5 parsec gap in trade route

[aramis]

Call me simple, but I'd run the numbers on a J1x5 ship with 40+ ton fuel bladders installed in the cargo bay at one end of the gap and removed at the other end (for installation on ships heading the other way).
[or a J2x3 ship if the main is not J1 outside the gap].

I suspect that I'd eat eat their (J3 or J5) lunch on the cargo trade.

They'd lose out due to (1) storage cost at the ends of the J5 section (2) 1.67j3 is KCr10 per ton cheaper than 1J5 already - the bladder increases costs further, not reduces it, as it's more hardware to amortize out; (3) The J5 drive is MCr8 per hundred tons of hull more expensive itself than the J3 drive, which has to be amortized into the cargo tonnage.

The line's cheapest bet is a dedicated 1.67J3 hauler for that one link, and J2 everywhere else, presuming either CT Bk5 or Bk2 designs.

 

[Selandia]

The original question stated "The route is being used by only one company, so the company fleet can be tailored to the route". Being able to carry 2X or 3x the cargo in a single jump probably makes the extra cost of ships and tugs worth it fairly quickly. I'm sure even with MgT ships it would be well worth it. However it's a game and the GM can justify whatever rules he wants to suit his needs. I just though I'd mention it

yes, I was just marking that we were using the same assumption as to the commercial background although I never computed in MGT terms.

Selandia

 

[Amber Chancer]

Have you considered having J-3 transport ships work in conjunction with auxiliary fuel tenders?

The fuel tenders are Jump-1 ships with 20% own jump fuel tankage (i.e. enough to make two 1-parsec jumps: out and back), enough payload fuel tankage to replenish the transports from a Jump-1 (or fuel it up for a Jump-1) and a fuel refining plant able to refine it all. You will need two of them in service at any one time; one jumps with the transport to a Jump-1 destination in deep space, refuels it, and then jumps back to the world of origin to replenish its tanks while the transport makes its Jump-3 to a deep space location 1 parsec from the destination world, where it is met by the second fuel tanker which has jumped out from the destination world to make the rendezvous.

This is MUCH cheaper than building and manning refuelling stations in deep space; and it also obeys the fundamental commercial principle of not handling something (in this case teh fuel) twice, when you can arrange to handle it only once.

A rigid schedule needs to be planned and observed, of course, because the safety of the transport ship and all aboard depends upon those fuel tankers keeping the rendezvous with the incoming ship; and it might be that the most sensible design for the tanker ships is one which actually carries enough payload fuel to refuel both the outgoing AND the incoming ship - although that depends upon the frequency of service you are aiming to maintain.

Deep space fuelling stations make sense for Navy operations, where you cannot predict the frequency or the quantity of the demand for fuel and need simply to sprovide a stickpile sufficient to cover all likely scenarios (a bit like LRDG fuel dumps in the Desert War ...) but for commercial operations, you may as well refuel directly from the ship which jumps the fuel out there as maintain a deep space station and transfer the fuel from ship to station and then from station to ship again. Commercial organisatiosn woudl always look to cut out the middle man ...

 

[BytePro]

I'm sure it depends somewhat on ruleset. Not sure on how the costs really work out, but if TL is a limit, CT HG would require TL-E for J-5 ships - so I would probably handle it using fuel Tankers hauling fuel to a deep space fuel depot.

Then TL limit might be a further determiner. I.e. using CT HG2 rules and seat of the pants figur'n -

Ignoring M-Drive fuel...

TL-C (min for J3):
A 10x dton Tanker ship could support around 10 2-way trader runs per drop... Example:

10,000 dton J2 Tanker with fuel for its own outbound/return run should have room for ~3,000+ tons for depot

Fully fueled 1,000 dton J3 Trader can do J2 initial leg - with 100 tons left
Needs 200 dtons from deep space fuel depot to complete outbound run
Refuels at dest and does J3 on return run...
Needs 300 tons from depot for final return leg
​

TL-D (min for J4):
A J-4 trader will reduce the depot refueling ~ half and increase the fuel deliverable - supporting ~ two dozen trader runs, albeit at the expense of reducing an already rather limited cargo volume (~20%?)...

