Interstellar Shipping Question

[Vormaerin]

Imagine Trade in Traveller between Alpha Centauri and the Sol system. It's Jump 2 distance. You are on the Alpha Centauri world and you have significant volumes of goods for Terra/Luna, Mars, and Titan. And incidental goods for the various other locations in the Sol system. What is the most likely way this trade is managed for the large contract shipping routes? There is obviously going to be tramp trade, but the vast majority of the goods are going to be standard, scheduled routes.

Is it:
1) Three jump ships each loaded with the goods for their specific destination
2) One jump ship that goes to Terra/Luna and lets everyone else's goods get reshipped on non jump vessels based at the starport
3) Jump Tenders that regularly carry non jump freighters between the two systems and they go their separate ways from there?
4) Is the answer different for Mars and Titan, given how far Titan is from Earth compared to Mars?

Secondary questions
1) Does the answers above change depending on how far apart the different planets are at the time of transit? Mars can be anywhere from 50m and 400m km from Earth (farther, really, since you can't fly through the sun).
2) How important is it for a ship to be able to go directly to a Terran downport? Is that even legal or would customs/quarantine be at the highport?

Tertiary Questions
1) How far can you put a starport from a planet without the planet leaving it behind as it zooms around the solar system? Frex: can you put a refueling station at the 100D limit without it needing to be effectively just a tanker ship?
2) Micro jumping is so much more expensive than sublight travel that I don't think it would be used for commercial shipping (except for passenger vessels). Agree/Disagree?
3) Would LASh benefit from making the lighters into drone ships? Does that fit the Charted Space sensibilities?

 

[GabrielGABFonseca]

Right, I'm a bit pressed for time at the moment of writing so I'll rapidly address what my view on these are, and will probably make a post to clarify my points later (hopefully!):

I would say that the best way to do it is either 1) or 2), depending on what you're optimising for: 1) is the quickest method, but 2) offers the best price-per-ton. That's not to say 3) wouldn't work either, especially if a LASH infrastructure has been set up to support it.

Secondary Questions:
1) Yes, I'd say Jump Masking and the relative positions of the planets would very much affect this in a periodic manner.
2) I don't think it is important at all for a system as built up as Terra in the OTU; it has three different Highports to deal with its transit volume, after all.

Tertiary Questions:
1) That'll depend entirely on that planet's Hill Sphere radius, so it's a case-by-case thing.
2) Slightly disagree; if your priority is time above all else, microjumping will 100% be used for every flight where the week-long time in jump would be shorter than a sublight trip. Furthermore; I think that the 1000D limit for M-Drives introduced by T5 makes it so microjumping to outer system worlds is one of the fastest, safest ways to reach them. It's something I've long had on my backlog of things to investigate, but haven't as yet.
3) Eh. I guess? I can see Hivers and K'Kree doing that. In the Imperium they'd probably still use a Sophont for a pilot simply due to responsibility and legal accountability issues, methinks, but it really could be either way.

 

[NOLATrav]

Well, Tech Level is going to play a big part here. But my initial response is 2) one big ship that jumps to Terra/Luna and in-system vessels distribute the cargo/pax throughout the system. Smaller, mid-size ships and tramps could jump directly to their in-system destinations provided there is fuel/support for such vessels.

Secondary: no, distance doesn't matter, it's a solar system clockwork that's entirely predictable and sales/requests//supply/demand are going to be built around/settle in to these realities. Same with downports - by the time we're trading with Alpha Centauri a robust ecosystem of planetary and in-system shuttles will most definitely exist to facilitate rapid turnaround of jump vessels and there should be a fleet of faster shuttles available to mitigate aphelion distances, if that really even matters to the worlds in question.

Tertiary: The HG Update indicates that stations are capable of, well, station-keeping. I take that to mean they can orbit along with the world they serve. Agreed on micro-jumping but that's a case-by-case situation - tech level, primary star, destination location all play a part. The LASH thing with drones makes a lot of sense but the official Charted Space setting IMO is still calcified in the old ways of robots and drones existing but being way in the background. I'm personally ready to see drones and droids come more to the forefront (and they do IMTU) but there's a lot of history to unpack since we're going to be living in the 1105 era for the foreseeable future.

