How to address the problem of the numbers

[tjoneslo]

I'm not saying the routes drawn doesn't conform to the rules for drawing routes¹. I'm saying they don't represent the trade adequately for Carlobrand's purpose of estimating the total number of ships in the Marches.

There are a couple of sources of introduced error by just looking at the map.

As each route is drawn, the value of the trade (using the minimum value from the BTN table) is added to connection between each world on the route. When all the routes are calculated, the lines on the map are drawn based upon the log10 of the total trade between each world.

So the trade between (for example) Feri and Regina is accounted for on the map, it's just hidden under the larger routes.

If Carlobrand wants something more accurate than an order of magnitude estimate for shipping, he and I should be using the actual data (it's only 26Mb text file)

Though I happened to spot one that doesn't yesterday: Lunion and Strouden have a BTN of 11.0, so they should have a big major route between them, presumably via Sharrip.

There is a BTN 11 (cyan) route between Lunion and Strouden, it goes through Gandr.

The suggestion of 3 smaller to 1 larger should be translated by multiplying the total trade between each world by 10/3 before applying the log10 scale. This just makes some of the lines larger.

Why? Does that make sense to you? Because it doesn't make sense to me. Why are existing routes existing instead of non-existing routes that would be cheaper?

Besides, the explanation begs the question: Why isn't there a ship being maintained on the potentially cheaper route?

The decision to follow existing routes (the higher WTN worlds) vs drawing new routes is one of the tweaking decisions for the map drawing.

I've set it higher (meaning more likely to follow an earlier route) partly for map clarity. There are fewer (somewhat larger) lines on the map. When I showed the current results to Joshua (of Traveller Map), he had a negative reaction because this many lines on the map made it more difficult to read.

From this I then generate a (weak) handwave regarding putting shipping containers on ships which are already going in the direction you want them to (which you don't have to pay the overhead on) vs. maintaining your own ships to travel a different route.

I've not done the economic analysis of shipping on a free trader (200 dtons) vs liner (2000 dtons) vs large freigher (20,000 dtons), I've simply assumed the scale of economy applies.

 

[rancke]

So the trade between (for example) Feri and Regina is accounted for on the map, it's just hidden under the larger routes.

Trade from Feri to Regina will predominantly go via Roup. There may be be the odd exception, but in general anything else will be more expensive.

There is a BTN 11 (cyan) route between Lunion and Strouden, it goes through Gandr.

I don't believe it. That would be more expensive than shipping through Sharrip. Not only do you pay for a jump-3 when you only had to pay for a jump-2 (a jump-3 costs about 50% more than a jump-2 in absolute terms, so that adds 25% to the total cost right there), but you have to transship the cargo between J2 and J3 shipping at Gandr, which must add a bit to the cost too. If some enterprising J2 ships can't make a living undercutting a 130% competition, then there's something very wrong.

The decision to follow existing routes (the higher WTN worlds) vs drawing new routes is one of the tweaking decisions for the map drawing.

It's a decision that introduces errors.

I've set it higher (meaning more likely to follow an earlier route) partly for map clarity. There are fewer (somewhat larger) lines on the map. When I showed the current results to Joshua (of Traveller Map), he had a negative reaction because this many lines on the map made it more difficult to read.

That is a valid concern, but if you draw a line on the map that the ships don't actually follow "in reality", what you get is a more legible but less correct map.

From this I then generate a (weak) handwave regarding putting shipping containers on ships which are already going in the direction you want them to (which you don't have to pay the overhead on) vs. maintaining your own ships to travel a different route.

Again I will point out that this is begging the question. There should be no need to maintain your own ships because others would be servicing the cheaper routes in the first place.

You didn't address the passenger factors I pointed out.


Hans

 

[tjoneslo]

A BTN 8 route generates between 500 and 1000 passengers per year, for an average of 750 passengers. Moreover, half (or is it more or less than half?) the minor routes are BTN 8.5, and BTN 8.5 routes generate between 1000 and 5000 passengers per year for an average of 3000 passengers per year. The average of minor routes would therefore be 1875 passengers per year, which is more than three times more than your 500, pushing it well above rounding error territory.

1875 passengers * 4 dtons each is 7,500 dtons.

A BTN 8 Route averages 33,000 dtons of cargo per year. A BTN 8.5 Route averages 66,000 dTons per year. The average for that is 49,500 dTons. The passengers represent 16.5% addition.

While still an under estimate, it would not widely affect the size of routes on the map.

I have not thought of a good way to incorporate the passenger traffic into the map.

 

[rancke]

1875 passengers * 4 dtons each is 7,500 dtons.