10,000 dton J1 Tanker drops off 5,000+ dtons fuel

Fully fueled 1,000 dton J4 does J1 initial leg - with 300 dtons left
Needs 100 dtons for J4 final outbound
Refuels at dest for J4 and does J4 on initial return leg
Needs only 100 dtons for final J1​

 

[Carlobrand]

They'd lose out due to (1) storage cost at the ends of the J5 section (2) 1.67j3 is KCr10 per ton cheaper than 1J5 already - the bladder increases costs further, not reduces it, as it's more hardware to amortize out; (3) The J5 drive is MCr8 per hundred tons of hull more expensive itself than the J3 drive, which has to be amortized into the cargo tonnage.

The line's cheapest bet is a dedicated 1.67J3 hauler for that one link, and J2 everywhere else, presuming either CT Bk5 or Bk2 designs.

Does that factor in the fact that the J5 can make more runs in the same period of time, or is the J5 too pricey to turn a profit even with that?

 

[aramis]

Does that factor in the fact that the J5 can make more runs in the same period of time, or is the J5 too pricey to turn a profit even with that?

The J5 is amortizing over 2 weeks instead of 3, assuming the standard turn around schedule of week in system between jumps. But that's accounted for in figuring the costs. Yes, it's cheaper to go by J3+J2 rather than 1j5, because (ignoring the canonical prices of cargo space), the cost to operate 1J5 is STILL higher per jump per ton due to more drive tonnage, and thus higher PP tonnage as well. Note that for the 1000Td, that's MCr80 extra for the JD, MCr120 extra for the PP, and MCr27 extra for the computer, adding 20, 40 and 2 Td respectively. And hits just shy of an extra engineer needed.

302 tons cargo 1.333x per month (Total 402) instead of 220 tons twice a month, for 440 per month, but less cost for the ship. 2/3 the cost for 8/9 the cargo per month... long term, the TL14 solution is going to be the J3 for everything but fresh produce. And then, much fresh produce really isn't very fresh after the 8-10 day shipment.

(As a kid, veggies and fruit typically took 8-12 days to ship to Alaska, and were nasty and unpalatable. Mostly, it was going overland a couple days to a major port, then into San Francisco or LA, then up to Seattle, then on to Alaska, changing boats each time. Air freight was still too expensive for veggies at that point. Once they started with the 3-4 day air freight, tho, the veggies and fruit got MUCH better. We ate a lot of cabbage, lettuce, carrots, potatoes, and pickled veggies in my childhood - canned stuff shipped well, and the others were grown locally.)

 

[HG_B]

A lot of this depends on what is being carried (the OP said that the route is used by one concern only) as cargo. Cost per ton is interesting but, how does that effect the unit price of the goods? Let's say that you are carrying Cr100 iPads. How many per ton? LOTS! Let's say 1000/ton.

Figure the difference in freight rate/ton you'd have to charge going from J3 to J5 and apply the difference to the unit cost of the CR/100 iPad. It would hardly be a noticeable difference...

 

[far-trader]

... Let's say that you are carrying Cr100 iPads. How many per ton? LOTS! Let's say 1000/ton.

Actually it probably depends on the rules edition. In CT "how many iPads per ton" is simple, but you've not provided the correct information to determine it.

What is the base price per ton of iPads? And how much does each one weigh?

Let's say they are 0.1kg (including accessories and packaging) each. In CT (per example bottom of pg 48 LBB2) a ton of cargo is 1000kg so you have 10,000 iPads in a 1ton crate. If you set the base value at Cr100 per iPad then that 1ton crate has a base value of MCr1.0 for speculative trade purposes.

Other rules editions may operate differently.

 

[HG_B]

Let's say they are 0.1kg (including accessories and packaging) each. In CT (per example bottom of pg 48 LBB2) a ton of cargo is 1000kg so you have 10,000 iPads in a 1ton crate. If you set the base value at Cr100 per iPad then that 1ton crate has a base value of MCr1.0 for speculative trade purposes.

Correct. So in the OP's example problem, they'd probably go for J5 as they, for some reason, have a monopoly on that route. But, can't say for sure without knowing what the business actually is.

The rules edition has nothing to do with how many ipads fit in X amount of volume. (unless you're talking about Dton volume differences between edition. )

 

[BytePro]

I'm sure he's dragging in the messed up CT trade rules which confuse volume with weight (and notably end with a flat out example of such).

Of course, mass is irrelevant in the DTon gravitics based system - and using 'weight' is pretty lame in the sci-fi setting to boot (and further indication the the author/editor of such was less than adequate at the task).

