, J2, 20 Lo-Pax, 35 Hi-Pax, 15 crew without double duty, 263MCr cost.)

Edit: Oh, almost forgot: Thread Ressurect!! end edit

 

[far-trader]

Well without even seeing the design if you're going strictly by the book I see a few problems, er oppurtunities to gain more credits right off...

First 500ton hulls by LBB2 are a bad choice. You don't get the cost benefit of a standard hull for one and have to use drives rated for a 600ton hull for another. The second part wastes space (revenue) and money. Pick a standard hull (under 800tons) and stay within the Drives space.

Second is the 2G maneuver drive. Not really needed in most cases, 1G saves space and money.

Third even if trading exclusively between two high pop, similar TL, systems you'll only rarely fill all those staterooms with high passengers, so you could cut back on that some.

Fourth if it is between two high pop, similar TL, systems you could bump up the lowberths. You'd be routinely turning away a couple passengers there, and they don't require Stewards.

Fifth is the mention of gunners (plural). If it's that dangerous ok but generally all you should need is one, and that simply for the chance to snag a mail contract. Weapons are pricey.

Sixth is the crewing in general. You have: Pilot, Navigator, 2 Engineers, 5 Stewards, Medic, and 5 Gunners (if not using double duty). A better mix would be double duty for all as: Pilot/Navigator, Engineer/Gunner (for the purists who think simply doing Engineer/Engineer is wrong), Engineer/Steward, and Steward/Medic, adding any local kid as a working passage Steward when you have the extra high passages booked, or making that the Chief Steward/Owner Aboard. So a crew of 4 (or 5) and 24 passage staterooms for up to 24 high passagengers.

Of course, all that said if this is a subsidized ship you can ignore the economics

It's a "job creation program" and losing money is not an issue

Oops, almost forgot one more possible area to cut back, the computer of course. All you need is a model/1BIS and try to avoid pricey programs like combat ones. Stick to the minimum there, try to go with just Target and limit that one turret to a pair of pulse lasers. And that only if you absolutely must be armed

Don't take any of this the wrong way, I'm just trying to show where you might make some gains on the bottom line.

 

[Straybow]

Where's the fun in that? If I were legally permitted to mount a .50 on a ring over the sunroof on my car, I'd mortgage my soul to pay for it.

Far Trader cargo/Freight manifest questions shows that LBB2 can only logically be read to mean charges are per parsec. Someone also said it on p1 or p2, but I also make a point about the LBB 20 ton bridge rule being excessive in the extreme. Correcting the two a Scout can make money in bulk shipping.

Price-Fixed Travel has some discussions about LBB2 design requirements: stateroom size, etc.

Making a Jump 2 freighter profitable. I'll summarize in one brief quote:

/me stirs up trouble

Change commodities to mass tons instead of dtons. Even if you limit the load to 2 tons per dton (instead of 5T/dT) in order to keep within the jump-2 mass limit, your initial calc becomes a 60k/mo profit instead of 70k/mo loss.

Traveller Cargo Standards is where I attempt to do just that.

 

[Fritz_Brown]

Well, FT, you are right about the 500 dTon hull, though I called it a standard design.
(Edit: Actually, a standard hull. I forgot to figure in the standard design discount, which will make it a little more affordable.)

But, even figuring with the reduction in M-drive (and even a J-1) you don't appear to save enough money to make the payments. Cutting out the stewards only saves a few kCr per month. (Shaving off a few programs would help, as I went over the 4MCr allowance. A smaller computer make some sense.)

The largest piece is making that 1.1MCr mortgage payment. That is followed by the life support costs: 102KCr a month!

It looks like the only way to make money is by hauling cargo, not by hauling people.

 

[Whipsnade]

Originally posted by Fritz88:
It looks like the only way to make money is by hauling cargo, not by hauling people.

Fritz,

Then haul people as cargo.

Check out the profit from a dTon of low berth passengers compared to the profit from a dTon of freight. Get any ideas?


Have fun,
Bill

 

[Fritz_Brown]

Ah, yes, the .5dT=1KCr for paxsicles vs the 1dT=1KCr for cargo! That might be doable with the bit of cargo space left in this design. (18dT of the cargo space is a freezer, anyway. Of course, the cook might not appreciate that......)

(BTW, who uses the 1000kg baggage allowance for hi-pax and allots a whole dT to it?)

 

[Fritz_Brown]

Oh, and this deckplan was hard enough to do, I don't plan on redrawing the thing. It will just have to work as is. But, putting in the smaller drives would bring the cost down to a more reasonable bit.

(BTW, I have about 50dT just for the lounge/restaurant/club on this ship. It may not be canon, but I think I should charge more. )