A BTN 8 Route averages 33,000 dtons of cargo per year. A BTN 8.5 Route averages 66,000 dTons per year. The average for that is 49,500 dTons. The passengers represent 16.5% addition.

I must have misunderstood your original statement.

While still an under estimate, it would not widely affect the size of routes on the map.

I disagree, as the example of the missing route between Regina and Roup illustrates.

I have not thought of a good way to incorporate the passenger traffic into the map.

Incorporate the increased passenger figures the same way you have incorporated the basic passenger figures?

Or make separate passenger and freight route maps.

Either way you'd need an algorithm that takes the desire of passengers to get to their destination fast, making J3 and J4 more viable, into account.


Hans

 

[aramis]

From this I then generate a (weak) handwave regarding putting shipping containers on ships which are already going in the direction you want them to (which you don't have to pay the overhead on) vs. maintaining your own ships to travel a different route.

I've not done the economic analysis of shipping on a free trader (200 dtons) vs liner (2000 dtons) vs large freigher (20,000 dtons), I've simply assumed the scale of economy applies.

in CT, it doesn't. Well, not past 800 Td. At 1000, the extra crew requirements kick in, and it takes to 20KTd to get back down... after which, it's about flat.
Unless you're using a mixed design system universe, in which case 800 Td is the best hull, period.


In TNE & T4, it caps, due to lack of radiator space and other aspects of the square-cube law.

 

[Carlobrand]

Okay, a couple of questions:

The underlying code used to generate maps went through a complete re-write. The original in C was no longer capable of being upgraded, which I needed to do to alter the parser for the new T5 sectors layout. So I re-wrote it in Python, and added some options. ...

What does this mean in English? I see a number of files with .PY extensions. Do I need a specific program to make it work, or am I just being a little slow of wit? (I do get like that sometimes. )

And, from Aramis, I need a clarification. These maps are posted on the Wiki. They are not posted as GURPS maps. They are posted as Spinward Marches trade maps (and Deneb trade maps, and Corridor trade maps, and so forth). There's nothing there indicating they're not canon for the CT/MT/T5/etc. universe. Is this an error? Do they need to indicate that they're for GURPS use? Does Marc consider that they don't apply to the CT Milieu? Because right now, when someone goes to the Wiki and sees sector maps and trade maps and climate files, they're likely to assume it's canon for the milieu irrespective of rules set and incorporate it into their game. And you've made it pretty clear that GURPS economics in the CT setting is a naughty, naughty thing.

... I have not thought of a good way to incorporate the passenger traffic into the map.

Maybe a separate passenger service map?

Meanwhile, I continue to look at the numbers and try to see how they might translate.

 

[tjoneslo]

Okay, a couple of questions:
What does this mean in English? I see a number of files with .PY extensions. Do I need a specific program to make it work, or am I just being a little slow of wit? (I do get like that sometimes. )

If you read down through the readme.md file on the front page it goes through in great detail. The instructions assume some version of Linux as your operating system, though you can run it on windows too. It does require Python, which is a programming language and program run time. There are two python libraries required, which are not part of the standard python installation.

And, from Aramis, I need a clarification. These maps are posted on the Wiki. They are not posted as GURPS maps. They are posted as Spinward Marches trade maps (and Deneb trade maps, and Corridor trade maps, and so forth). There's nothing there indicating they're not canon for the CT/MT/T5/etc. universe. Is this an error? Do they need to indicate that they're for GURPS use? Does Marc consider that they don't apply to the CT Milieu? Because right now, when someone goes to the Wiki and sees sector maps and trade maps and climate files, they're likely to assume it's canon for the milieu irrespective of rules set and incorporate it into their game. And you've made it pretty clear that GURPS economics in the CT setting is a naughty, naughty thing.

As the lead editor for the Traveller Wiki I consider the GT universe and the CT Universe to be one and the same, and both canon. When (If) the powers that be produce a set of rules that cover the same ground, I'll adjust the program to reflect those rules and rebuild the trade maps.

 

[aramis]

Okay, a couple of questions:



What does this mean in English? I see a number of files with .PY extensions. Do I need a specific program to make it work, or am I just being a little slow of wit? (I do get like that sometimes. )

And, from Aramis, I need a clarification. These maps are posted on the Wiki. They are not posted as GURPS maps. They are posted as Spinward Marches trade maps (and Deneb trade maps, and Corridor trade maps, and so forth). There's nothing there indicating they're not canon for the CT/MT/T5/etc. universe. Is this an error? Do they need to indicate that they're for GURPS use? Does Marc consider that they don't apply to the CT Milieu? Because right now, when someone goes to the Wiki and sees sector maps and trade maps and climate files, they're likely to assume it's canon for the milieu irrespective of rules set and incorporate it into their game. And you've made it pretty clear that GURPS economics in the CT setting is a naughty, naughty thing.



