[Spaceships]Traveller Ships with economics

[Agemegos]

Originally Posted by thtraveller

I would rather be more "realistic".

So would I, especially where the canonical material implies persistent economic disequilibrium (a.k.a. opportunities for [supernormal] profit, a.k.a. "economic perpetual motion machines", a.k.a. "money trees").

Far Trader made an heroic effort at eradicating the money trees in freight transport demand (though I conclude on examination that it ought to have considered J-3 trade routes). I would be nothing averse to attacking the disequilibriums in transport supply.

[Agemegos]

Originally Posted by thtraveller

Comparing the cost per passenger or cargo ton for a range of ships built to the same method as above gives:

Cargo ton per parsec
$900 J2+J2 Cargo Liner
$1500 J4 Cargo Liner

On a 4-parsec leg the J4 saves one week at a cost of G$2,400 per ton. With the interest rate on commercial paper at, say, 7% that's economic on freight worth G$1.7 million per ton or more. I doubt that there is enough volume at that sort of value to keep J-4 lines in business.

Passenger Price* per parsec
$4300 J1+J1 Passenger Liner
$4100 J2 Passenger Liner

The J-2 liner is both faster and cheaper.

$4800 J2+J2 Passenger Liner
$7600 J4 Passenger Liner

On a 4-parsec leg the J-4 liner saves one week at a cost of $11,200 per passenger (middle passage). It will be preferred only by passengers with BVOT of G$1,600 per day or more. That probably includes executives and professionals. But the high generalised cost of a trip (at least G$41,600 one way, including G$30,400 fare plus at least G$11,200 value of time) and the small economic volumes of planets in the TU suggest that potential traffic volumes will be small, probably too small to sustain a line, especially given the sensitivity of such travellers to headway and the long cycle times on thin routes.

$15000 J5 Passenger Liner
$6900 J3+J3 Passenger Liner

The J-5 liner saves one week at a cost of G$32,400 per passenger (middle passage). It will be preferred over the J3+J3 only by passengers with a BVOT over G$4,630 per day. Such people exist, but there probably aren't enough of them to keep lines in business.

J3+J3 liners will be challenged by J3+J2 liners with more staterooms and fewer fuel tanks, which will still further thin the market for J5 liners.

$4100 J2 Passenger Liner
$4800 J2+J2 Passenger Liner

On a 4-parsec leg with a potential refuelling stop in the middle, the J2+J2 saves the trip in from the 100D limit and back and waiting/refuelling time at the intermediate port, at a cost of G$2,800 and the opportunity for a brief stop-over.

[Agemegos]

Originally Posted by thtraveller

$4400 J1 Passenger Liner
$4100 J2 Passenger Liner
$5300 J3 Passenger Liner
$4800 J2+J2 Passenger Liner

Interesting.

Converting those figures to a per-Jump basis for convenience we get:

$4,400 J1 passenger liner
$8,200 J2 passenger liner
$9,600 J2+J2 passenger liner
$15,900 J3 passenger liner
$30,400 J4 passenger liner

Let's consider the route from Regina to Aramis as an illustrative example.

The distance is 12 parsecs, but astrography does not allow a (J2, J2, J2, J2, J2, J2) route. The (J2, J2, J2, J2, J2, J2, J1) route [Regina, Yori, Treece, Kinorb, Risek, Henoz, L'Oeul d'Dieu or Vinorian, Aramis] takes 64.5 days and would cost G$53,600.

[Regina, Yori, Treece, Kinorb, Risek, Henoz, Aramis] is (J2, J2, J2, J2, J2, J3) takes 55 days and would cost G$56,900.

[Regina, Yori, Treece, Kinorb, Risek, hex 2911, Aramis] is (J2, J2, J2, J2, J2+2, J2+2) takes 53 days and would cost G$52,000. It is both cheaper and faster than the route with the extra refuelling stop and the route with the J1 leg.

[Regina, Yori, Inthe, Risek, L'Oeul d'Dieu, Aramis] is (J2, J3, J3, J3, J2) takes 45.5 days and would cost G$64,100. Contrary to the case in Far Trader costs it does not dominate the best six-Jump route: indeed it is preferred only at BVOT above G$1,600 per day, which is fairly high.

[Regina, Yori, Inthe, Risek, Aramis] is (J2, J3, J3, J4), takes 36 days and costs G$70,400. That is preferred over the 5-Jump route at a BVOT of only $665 per day, which includes all passengers who prefer the 5-Jump route over the 6-Jump route. The 5-Jump route is uneconomic, and the four-Jump route is preferred over the 6-Jump route by all passengers with a BVOT over G$1,080 per day.

[Regina, Treece, Risek, Aramis] is (J4, J4, J4), takes 26.5 days and costs G$91,200. It is preferred over the J-4 route by passengers with a BVOT over G$2,190 per day.

