baithammer said:
Bulk cargo also doesn't require time efficiency that fast transports live or die on, the point is to deliver mass amounts of cargo at a regular time frame. ( Looking at Jump 1.)
I agree that speed is not all that important for many goods, but shipping long distances it's actually cheaper to use higher jump, say J-3.
Example: Shipping an idealised 12 Pc takes 12 jumps at J-1, 6 jumps at J-2, 4 jumps at J-3, 3 jumps at J-4, and 2 jumps at J-6.
Making simple freighter of 20 kDt with the different jump performances:
Jump ___ Cost _______ Cargo
J-1 ___ MCr 1671 ___ 16560 Dt
J-2 ___ MCr 2350 ___ 13840 Dt
J-3 ___ MCr 3030 ___ 11110 Dt
J-4 ___ MCr 3712 ____ 8380 Dt
J-6 ___ MCr 5087 ____ 2940 Dt
Running costs are basically proportional to cost, so I'll only use cost.
Each ship jumps as quickly possible (9 days/jump) to the destination, spends a week loading/unloading, and then jumps back. With this we can calculate how many trips each ship can make in a year, and so how much cargo it can ship in a year.
Jump __ Trips/y _ Days/trip ______ Calculation
J-1 ______ 1.6 _____ 223 days ____ 12 × 9 + 7 + 12 × 9
J-2 ______ 3.1 _____ 115 days _____ 6 × 9 + 7 + 6 × 9
J-3 ______ 4.6 ______ 79 days _____ 4 × 9 + 7 + 4 × 9
J-4 ______ 5.9 ______ 61 days _____ 3 × 9 + 7 + 3 × 9
J-6 ______ 8.4 ______ 43 days _____ 2 × 9 + 7 + 2 × 9
So, a J-2 ship will take 115 days for a round trip, doing 3.1 trips in a year.
With this we can calculate how much cargo each ship can carry all the way to the destination in a year:
Jump __ Trips/y ___ Cargo ____ Cargo/year ___ Cost/Dt carried
J-1 ______ 1.6 _____ 16560 Dt ___ 26496 Dt _______ kCr 63
J-2 ______ 3.1 _____ 13840 Dt ___ 42904 Dt _______ kCr 54
J-3 ______ 4.6 _____ 11110 Dt ___ 51106 Dt _______ kCr 59
J-4 ______ 5.9 ______ 8380 Dt ___ 49442 Dt _______ kCr 75
J-6 ______ 8.4 ______ 2940 Dt ___ 24696 Dt ______ kCr 206
We can see that the J-2 ship is cheapest, with J-3 almost as cheap. J-4 and higher is much more expensive.
Interesting, it's usually J-3 that is cheapest, as far as I can remember.