Ignoring that one paragraph - assuming that shotguns, with packing, are 1/200 Dtons, fixes the screw up nicely and using DTons instead of tons works better for CT. Its not the only example to be screwed up, though the whole 3 half size pages of 'Trade and Commerce' probably could have used a decent re-write - and Merchant Prince notably lacks this example (though it does nothing to clear up the issue - using 'per ton' without clarifying dtons).

I'm sure endless debates have raged over this topic...

 

[HG_B]

I'm sure he's dragging in the messed up CT trade rules which confuse volume with weight (and notably end with a flat out example of such).

Of course, mass is irrelevant in the DTon gravitics based system - and using 'weight' is pretty lame in the sci-fi setting to boot (and further indication the the author/editor of such was less than adequate at the task).

I had forgotten about that. But, in any event, if you're not hauling low grade dirt that costs a CR per ton (volume), the added cost per ton for freight using a J5 ship, even if added to the merchandise (iPads in this example) sale price, isn't going to increase the price of an individual item enough to really matter.

If it costs CR3,00 more per dton of freight to make the J5 ship financially viable over a J3; that would only add up to Cr3 more for each iPad (if they are 1,000 in a dton.) But, then we're using logic. Something Trav interstellar commerce rules have never excelled at.

 

[rancke]

One way the cargo is whatever valuables can be extracted from a captive group of several million TL4 people and the other way it is the goods to supply 700 people plus whatever mercenaries is needed to perform the aforementioned valuables extraction. (Plus carrying the mercenaries to and from the captive world).


Hans

 

[atpollard]

They'd lose out due to (1) storage cost at the ends of the J5 section (2) 1.67j3 is KCr10 per ton cheaper than 1J5 already - the bladder increases costs further, not reduces it, as it's more hardware to amortize out; (3) The J5 drive is MCr8 per hundred tons of hull more expensive itself than the J3 drive, which has to be amortized into the cargo tonnage.

The line's cheapest bet is a dedicated 1.67J3 hauler for that one link, and J2 everywhere else, presuming either CT Bk5 or Bk2 designs.

It took me some time to figure out what "1.67J3" means [Jump 3 drive with 50% of the ship as Jump fuel ... enough for a Jump 3 and a Jump 2 before refueling.]

I think that you misunderstood my notation as well ... I was suggesting a Jump 1 ship with 10% jump fuel and renting a balloon to convert 40% of the ship (normally cargo hold) to temporary fuel storage to allow five consecutive Jump 1. The bladders would be rented out by the high ports at either end of the J5 gap and each bladder would simply travel back and forth across the gap in a different ship each time.

In effect, the ship transports extra fuel as cargo. Since a Jump 1 ship costs less and carries more cargo than either a Jump 3 or Jump 5 ship, it may be more economical to operate. I am speculating that the annual rental cost of the fuel container will be less than the annual cost of maintaining a special J5 fleet. It will also allow anyone to cross the gap rather than restricting the region to operating separate fleets trapped on either side of the gap and a third fleet that only jumps the gap.

Obviously, if the rest of the route requires a Jump 2 ship, then the scenario becomes ... a Jump 2 ship with 20% jump fuel and renting a balloon to convert 30% of the ship (normally cargo hold) to temporary fuel storage to allow two consecutive Jump 2 and a Jump 1.

Either way, crossing the gap uses normal ships renting fuel balloons from the highports to transport extra fuel as cargo - with the balloons travelling back and forth between the highports.

[As an aside, if ships typically have purifiers, then the extra fuel can be shipped as water.]

[EDIT: One last point, a dedicated J5 or J3 fleet requires a TL 14+ or TL 12+ Class A starport for maintenance at one end of the gap ... or a larger fleet to accommodate long down times for travel to/from the distant maintenance port. My plan could work with TL 6+ highports at the gap and J1 or J2 ships getting annual maintenance anywhere along the trade route that they normally would.]

 

[rancke]

In effect, the ship transports extra fuel as cargo. Since a Jump 1 ship costs less and carries more cargo than either a Jump 3 or Jump 5 ship, it may be more economical to operate.

It's not. In the time it takes a jump-1 ship to move a load of cargo three parsecs (three jumps), a jump-3 ship moves three loads of cargo the same distance. The individual loads are smaller, but large enough to offset the higher cost. The cargo space of jump-5 ships is so much smaller than that of jump-3 ships that moving its cargo 67% farther per jump is nowhere near enough to compensate for the increased cost of the ship.