Maybe a separate passenger service map?

Meanwhile, I continue to look at the numbers and try to see how they might translate.

The assumption that the maps are for all milieux is a problem. Also, the wiki isn't itself canon, but contains a lot of canon information...
Likewise, this website isn't canon. Tho' we sling enough around.

Until Thom mentioned it, I was only aware of the ones posted on SJG, and know that they were done by running the whole imperium as a single batch, but had some flawed code. The Wiki used to be a mirror of those.

Noting that there are going to be at least 5 worlds per sector reaching every other sector, that means a long, slow, and finicky process of generating flow-through (which GTFT does NOT account for on any given world), and then collating it.

The problem is that the numbers don't match between any two editions. Even in CT, the costs per ton are different between '77 and '81 editions... and HG is a totally different set of numbers. In a mixed Bk2/HG universe, per parsec, 5000Td J1 is the cheapest way to go; even TL15 HG designs cannot compete. The 2000Td J6 Bk2 is cheaper than the 50KTd HG one... So you get hiccups. (I was mistaken about the 800Td being the cheapest in CT. That's for the MGT core book, and was a math error in the spreadsheet, now fixed.)

Since the relative price varies widely between editions (both in terms of ROI and in terms of cost per ton per parsec), any set of routing maps are going to be only vaguely suggestive of other versions. The Closest to each other will be "pure HG CT", HeroTrav and T20 - because all use the same HG design system baseline.

 

[rancke]

My suggestion is to make an Imperium-spanning map showing the major routes, sector-spanning maps showing major and medium routes, and subsector-spanning maps showing major, medium, and minor routes.

Also, to fuzzy up the numbers. Instead of saying that "about 8 freighters of such and such a size ply this kind of routes", say "from 4 to 12 freighters of from such and such to such and such a size ply this kind of routes".


Hans

 

[Carlobrand]

...As the lead editor for the Traveller Wiki I consider the GT universe and the CT Universe to be one and the same, and both canon. ...

The assumption that the maps are for all milieux is a problem. Also, the wiki isn't itself canon, but contains a lot of canon information. ...

Well, at least we all agree. o:

 

[tjoneslo]

Until Thom mentioned it, I was only aware of the ones posted on SJG, and know that they were done by running the whole imperium as a single batch, but had some flawed code. The Wiki used to be a mirror of those.

Used to be, until Marc started publishing the T5 second survey data on Traveller Map , and started changing both the worlds and the layout of the data.

The problem is that the numbers don't match between any two editions. Even in CT, the costs per ton are different between '77 and '81 editions... and HG is a totally different set of numbers. In a mixed Bk2/HG universe, per parsec, 5000Td J1 is the cheapest way to go; even TL15 HG designs cannot compete. The 2000Td J6 Bk2 is cheaper than the 50KTd HG one... So you get hiccups. (I was mistaken about the 800Td being the cheapest in CT. That's for the MGT core book, and was a math error in the spreadsheet, now fixed.)

Since the relative price varies widely between editions (both in terms of ROI and in terms of cost per ton per parsec), any set of routing maps are going to be only vaguely suggestive of other versions. The Closest to each other will be "pure HG CT", HeroTrav and T20 - because all use the same HG design system baseline.

The routing maps are order-of-magnitue suggestions. Are the differences between the systems really that large?

Or, another way, it may be an interesting challenge to work through the interpretation of the results for the "Pure HG CT" vs the standard GT universe.

 

[rancke]

The routing maps are order-of-magnitue suggestions.

"About eight 1000+ dton freighters plus a dozen or more [ships the size of free traders] will typically work these routes." [FT:18]​

That's a good deal more specific than an order of magnitude. At least when it comes to number of ships; I grant you that '1000+' could cover two or even three orders of magnitude.

And in the case of such routes as the one between Regina and Roup, which ought to be a feeder route but is no (marked) route at all, there's a good deal more than one order of magnitude involved. :devil:


Hans

 

[tjoneslo]

And in the case of such routes as the one between Regina and Roup, which ought to be a feeder route but is no (marked) route at all, there's a good deal more than one order of magnitude involved.

Hans

I promised that once Don and Marc approved the current outstanding set of changes to the sectors in Aslan space, I would rerun the maps to incorporate the changes.

I'll adjust the route-reused variable to something smaller when I do so. Also to replace the data files with their old sector information and add the data generated to another sub-page.