 

[Sigtrygg]

It has long been my contention that the 200t free trader is an insystem delivery van from inner system to outer system where it is faster to jump than to go at 6g.

 

[Vormaerin]

Historically, logistics has pretty much always optimized for price per ton. Shippers fairly recently experimented with faster ships, but quickly determined that practically no one wanted to pay for it. And it has other issues because ports have the same number of berths.

Jumping is vastly more expensive than straight shipping. Both because it reduces the cargo space on the vessel by a significant amount and because that fuel costs a lot of money. You would need clients willing to pay that premium instead of just planning over a longer scale.

A lot of the rest, imho, comes down to how cheap space infrastructure is. The primary bottleneck in shipping is the port. Slots at seaports and airports are prized IRL. If you have enough space infrastructure that slots and spaceport warehousing are not relevant, hub and spoke is probably the way to go.

 

[Condottiere]

Usually, it depends on what's being shipped, how much, and by whom.

Sol would be a special case, since by it's very history it's likely the third most developed system in human space; interesting question would be if you can leverage retrotech into a more cost effective transport system.

 

[AnotherDilbert]

Imagine Trade in Traveller between Alpha Centauri and the Sol system. It's Jump 2 distance. You are on the Alpha Centauri world and you have significant volumes of goods for Terra/Luna, Mars, and Titan. And incidental goods for the various other locations in the Sol system. What is the most likely way this trade is managed for the large contract shipping routes? There is obviously going to be tramp trade, but the vast majority of the goods are going to be standard, scheduled routes.

Is it:
1) Three jump ships each loaded with the goods for their specific destination
2) One jump ship that goes to Terra/Luna and lets everyone else's goods get reshipped on non jump vessels based at the starport
3) Jump Tenders that regularly carry non jump freighters between the two systems and they go their separate ways from there?
4) Is the answer different for Mars and Titan, given how far Titan is from Earth compared to Mars?

Titan is basically Jump-0 from Terra. If it's enough trade, send a ship directly.

Secondary questions
1) Does the answers above change depending on how far apart the different planets are at the time of transit? Mars can be anywhere from 50m and 400m km from Earth (farther, really, since you can't fly through the sun).

Mars probably depends on distance, from 1 day with a slowboat, to 5 days. At 5 days, it's basically a jump: If it's enough trade, send a ship directly.

2) How important is it for a ship to be able to go directly to a Terran downport? Is that even legal or would customs/quarantine be at the highport?

Why downport? The highport is faster and cheaper. Local transport can distribute the cargo cheaper. Pax can get to the actual destination faster with a local shuttle.

Tertiary Questions
1) How far can you put a starport from a planet without the planet leaving it behind as it zooms around the solar system? Frex: can you put a refueling station at the 100D limit without it needing to be effectively just a tanker ship?

As any other satellite; far enough.

2) Micro jumping is so much more expensive than sublight travel that I don't think it would be used for commercial shipping (except for passenger vessels). Agree/Disagree?

Disagree, it's not all that much more expensive. At longer distances more than 1 G would be used, except possibly for bulk cargo. Over 1 Gkm or so, just jump it, jump shadows permitting. Time-costs are significant.

In MgT J-1&M-1 costs about as much as M-3. Use what is faster, jump over ~2 Gkm.

3) Would LASh benefit from making the lighters into drone ships?

Somewhat cheaper, no biggie?

Does that fit the Charted Space sensibilities?

Sure, why not?
I wouldn't use it much, because of my prejudice about people in space, but that is my problem...

 

[Anstett]

I have a hunch that any system that has a spaceport has a large enough flow of traffic to have dedicated intra-system shipping Corps.

I agree that micro-jumps are a system by system judgement call based on the goods being transported. Just in Time raw materials for manufacturing would go by system boat, higher priced goods micro jumped by those with credits to burn.

Side thought:
How big would a system have to be to make sense to micro jump a message (physical mail obviously) to an outpost rather than deliver by system boat?

 

[Condottiere]

You don't jump if you don't have to.

While maintenance (costs) are somewhat of a joke in Traveller, there's wear and tear, and if you don't care about that, misjumps.

