ORIGINAL: 76mm
Thanks, although this is kind of funny, because that's how I started playing, but when I ran into a logistics problem and posted about it, several players told me that I was doing it all wrong, and that logistics should flow both ways, and that I shouldn't "shape" it as you suggest. [&:]
Also, doesn't your rail need to take excess zone supplies back to SHQ? Wouldn't a traffic sign used to shape truck traffic block that?
Like I said, I still don't get it...
Well, I've primarily been using that setup for offensive bases where all my needs are purely one-way - I haven't captured a city in the region yet, so nothing's going back up the pipe and it's all coming down. Thus, the need to ship things back to the SHQ doesn't exist as yet and doesn't pose a problem. There IS a good chance that once the local city has been captured and hooked up to the network it'll be necessary to rethink a bunch of traffic signs in the region, however.
That being said, to the best of my knowledge logistical capacity is "direction agnostic" - i.e., it doesn't matter where it comes from, if it's in the hex it can be used. Thus, as long as the rail provides logistical capacity running up to a railhead, that same existing capacity can be used to ship it back up the line to the SHQ as long as there's spare capacity.
Taking a look at your post, the problem wasn't that you were shaping logistical lines per se - the problem was that your use of traffic signs completely choked out available capacity. The method I describe only works if you're absolutely sure you have sufficient capacity coming from behind to be able to focus everything forward.
Lemme see if I can diagram it out.
(Rail) -> (Railhead+Truck Station) -> (Road to Front)
So same hex map as before, but let's change the parameters some. This time, for whatever reason, the rail station at the SHQ isn't pushing as much capacity down the line - maybe you branched off or something, whatever. Point is, your rail is only providing you with 500 train points, while your station is providing 1000 truck points as before. If you were using the roadblocks I suggested earlier, you get this:
(500 train points) -> (500 train points + 1000 truck points) -> (1000 truck points)
So the issue here is that you're bottlenecked by your SHQ rail - sure, you have 1000 truck points available at the front, but you can only rail in 500 train points worth of stuff, because that's all the capacity you have available. Thus, although you have in theory 1000 truck points available, they can only carry 500 points worth of stuff because that's all that the rail points can pass on to them to carry. This, by the way, was what was happening in the post you described - you had a lot of available capacity on the outward channel, but not enough coming in, and thus you were getting bottlenecked at the rail line despite having a lot of spare capacity down the line.
So what would we do? Well, assuming that your trucks actually have enough AP to go all the way back to your capital whole, you could remove the blocker entirely, in which case you end up with this scenario:
(500 train points + 500 truck points) <-> (500 train points + 1000 truck points) -> (500 truck points)
That looks better on the SHQ side, but now we have a problem - you're bottlenecked by the truck points available for the front now. You can ship in 1000 points worth of stuff down to the railhead by combined rail and truck, but you can only devote 500 truck points pass things down to the troops at the front. That's no better than before.
So what's the solution? Well, in this case, the best thing to do would be to slap a 50% blocker heading back towards the SHQ, so that only half the normal output can pass through. That'll get us this scenario:
(500 train points + 250 truck points) <-/-> (500 train points + 1000 truck points) -> (750 truck points)
As you can see, we're now making the best of a bad situation - we can shift a total of 750 points worth of stuff from the SHQ to the front, because at every hex there's 750 points at least available for us to use. That's the key to logistics - logistical lines are defined by their weakest links. They need to form a continuous chain of logistical capacity in every hex they're tracing their way down, and they're limited by the hex with the LEAST available logistical capacity.
Note, by the way, that this chain should in theory work both ways: You could potentially send 500 points worth of supplies from the SHQ to the front, and then have the front send back 250 points worth of obsolete equipment to the SHQ, and that's fine because you have 750 points available. But if you were trying to send 750 points worth of supplies down the line and return 250 points worth of obsolete equipment back up, you're out of luck - there's not enough logistical capacity to do both.
Couple more diagrams in case you're having trouble with the concept of bottlenecks. Let's say you have a chain of hexes with, for whatever reason, differing logistical capacity, like so:
(SHQ) -> (Hex) -> (Hex) -> (Hex) -> (Front)
Right! Now we need to move supplies from the SHQ to the front. Let's say the available logistical capacity looks like this:
(5) -> (5) -> (4) -> (5) -> (5)
How many supplies are getting to the front? Four units, because that's the lowest in the chain. Every other hex in the chain can pass up to five units, and all the hexes BEFORE that central hex might actually be passing five minutes to the front, but once they get to the central hex one of the packages slips out of their hands and all they have is four units which is what they pass on down the line.
Now let's take another scenario:
(5) -> (5) -> (5) -> (1000) -> (1000)
How many supplies are getting to the front? Five units, because again that's the smallest number in the chain. The hexes past the central front could take up to a thousand units, but the central hex can only pass on five units, because that's the limit of its capacity, so that's all the front will get.
One more scenario:
(1000) -> (1000) -> (1) -> (1000) -> (1000)
How many supplies are getting to the front? One unit, because that central hex can't handle passing on more than a single lone unit, despite the fact that all the other hexes are big and burly and can take a thousand units.
Picture, if you will, the second hex rolling up, a big massive longshoreman with bulging muscles easily lifting a thousand boxes, bellowing "All right, shrimpy! Got a delivery here for ya!" before slamming all thousand boxes to the floor. The central hex, a wide-eyed toddler, looks at the pile, gingerly grabs a single box with both arms, and then waddles over to the fourth hex, another big longshoreman, who looks at the toddler and goes "What, is that it? OK, then!" before carefully picking up the box between thumb and forefinger before passing that lone box to the front.
And that's how bottlenecks work.