 

[aramis]

Used to be, until Marc started publishing the T5 second survey data on Traveller Map , and started changing both the worlds and the layout of the data.



The routing maps are order-of-magnitue suggestions. Are the differences between the systems really that large?

Or, another way, it may be an interesting challenge to work through the interpretation of the results for the "Pure HG CT" vs the standard GT universe.

100% difference in relationship between J1 and J2 pricing, yes. As in, Bk5 based J2 is a cost per parsec of 1.3x J1 or so, and Bk2 is 1.05x J1 or thereabouts; it gets wider as Jn goes up.

It means the distance mods have to be recalibrated. But I haven't done the work for GT other than a couple comparisons; the GT book lacks the needed data, (ops costs other than fuel), and it's not a system I use...

Note that all of these are in minimum cost hulls (with a 50KTd limit for HG) and are expressed as multiples of J1 cost.

Note: these are costs to operate, not prices paid for shipping.

System	J1	J2	J3	J4	J5	J6
Bk2-81:	1.0	0.7	0.6	0.8	1.2	1.7
Bk2-77:	1.0	0.7	0.6	0.7	0.4	1.2
HG-TL15:	1	0.84	0.9	1.09	1.51	2.73
MGT:	1.00	1.00	1.20	1.60	2.70	13.70
Relative Ton-Pc	1	0.78	0.8	0.9	1.12	1.65
Bk2-77	1	1.32	1.89	2.77	2.22	7.29
Bk2-81	1	1.34	1.95	3.01	5.77	10.02
HG	1	1.69	2.7	4.36	7.57	16.38
MGT	1.00	2.00	3.50	6.30	13.60	82.40
GT Core	1	1.56	2.4	3.59	5.59	9.9

[tc=7]Minimums per parsec[/tc] [tc=7][/tc] [tc=7]Per Jump N[/tc]

 

[Carlobrand]

Used to be, until Marc started publishing the T5 second survey data on Traveller Map , and started changing both the worlds and the layout of the data.



The routing maps are order-of-magnitue suggestions. Are the differences between the systems really that large? ...

I don't think so. I'm thinking tens of percentages rather than orders of magnitude. However, GURPS has a built-in fee variation with jump range, and CT tries to apply an (cough absurd cough) invariant rate regardless of jump range:

Book 2: "All cargos are carried at Cr1,000 per ton. ...Passengers will pay the standard fare for the class of transportation they choose: Cr10,000 for high passage, Cr8,000 for middle passage, and Cr1,000 for low passage. Passage is always sold on the basis of transport to the announced destination, rather than on jump distance."

Hans is of the opinion that it's a "game artifact, not a setting detail," after noting instances in adventures where the rule was ignored. However, there is no other CT data on shipping costs, so I assume it as written or I make up my own values for jump-2 and higher, which derails the idea of coming up with numbers others can use.

Query: Is T5 second survey data different from GURPS data? Will it mean that the map is no longer completely applicable to the GURPS setting, or are there any plans to make the thing so a person could switch between pre-second-survey and post-second survey data?

...Or, another way, it may be an interesting challenge to work through the interpretation of the results for the "Pure HG CT" vs the standard GT universe.

Working on it. It's a challenge, more because some of the differences are difficult to quantify and therefore subject to debate. For example, what is the impact on tonnage shipped of a 20%-of-value shipping charge versus a 7% of value shipping charge? CT items shipped through space suffer a higher increase in price because it costs more to ship them and - as Aramis points out - the average value per ton of CT shipped goods is lower by half. That means they're less competitive verses local goods. Not a problem if the locals can't make the goods, or the shipping world can offer a qualitative advantage to justify the increased price (making something more portable or with more features, for example), or the shipping world can compensate the increased shipping cost by using improved productivity to lower base cost, but how does one evaluate what percentage of trade will or won't be affected? But, as I said, I think that would lower trade by tens of percentages, not by orders of magnitude.

 

[Carlobrand]

...

Note: these are costs to operate, not prices paid for shipping.

System	J1	J2	J3	J4	J5	J6
Bk2-81:	1.0	0.7	0.6	0.8	1.2	1.7
Bk2-77:	1.0	0.7	0.6	0.7	0.4	1.2
HG-TL15:	1	0.84	0.9	1.09	1.51	2.73
MGT:	1.00	1.00	1.20	1.60	2.70	13.70
Bk2-77	1	1.32	1.89	2.77	2.22	7.29
Bk2-81	1	1.34	1.95	3.01	5.77	10.02
HG	1	1.69	2.7	4.36	7.57	16.38
MGT	1.00	2.00	3.50	6.30	13.60	82.40

[tc=7]Minimums per parsec[/tc] [tc=7]Per Jump N[/tc]

Costs to operate per ... ton of ship? I don't understand the table.