We conclude that there are only three economic services between Regina and Aramis.

• Passengers with a BVOT under G$1,080 per day prefer [Regina, Yori, Treece, Kinorb, Risek, hex 2911, Aramis] in a J2 liner transshipping at Risek to a J2+J2 liner.
• Passengers with a BVOT between G$1,080 per day and G$2,190 per day prefer [Regina, Yori, Inthe, Risek, Aramis]. J2 on the first leg, J4 on the last, transshipping twice.
• passengers with BVOT over G$2,190 per day prefer [Regina, Treece, Risek, Aramis] in a J-4 express liner.

G$1,080 per day is not a very high BVOT. The J4 service Aramis-Risek may be viable.

[thtraveller]

Interesting. I will analyze later.

Note: I added in the missing liners above:

$930 J2+1 Cargo liner

$5000 J2+J1 Passenger Liner
$6200 J3+J2 Passenger Liner
$34000 J6 Passenger Liner

[thtraveller]

Originally Posted by Agemegos

[Regina, Treece, Risek, Aramis] is (J4, J4, J4), takes 26.5 days and costs G$91,200. It is preferred over the J-4 route by passengers with a BVOT over G$2,190 per day.

You seem to be using around 9.2 days per jump (though I thought you were using 9.5), so shouldn't this be 27.6 days. And BVOT looks only to be around G$1540.

We conclude that there are only three economic services between Regina and Aramis.

• Passengers with a BVOT under G$1,080 per day prefer [Regina, Yori, Treece, Kinorb, Risek, hex 2911, Aramis] in a J2 liner transshipping at Risek to a J2+J2 liner.
• Passengers with a BVOT between G$1,080 per day and G$2,190 per day prefer [Regina, Yori, Inthe, Risek, Aramis]. J2 on the first leg, J4 on the last, transshipping twice.
• passengers with BVOT over G$2,190 per day prefer [Regina, Treece, Risek, Aramis] in a J-4 express liner.

G$1,080 per day is not a very high BVOT. The J4 service Aramis-Risek may be viable.

I think there is a fourth. I am quite liking a J2+J2 liner on that last route. Only G$57600 and 48.6 days. BVOT of G$1270 per day. Faster than the seven, and both six jump routes.

And with the BVOT spreads now close together at 1080, 1270 and 1540 I suspect that it collapses to the base route and the J2+J2 liner route - or maybe even just the cheap J2+J2 liner route. No transshipping, and the slightly slower pace gives the demand a chance to build between visits.

[Agemegos]

Originally Posted by thtraveller

You seem to be using around 9.2 days per jump

I'm using 9.5 days per Jump minus 2 days for passenger time, because I figure that passengers will not come aboard for initial loading or stay aboard for final unloading. But in the case of ships taking a double Jump I slice off another 2 days at each deep-space Jump because I reckon that it will not be necessary to cruise in from the 100D limit or to unload, load, and fuel between the Jumps.

And BVOT looks only to be around G$1540.

Sometimes I make arithmetic errors, especially when I don't do a formal plot. But in this case I think I had it right. Compared with the next slower economic option this saves 9.5 days at a cost of G$20,800, which is G$2,190 per day.

I think there is a fourth. I am quite liking a J2+J2 liner on that last route. Only G$57600 and 48.6 days. BVOT of G$1270 per day. Faster than the seven, and both six jump routes.

Six Jumps in a J2+J2 liner at 7 days each, with two port calls (at Treece and Risek) at 2.5 days each, half a day for each deep-space Jump, and half a day for the ends. That's 49 days on the basis I was using. Six Jumps at G$9,600 per Jump is G$57,600.

Compared with [Regina, Yori, Treece, Kinorb, Risek, (hex 2911), Aramis] (53 days, G$52,000) it is 4 days faster but $5,600 more expensive. It would be preferred at a BVOT of G$1,400 per day or above. Compared with [Regina, Yori, Inthe, Risek, Aramis] (36 days, G$70,400) it is 13 days slower but G$12,800 cheaper, so it is preferred at BVOT below G$984 per day. There are no BVOT values that are both below G$984 and above G$1,400, so all passengers prefer on of the alternatives and this service is not economic.

I figure that it has a narrow niche if the time between arriving and departing at a deep space Jump is short.

And with the BVOT spreads now close together at 1080, 1270 and 1540 I suspect that it collapses to the base route and the J2+J2 liner route - or maybe even just the cheap J2+J2 liner route. No transshipping, and the slightly slower pace gives the demand a chance to build between visits.

Well, demand building between visits is a double-edged sword, since it means that you lose a lot of passengers whose BVOT is high because they have to meet a deadline. (This is the problem of headway.) Express services need a short headway to be viable, because wait time for the service is a cost in time-critical applications, even if the wait time can be used productively.