What I was unable to figure out was whether having to reduce cargo space by 20 percentage points would make jump-3 less economic than jump-5. Wil dealt with that in an earlier post. According to his figures it does not.


Hans

 

[atpollard]

It's not. In the time it takes a jump-1 ship to move a load of cargo three parsecs (three jumps), a jump-3 ship moves three loads of cargo the same distance.

In this specific comparison, you are correct.

In practice, the next desirable world along a typical route could be 1, 2 or 3 parsecs away. So what happens when a J1, a J2 and a J3 ship all leave World A and travel 1 parsec to World B, then travel 3 parsecs to World C and then travel 2 parsecs to World D?

Ship J3 completes the route in the shortest time (about 6 weeks by standard reckoning), but suffers increased ship cost and reduced cargo for two of the three jumps.

Ship J2 completes the route in the a little more time (about 7 weeks by standard reckoning), but suffers increased ship cost and reduced cargo for some of the four jumps.

Ship J1 completes the route slowly (about 9 weeks by standard reckoning), but but has the lowest ship cost and highest cargo capacity.

I could run all of the numbers, but the results would apply to this sequence of jumps only ... another sequence will yield different results. My point is simply that the reality over the 50 week annual life of a typical trader will probably not be best represented by comparing a single J3 link to three J1 across the same link. The real issue is for a J1, J2 or J3 ship plying a given trade route, how many jumps will be less than optimal (1 parsec in a J3 ship) and how many will be optimal (2 parsec in a J2 ship) and which ship is best across the full range of the trade route.

I do not question your or Aramis' specific calculations as much as I find the focus of the analysis too narrow to automatically reflect the 'best' solution for the economy of a larger region. So I offer an alternative option for consideration.

If only two Jumps in 50 weeks of operation are J3 with an otherwise equal mix of J1 and J2, then suffering a loss in efficiency for three J2 rather than two J3 might be more economical over the long run.

 

[rancke]

In practice, the next desirable world along a typical route could be 1, 2 or 3 parsecs away. So what happens when a J1, a J2 and a J3 ship all leave World A and travel 1 parsec to World B, then travel 3 parsecs to World C and then travel 2 parsecs to World D?

They don't. The J1 ship establishes a service back and forth between A and B, the J3 ship establishes a service back and forth between B and C, and the J2 ship establishes a service back and forth between C and D.

Ship J3 completes the route in the shortest time (about 6 weeks by standard reckoning), but suffers increased ship cost and reduced cargo for two of the three jumps.

So why would it do the two sub-optimal jumps at all?

Ship J2 completes the route in the a little more time (about 7 weeks by standard reckoning), but suffers increased ship cost and reduced cargo for some of the four jumps.

So why do the sub-optimal jumps at all?

I could run all of the numbers, but the results would apply to this sequence of jumps only ... another sequence will yield different results.

Sure, the route is a crucial factor. Which is why the J3 ship won't start at A, won't jump short to B (unless someone is willing to pay enough to make it worth its while, which will only happen if there are no J1 and J2 competition between A and B), and won't go on from C to D (same caveat).

My point is simply that the reality over the 50 week annual life of a typical trader will probably not be best represented by comparing a single J3 link to three J1 across the same link. The real issue is for a J1, J2 or J3 ship plying a given trade route, how many jumps will be less than optimal (1 parsec in a J3 ship) and how many will be optimal (2 parsec in a J2 ship) and which ship is best across the full range of the trade route.

What do you think of when you say "a typical trader"? Because I'm talking about a regular freight service that makes its money by hauling freight. The "given trade route" for any given ship is the one that optimizes its operation. J3 ships hauling freight from A to D will have no reason to visit B and C; contrariwise, if they do have reason to visit B and C along the way, someone is paying them more than a J1 or J2 ship would charge for the same service.

(Your example does assume the existence of fuel sources in every intermediate hex, right? Because if not, the J1 and J2 ships lose a lot of their effective cargo space).

I do not question your or Aramis' specific calculations as much as I find the focus of the analysis too narrow to automatically reflect the 'best' solution for the economy of a larger region. So I offer an alternative option for consideration.

Sure, special considerations can change what is only a crude approximation in the first place. But what special considerations apply here?


