Sector Data (economic)

[tjoneslo]

I've been thinking about this and how it might be "improved". After running all of the calculations, when it begins drawing the trade routes instead of considering Charted Space as a whole from the start, it might make sense to work up in geographical size, ie. subsector, sector, (domain), (larger), Charted Space. You'd still begin with the highest BTN at each stage. The downside is that it would take quite a bit longer to process.

Mostly this is a sorting order problem, and not a huge time sink in the overall timing of the process.

However, the subsector/sector borders are entirely arbitrary. In working on another Traveller setting book I started looking at using circular (well hex shaped) "subsectors". No longer tied to the size and shape of a digest sized book, I have some interesting looking empires and a new view of how the worlds relate to each other.

Combining these I think what should be done is:
Start with the largest WTN worlds. For each draw the routes to every world within a short distance (jump 4 to 6) , in the BTN order as before. Then go back through the worlds again and do a medium distance (jump 12 to 24), again in BTN order. And then do the rest of the long distance routes. This would get the "local" routes more apparent driven by the large, industrial worlds, and delegate the long distance routes to following the local ones as the primary routes.

 

[TamsinP]

Looking in more detail at trade within Aramis subsector (not including trade beyond the subsector), which was my original project, using the canonical routes in The Traveller Adventure for the different shipping lines there probably would be enough trade for Akerut to justify having a fleet of about 50 Hercules class freighters... if Oberlindes Lines and Imperiallines weren't also operating in the subsector. As things stand, it looks very much like they need to change their fleet composition up - J1 5k dTon hulks are fine for the Towers Cluster, but elsewhere they are almost certainly losing out to the smaller J2 and J3 capable ships of their competitors. The sensible solution would be to replace them with second-hand J4 3k dTon Prosperity class freighters from the Tukera fleet and maybe some Type RT liners with part of their passenger space converted to cargo holds for lower-volume routes (removing de-mountable fuel tanks as appropriate for the route to increase available cargo space). Some of the remaining Hercules freighters could be upgraded to J2 for the high volume Junidy/Aramanx route

Another "d'oh!" moment - I'd forgotten to take into account the fact that the Hercules freighters would be making a series of 1-parsec jumps for the routes which means that you need more ships to transport the same volume of cargo over the same distance each year. Assuming each ship can make 40 jumps per year and taking into account the reduced cargo volume for ships with de-mountable fuel tanks fitted for J2 and J3 legs (which might be pushing it a bit) there is enough freight to fill the holds of 130-140 Hercules freighters. That is based on the shortest routes; if they follow the routes show in The Traveller Adventure, it would be more.

An interesting tidbit from my analysis is that Focaline only generates enough freight each year to fill one Hercules (with extra fuel tanks fitted for the 3-parsec jump to Zila following the "canon" route. That fits with the lore that the system's main export is groat meat and skins/fibres, suggesting an annual shearing and culling.

 

[Spinward Flow]

Assuming each ship can make 40 jumps per year and taking into account the reduced cargo volume for ships with de-mountable fuel tanks fitted for J2 and J3 legs (which might be pushing it a bit)

At that scale, you're better off using collapsible fuel tanks. A Hercules class cargo transport has a 5000 ton J1 ship, so jump fuel is 500 tons per parsec. So a collapsible fuel tank will occupy 5 tons of cargo space when not loaded with any fuel.

If your route requires 2 parsecs of range, you need one 5 ton collapsible fuel tank (5 tons empty, 500 tons full).
If your route requires 3 parsecs of range, you need two 5 ton collapsible fuel tanks (10 tons empty, 1000 tons full).

The advantage that using collapsible fuel tanks brings is that you do not need to load/unload/warehouse demountable fuel tanks, which can take weeks to install/remove ... so collapsible fuel tanks offer "quicker flexibility" while en route.

Also, 40 jumps per year is TOO MUCH.

Assume 8 days per jump (175 hours + 16 hours = 191 hours maximum = 8 days) and 5-6 days of normal space (maneuver to/from jump points, cargo loading/unloading at starport) and you get the following:

• J1 = 6+8=14 * 25 = 350 days + 14 days annual overhaul maintenance = 364 days @ 25 jumps per year
• J1+1 = 6+8+8=22 * 16 = 352 days + 14 days annual overhaul maintenance = 366 days @ 32 jumps per year
• J1+1+1 = 5+8+8+8=29 * 12 = 348 days + 14 days annual overhaul maintenance = 362 days @ 36 jumps per year

That means, the range of a Hercules in a single year is:

• 25J1 = 25 parsecs
• 16J1+1 = 32 parsecs
• 12J1+1+1 = 36 parsecs

 

[mike wightman]

Which is why big shipping corporations should have jump ships jumping and in-system haulers moving the cargo from jump point to world.
That way you big expensive jump ship can jump more often.