 

[rancke]

Book 2: "All cargos are carried at Cr1,000 per ton. ...Passengers will pay the standard fare for the class of transportation they choose: Cr10,000 for high passage, Cr8,000 for middle passage, and Cr1,000 for low passage. Passage is always sold on the basis of transport to the announced destination, rather than on jump distance."

Hans is of the opinion that it's a "game artifact, not a setting detail," after noting instances in adventures where the rule was ignored. However, there is no other CT data on shipping costs, so I assume it as written or I make up my own values for jump-2 and higher, which derails the idea of coming up with numbers others can use.

There is perfectly good CT data on shipping costs, namely the ship design rules and the operating costs. Unfortunately, people don't get the same results when they work them out. (Also, the results differ from Book 2 to HG and according to what edition you use). But the results do at least tend to be in the same ballpark.

Costs to operate per ... ton of ship? I don't understand the table.

Per ton of freight shifted.

My suggestion would be to distill these numbers down to the following rules of thumb:

1) On one-parsec routes J1 ships are cheapest.

2) On longer routes J2 and J3 in whatever combination makes for the smallest number of jumps (2: J2; 3: J3; 4: J2+J2; 5: J2+J3; 6: J3+J3; etc., etc.) are cheapest.

3) For passenger lines and where using it will reduce the number of jumps, J4 is competitive.

4) Sometimes other considerations than cost can affect the solution. Example: On a J4+J3 route, a J4 ship may service both legs of the route, jumping short on the J3 leg if enough passengers appreciate the convenience of not having to transship at the intermediate world.


Hans

 

[Aramais]

As the lead editor for the Traveller Wiki I consider the GT universe and the CT Universe to be one and the same, and both canon. When (If) the powers that be produce a set of rules that cover the same ground, I'll adjust the program to reflect those rules and rebuild the trade maps.

Through 116, I assume, for "event" purposes.

I have been reading this discussion. It would be interesting to see how it works under T5's RU system. However, I must say that my conclusion is that I don't understand it. I merely assume that commerce will occur, because that seems to be a matter of human nature.

FWIW, I tend to assume that long distances are traversed by "uniques." Wine, entertainment, specialty foods...things simply can't be obtained or made locally. Less unique bulk stuff moves as well, but shorter distances.

On the canonicity of the trade routes depicted in the wiki -- is it fair to say that they should noted as "likely trade routes" as opposed to something more canon.

I approach this gently, because for most referees the important question is getting adventure opportunities. This would be the key question I would ask: how do these work out in practical terms? What will this mean for a regular game?

 

[Aramais]

Through 116, I assume, for "event" purposes.

Or through 1116.

 

[tjoneslo]

Regina has a WTN of 5.0. Efate has a WTN of 5.5. They lie six parsecs apart. Their BTN is 5.0+5.5-1.5 = 9. That should show up on the trade route map as a J3 feeder route connecting Regina with Efate via Knorbes. It doesn't.

Regina and Roup has a BTN of 8.5. That's just a minor route, so for some unexplained reason J3 ships are not allowed to bridge the 3-parsec gap between them. But Feri and Regina has a BTN of 9.0 and Extolay and Roup also has a BTN of 9.0. That gives two feeder routes and a largish minor route between Regina and Roup. So at the very least there should be a feeder route marked between the two; if you allow the BTN 7.5 route between Dinomn and Roup via Regina to add its little bit, it even arguably adds up to a main route.

Rhylanor and Regina has a BTN of 9.0 and Porozlo and Regina has one of 9.5. Apparently they both connect to Regina via Yori. But Yori and Regina has a BTN of 9.0. That's three feeder routes going between Yori and Regina, so should be upgraded to a main route.

There's enough traffic for a minor route between Inthe and Regina (BTN 8.5) and between Inthe and Yori. For some unexplained reason that doesn't warrant marking a route on the map because there's a 3-parsec gap involved. But marked or not, the trade still takes place and the ships to carry that trade must exist. So if we rely only on the trade routes marked on the map, we fail to account for the existence of those ships.

I tweaked the route reuse setting in the code and generated the routes for just the Spinward Marches sector.

Regina-Efate now connects through Roup. The Roup-Regina route has been upgraded with the additional traffic. Rhylandor to Regina no longer goes through Yori, but Inthe and Treece in addition to Yori gives that route an upgrade too.