 

[Vormaerin]

My experience in shipping and logistics, while not some world class expert level, tells me that businesses don't pay for faster shipping when they can just order a week earlier in the schedule. This is borne out by experiments with faster sailing speeds by container shippers and how most businesses send goods ground or water even when much faster air freight is available. Businesses don't pay for speed unless they have no choice.

And micro jumps are massively more expensive than shipping by sublight vessel. First, inclusion of a jump drive by itself reduces the cargo capacity by 12.5% of the ship's volume between the engine and the fuel. Which means the cargo capacity of your freighter is 20 to 25% less (since freighters tend to be 50 to 60% cargo capacity unless very small hulls, which are worse). And then you are actually burning all that fuel. And that's ignoring possible increases in crew requirements (extra engineers because of larger engine size, an astrogator) that a starship has over a interplanetary vessel.

 

[Condottiere]

In that vein, delivery time would be more predictable.

 

[Vormaerin]

I have a hunch that any system that has a spaceport has a large enough flow of traffic to have dedicated intra-system shipping Corps.

I agree that micro-jumps are a system by system judgement call based on the goods being transported. Just in Time raw materials for manufacturing would go by system boat, higher priced goods micro jumped by those with credits to burn.

Side thought:
How big would a system have to be to make sense to micro jump a message (physical mail obviously) to an outpost rather than deliver by system boat?

Depends on how much people are willing to pay. If you have a 6G courier, you'd need a very large system (or some arbitrary realspace is screwed rule like the 1000d limit) to make micro jumps significantly faster, since you need to exceed 8 days travel time given the variability of jump. Even 1G is pretty competitive out to about Jupiter, depending on vagaries of relative rotation.

If you do use the 1000d limit rule, that's the answer right there. A 1000 solar diameters is where micro jumps take over. That's just shy of Saturn.

 

[Vormaerin]

Why downport? The highport is faster and cheaper. Local transport can distribute the cargo cheaper. Pax can get to the actual destination faster with a local shuttle.

Why is it faster and cheaper to have a highport with a large berth for a megafreighter and the infrastructure to transfer all the cargo to other ships to send down to the planet rather than have a collection of smaller freighters going directly to the downport? What am I missing? Small craft cargo shuttles are not cheaper than Big Craft cargo freighters per ton of cargo.

Obviously, with 2300 style interface issues for earth to orbit shipping, that's a different paradigm. But in Traveller, the time from orbit to surface is not significant compared to the distance from Orbit to Jump Point. So it doesn't seem like it would be appreciably cheaper to dock at the highport rather than have the lighters go straight to Phoenix Downport or whatever.

 

[Sigtrygg]

Back to the question where to put the highport for Earth.

You place it in orbit around the sun in the same orbit as the Earth at 100D from the Earth.

 

[Condottiere]

I'd Swiss cheese the Moon.

 

[Vormaerin]

Back to the question where to put the highport for Earth.

You place it in orbit around the sun in the same orbit as the Earth at 100D from the Earth.

lol. Didn't think of that. Seems obvious in retrospect. We've already put some things in heliocentric orbit, so of course a starport could be.

 

[MasterGwydion]

lol. Didn't think of that. Seems obvious in retrospect. We've already put some things in heliocentric orbit, so of course a starport could be.

LeGrange Points

 

[Vormaerin]

Yes, I know about LaGrange points. I don't think those actually serve the purpose that I was interested in.

I wanted to know whether it was possible to put a space station around the 99 to 100 planetary diameters and have it stay on station without needing to have a full on maneuver drive (ie be a regular ship). I don't think the L4 or L5 points are actually close to that distance.

 

[Anstett]

From the Starports book:
"A Highport is a space station, maintaining a geo-synchronous orbit above a Downport. In essence, it is a spaceship that tends not to move – though it does, indeed, have a limited capacity to do so."

In none of the examples does it have the description of an M drive, and it is not one of the Upgrade modules listed. The book does cover mostly Downport construction with notes on additional requirements for Highports.


Highguard 22 does list this for Space Stations:
Stations without a manoeuvre drive must be adjusted manually by a tug or other suitable spacecraft.

 

[AndrewW]

Highguard 22 does list this for Space Stations:
Stations without a manoeuvre drive must be adjusted manually by a tug or other suitable spacecraft.

Note Manoeuvre-0 was specifically put into the 2nd edition High Guard with station keeping for space stations in mind.