 

[TamsinP]

At that scale, you're better off using collapsible fuel tanks. A Hercules class cargo transport has a 5000 ton J1 ship, so jump fuel is 500 tons per parsec. So a collapsible fuel tank will occupy 5 tons of cargo space when not loaded with any fuel.

If your route requires 2 parsecs of range, you need one 5 ton collapsible fuel tank (5 tons empty, 500 tons full).
If your route requires 3 parsecs of range, you need two 5 ton collapsible fuel tanks (10 tons empty, 1000 tons full).

The advantage that using collapsible fuel tanks brings is that you do not need to load/unload/warehouse demountable fuel tanks, which can take weeks to install/remove ... so collapsible fuel tanks offer "quicker flexibility" while en route.

Also, 40 jumps per year is TOO MUCH.

Assume 8 days per jump (175 hours + 16 hours = 191 hours maximum = 8 days) and 5-6 days of normal space (maneuver to/from jump points, cargo loading/unloading at starport) and you get the following:

• J1 = 6+8=14 * 25 = 350 days + 14 days annual overhaul maintenance = 364 days @ 25 jumps per year
• J1+1 = 6+8+8=22 * 16 = 352 days + 14 days annual overhaul maintenance = 366 days @ 32 jumps per year
• J1+1+1 = 5+8+8+8=29 * 12 = 348 days + 14 days annual overhaul maintenance = 362 days @ 36 jumps per year

That means, the range of a Hercules in a single year is:

• 25J1 = 25 parsecs
• 16J1+1 = 32 parsecs
• 12J1+1+1 = 36 parsecs

I agree that 40 parsecs/year is pushing the ships (and crews!) very hard. Dropping to 25 jumps/year takes the total up to about 220.

On the basis of 25 jumps/year, for the J2 and J3 routes only a few ships are actually needed - 9 and 12 respectively. In reality, there isn't enough freight from Lablon to Corfu to warrant a J2 ship permanently assigned so it would make sense for the J3s to carry on. That puts the numbers to 8 and 13.
I see the J2 and J3 ships having the extra tanks "permanently" fitted and they just keep plying the same route. The J2 ships would mostly be at Pysadi, with a one or two at Paya/Violante; for the J3 ships, 6 would be at Lablon, the other 7 at Aramanx.

 

[Spinward Flow]

Which is why big shipping corporations should have jump ships jumping and in-system haulers moving the cargo from jump point to world.
That way you big expensive jump ship can jump more often.

There's a problem with that assumption.
Does EVERYONE break out of jump at EXACTLY the same location EVERY SINGLE TIME without fail?

Is there like a teeny tiny volume of sky where every single incoming jump yields a jump flash THERE and ONLY THERE?
Common sense dictates that the answer to that question is: NO ... not even by a long shot.

Starships can (and will!) break out of jump anywhere along the surface area of a 100D jump shadow ... which can be for a star, or it can be for a planet ... or they can break out of jump anywhere BEYOND the 100D jump shadow radius (just not within one). Depending on the precision of the astrogation skills and compute power/jump drive tuning, the variance upon breakout from jump can be THOUSANDS (if not MILLIONS!) of kilometers in two (or even three!) dimensions.

"Flying through hyperspace ain't like dustin' crops, boy!"

My point being that the notion of there being a "dedicated arrival zone" for incoming starships, where they only break out of jump within a very limited volume of space (so don't bother with looking, let alone going, anywhere else!) is just bonkers. Starships can break out of jump anywhere on a HEMISPHERE of the jump shadow that faces the system of origin the starship jumped from. If the planet you're trying to get to is "on the wrong side of the local star" from the system of origin, you can hit the star's jump shadow and then need to maneuver all the way around the star to get to the planet on the "far side" of the star's jump shadow(!). And because all the planets are orbiting their stars, everything is always in motion ... so just because you were able to achieve a "perfect" breakout location from jump, exactly where you wanted to be, THIS TIME is no guarantee that you'll be able to pull off the same trick reliably in the future ... or that other ships with other crews will be able to accomplish the same feat (even once, let alone repeatedly and reliably).

To put it politely, jump drives aren't necessarily THAT accurate AND precise ... every single time, without fail. They'll get you to a target star system just fine, but asking a jump drive to break out "on a dime" with extreme accuracy and precision is a bit of a mug's game.

Jump drive is more of a "horseshoes and hand grenades" type of game, with regards to breaking out of jump where you want to be. Navigator skill can stack the odds in your favor, but precision down to the 1 kilometer CEP (circular error probable) is undoubtedly a foolish assumption when jumping across interstellar distances.

 

[aramis]

Jump accuracy is, IIRC, 1000km/pc
Time accuracy is + or - 16.6 hours... which can be a considerable change in distance relative to jump accuracy.