Hans

 

[atpollard]

They don't. The J1 ship establishes a service back and forth between A and B, the J3 ship establishes a service back and forth between B and C, and the J2 ship establishes a service back and forth between C and D.

They do.
All real world Panamax container ships with a 3000 mile range do not ply a single route between two ports exactly 3000 miles apart ... back and forth ... to the exclusion of all other destinations. The ship might indeed deliver goods to a port only 2000 miles away.

Within Traveller, the Subsidized Merchant is a freight ship that clearly follows a multi-world route. Only one world along this route requires a class A starport for annual maintenance.

What source indicates a plethora of freighters travelling exclusively back and forth between the same two worlds? One of these worlds will need a Class A starport for maintenance or many ships will suffer a long period of no revenue while it ferries to and from a distant maintenance port (under your assumptions).

In fact, your assumptions render the terms "trade route" and "J1 Main" or "J2 Main" almost meaningless. There are no "routes" or "mains". There are only unrelated links in an infinite web ... with gaps wherever an unprofitable link between two worlds exists.

[EDIT: Ignore the above ... I was going to delete it, but I think that my question has some merit, so I left it.

... Back to square one:
You set up an initial question assuming that the only choices were between a single J5 or a multiple jump J3 ship. Your question was answered by others.

I felt (and still feel) that you have excluded other possibilities that have merit. As your world, that is your right. I don't want to argue the minutiae any further and don't have the time or interest to lay out a stronger economic case using detailed designs and cost estimates. Sorry to have wasted your time, I was only suggesting other alternatives.]

 

[rancke]

All real world Panamax container ships with a 3000 mile range do not ply a single route between two ports exactly 3000 miles apart ... back and forth ... to the exclusion of all other destinations. The ship might indeed deliver goods to a port only 2000 miles away.

Real world ships don't employ jump drives nor any form of travel remotely aznalogous to jump drive.

Within Traveller, the Subsidized Merchant is a freight ship that clearly follows a multi-world route. Only one world along this route requires a class A starport for annual maintenance.

It's also an outlier situation. Someone is, in fact, paying the ship to ply a sub-optimal route. That's what 'subsidy' means.

What source indicates a plethora of freighters travelling exclusively back and forth between the same two worlds? One of these worlds will need a Class A starport for maintenance or many ships will suffer a long period of no revenue while it ferries to and from a distant maintenance port (under your assumptions).

Only in outlier situations. If there is enough freight to support a decent number of ships, someone will establish a maintenance facility. Realistic economics don't work by randomly establishing that there isn't such a facility around and then scrambling to explain why. The way it works is that if there is enough of a need to make it profitable, someone will come along and supply that need.

Also, a Class C starport classification simply means that no one is building spaceboats or starships. A starport with a ship maintenance facility that didn't build things would not qualify for a Class B or A rating.

In fact, your assumptions render the terms "trade route" and "J1 Main" or "J2 Main" almost meaningless.

It does indeed. The problem is that my assumptions are logical ramifications of the ways ships are built and operated.

There are no "routes" or "mains". There are only unrelated links in an infinite web ... with gaps wherever an unprofitable link between two worlds exists.

I don't understand how you arrive at that conclusion. A link in a profitable chain between two worlds need no be profitable in itself.


Hans

 

[rancke]

You set up an initial question assuming that the only choices were between a single J5 or a multiple jump J3 ship. Your question was answered by others.

I felt (and still feel) that you have excluded other possibilities that have merit. As your world, that is your right. I don't want to argue the minutiae any further and don't have the time or interest to lay out a stronger economic case using detailed designs and cost estimates. Sorry to have wasted your time, I was only suggesting other alternatives.]

Sorry, I thought you were asking a general question arising from but irrelevant to the original issue.


Hans

 

[DangerousThing]

They don't. The J1 ship establishes a service back and forth between A and B, the J3 ship establishes a service back and forth between B and C, and the J2 ship establishes a service back and forth between C and D.

If the three ships work together, yes, that would be optimal.

Generally Traveller small trading ships are the equiilent of tramp traders. They buy a lot of their own speculative cargo and take freight to fill the rest of the space.

These are ships run by a bunch of retired guys who both want to make the mortgage and go fishing. Probably both items determine the route.

The large companies have the big ships that are on a solid route. They handle most of the freight and passengers. What's left is what the type As and other tramps get.