I wrote this up last night, but the combination of the CotI tokens and Firefox ate it.
The costs for running a ship are in GT:Starships, p. 27. They include the following:
* Ongoing Maintenance Spare parts: 0.1% original ship cost per year
* Annual Maintenance: 0.1% original cost per year
* Fuel : Cr 350 / dton refined, Cr 50/dton unrefined.
* Salaries: Cr1120 / person per month, plus Cr200 per month for Captain and other section heads.
* Fresh Food for passengers and Crew (Cr6 to Cr60 per person per week).
I built a series of 200Dton tramp freigher at each of the J1 - J6 drives, with the other standards given above.
Jump | Cost (MCr) | Cargo (Dtons) | Maint/jump | Crew Salaries | Fuel | Cost/jump | Cost/DTon |
J1 | 27.9 | 148 | Cr2232 | Cr3460 | Cr7000 | Cr12692 | Cr86 |
J2 | 36.6 | 127 | Cr2928 | Cr3460 | Cr14000 | Cr20388 | Cr160 |
J3 | 45.9 | 105 | Cr3672 | Cr3460 | Cr21000 | Cr28132 | Cr268 |
J4 | 54.5 | 84 | Cr4360 | Cr3460 | Cr28000 | Cr35280 | Cr426 |
J5 | 63.2 | 63 | Cr5056 | Cr3460 | Cr35000 | Cr43516 | Cr690 |
J6 | 72.6 | 41 | Cr5808 | Cr3406 | Cr42,000 | Cr51,268 | Cr1250 |
Okay, so comparing this data to the Book 2 data and recalling some of the other information we've discussed, we have GURPS ships operating at much reduced cost, able to deliver cargoes much more cheaply, and those cargoes average a higher value to begin with. It's practical for a ship to deliver cargo profitably even at jump-6: with planning, the cost of a jump-6 transport is 24% of the average cost of the cargo.
Put another way, cargo can travel 4 or 5 times as far in GURPS for the same price - as a percentage of its value - that it costs to move one parsec in CT. So, what we need to do is figure a way to calculate the BTN numbers as if the ranges were five time what they were in GURPS. Near as I can figure, that chops things by something between an order of magnitude and an order and a half. There's also that very-long-range strangeness, but trade drops away pretty quickly with distance.
Which means CT trade volume is? The 1-parsec traffic's 1/10 the GURPS volume, the 2 parsec and 3 parsec traffic's 1/100 the GURPS volume, based on multiplying the ranges on page 15 of
Far Trader by 5, 4 to 5 parsecs gets to 1/316 the GURPS value, and above is small enough not to bother counting - there'll be some high value stuff, but it's a very tiny percentage of the overall volume. Now I know GURPS does long-ranges, but if I have the system right, about 58% of the traffic was jump-1, a bit under 32% jump-2, a bit over 10% jump 3-5 or higher. I read the end result as CT being a bit under 6% of the GURPS trade volume.
Wow. Well, that's a number. Might be a bit of fudge factor in there, but I think it's pretty good. Even gives us a rough idea of how much Jump-2 and Jump 3 traffic there is, assuming we're still applying the GURPS paradigm, which is to say if I read it right that 99.4% of traffic overall is jump 1, about 0.5% Jump 2, and 0.1% Jump 3. I don't know that I want to take it that far, but mathematically it seems to work.
So:
1) Those red routes are doing an average 50-60 dTons of cargo weekly, seeing 1 to 2 ships every 4 weeks. The subsidized liner might have a route taking in three stops.
2) The yellow routes are doing on average 5-600 dTons of cargo weekly, enough to support a couple of 4-600 dTon ships and maybe a couple or three free traders, seeing about 2 ships a week.
3) The green routes are averaging 5-6000 dTons weekly, which will support a few large freighters and some smaller freighters and free traders, and see about 3 ships a day.
4) The aqua routes are averaging 50-60,000 dTons weekly, which is maybe 40-50ish large freighters of varying sizes and a large number of smaller freighters and free traders. The port is active, with 20-30 ships a day.
5) The big blue routes are averaging more like 5-600,000 dTons weekly, which supports a few megafreighters and a large number of large freighters and smaller ships.
This all presumes a 1 parsec jump. 2-parsec routes and 3 parsec routes drop two levels from their current. Mora's once-blue connection with Fornice, for example, becomes a green route. The green 2-parsec routes out of Porozlo become red. A lot of places become pretty isolated, seeing only the occasional adventuring free trader or far trader.
That seems to be what we get if we apply GURPS paradigm to CT's shipping costs. Thoughts?
Add: oh crud, it changed. I gotta recalculate this?
Add: no, I think I'm OK. Shipping cost comparisons are based on the fees charged in GURPS
Far Trader, Page 22. As long as the GURPS ships can move cargo profitably at those rates, the comparison still applies.