 

[Condottiere]

It's also a moving target.

 

[tjoneslo]

There are also LASH (lighter aboard ship) where you have several or many small cargo carriers with their own M-Drive. Having the cargo with its own M-Drive makes loading and unloading much quicker. Where ever the ship comes out of jump space is a relatively small volume of space compared to the rest of the system. So a couple of hours to roll the lighters off, and attach new ones and do a fueling operation should be possible.

 

[Spinward Flow]

where you have several or many small cargo carriers with their own M-Drive.

Those aren't (breakbulk) cargo containers.
We call those Small Craft.

See Modular Cutter and Modular Cutter Module for reference.

Now, if you're saying that you can put a Modular Cutter (or few) onboard a much larger starship for "shuttle services" and just have Lots And Lots™ of Modular Cutter Modules that all the cargo gets stuffed into for transport ... that's perfectly valid.

Saying that just "any ol' cargo lot in the hold" is capable of "flying off on its own and delivering itself to a starport" without the assistance of some kind of Small Craft ... IS NOT.

If you want M-Drive performance shifting cargo (in space!), you need to pay for hull, drives, controls, flight crew ... need I go on?

 

[aramis]

It's also a moving target.

A target movement which can be predicted to below the accuracy of the position.

 

[aramis]

Those aren't (breakbulk) cargo containers.

Roll On/Roll Off (RO/RO), however, is a common mode even now. Daily use in many places.... (Many ferries are RO/RO for local distribution from a nearby container-capable port)

The appropriate term for that when using proper vehicles aboard is "Lighter Aboard SHip" - it's inefficient, due to extra drives, but for in system haulers between GG subsystems, Big carrier, long term life support, for the between subsystems, short term only for within. If the lighters are a standard form factor, a colonial mission can easily use the LASH model to allow private lighters and charged transit between the major clusters. This alows a good level of multi-day inter-moon trips in seats, but the week-plus inter GG/MW trips you dock, take advantage of staterooms (possibly at reduced tonnage on the carrier, with sleeping in lighter couches), and have the social experience of a liner.

 

[Condottiere]

I remember when I first came across that term, in Red Storm Rising.

So very suited for expeditionary forces.

Roll On Roll Off could be done with grav motivated vehicles in low orbit.

 

[Spinward Flow]

Roll On Roll Off could be done with grav motivated vehicles in low orbit.

True.
However, it's "a bit of a walk" from low orbit out to a jump point, so there's going to need to be "maneuvering" for a bit before any unloading/loading of starships can happen.

 

[Condottiere]

On the upside, you don't need large infrastructure to dock the spacecraft, and if you are allowed to move, you could drift closer to multiple delivery points.

 

[kilemall]

On the upside, you don't need large infrastructure to dock the spacecraft, and if you are allowed to move, you could drift closer to multiple delivery points.

Going to limit you to A/B/C starports though, right? Which isn’t a bad business/ship design thing for more settled areas.

 

[Condottiere]

There are a lot of holes in respective system descriptions, so in a lot of cases it's up to the dungeon master to invent details.

It's possible, as in the above video, a lot of transhipment is going on in the Spinward Marches.

In the end, it's hard to be definitive, because even if you have a Starport/Alpha, it might just have the minimum requirements to be labelled as such, and can't handle megafreighters, or at least, not efficiently.

 

[Condottiere]

Going to limit you to A/B/C starports though, right? Which isn’t a bad business/ship design thing for more settled areas.

Probably the opposite, since you're practically acting as a floating dock.

However, this may be irrelevant, since the type of starport indicate a requisite amount of commercial activities, which such a Roll On Roll Off starship wouldn't warrant visiting in some outback port.

 

[kilemall]

Probably the opposite, since you're practically acting as a floating dock.

However, this may be irrelevant, since the type of starport indicate a requisite amount of commercial activities, which such a Roll On Roll Off starship wouldn't warrant visiting in some outback port.

I was looking at a Traveller RORO being about rapid cargo dispersal and consolidation, not rough field direct landing. Something like 12 hour turnaround coupled with a lot more orbital delivery.


There would be the obvious military use of rapid army deployment for atmo operations. So perhaps subsidized ROROs on tap for call up in emergency use, giving more support for mass cargo movement and economic development.

A proper model would work both ways, population TL and thus trade route tonnage would alter with more positive conditions like subsidized merchants making shipping possible.

 

[Condottiere]

At the scale I was imagining (car ferries), I don't think you actually want to land.

However, if we're thinking adventure class types, they probably will on rough fields, keeping in mind ground pressure.

Despite attempts to simplify it, socio economic political conditions are hard to model accurately, so whatever you come up with is probably as good as anyone else's, at this point.

But you know the old truism.