Starports Error?

[Icosahedron]

Hi,
I've been playing Traveller for nearly thirty years and I've just bought my first GT book - Starports.
I have a query. On page 58 is the Port Modifier Table. It produces a port modifier that increases as you go down the table - ie the port modifier increases as the UWTN decreases.
This creates a situation in which the port gets smaller as the world trade gets larger.
Is this an error, am I doing something wrong, or is there a rationale that explains this?

Why should an increase in trade reduce the size of a starport?

I discovered this when I was building a starport and decided to see what difference an increase of TL would make to the size and throughput of the port on my Pop 7 world, but I found that when I increased TL from 11 to 12, it also changed the WTN from 4.5 to 5 and because of the negative effect of the port modifier table, the TL gains were cancelled out! (4.5+0.5 became 5.0+0.0) Surely this is not right?

 

[Valarian]

It's the miniaturisation. The goods get smaller as the tech level goes up, so you obviously don't need as much space.

<tongue firmly in cheek>

 

[Greek Letter Moshpit]

Maybe the port is bursting at the seams and thus bottlenecks trade? IIRC, the WTN scale is exponential, with a unit difference being an order of magnitude bigger or smaller.

Thus, half a unit (the 0.5 increment you talked about) would be a 10^0.5 ~= 3.2x increase in trade through the port, assuming no bottleneck.

 

[mbrinkhues]

At least there is no errata on the sjgames website. Maybe asking the question there (one of the authors of Starports is a regular reader/writer) would help

 

[Icosahedron]

Thanks guys.
One of the Starports authors found my query here and sent me a PM.
GLM's bottleneck answer is on the right lines, it seems.
A class IV port helps to uplift a WTN 4.5 world, but has no effect (or at least, not tripling) on a WTN 5.0 world.

 

[Anthony]

It's not a bottleneck issue per se either. It's mostly a resolution problem. A class IV port on a UWTN 5 world has more traffic than a class IV port on a UWTN 4.5 world, it just doesn't have quite enough extra traffic to qualify for a full +0.5 (i.e. WTN goes from 4.8 to 5.2 or some such).