Another Bottleneck

[Baldy's Boss]

Jubilee is my successful current game...getting more money from fewer trains than previous games I've taken through the 2010s (perhaps because of inflation since its 1887 startup).
A persistent bottleneck however has been the wood traffic from Shorside Marsh Woods,using a productive forest near Beepool East station that joins into the longer run from the less productive Sundhattan forest.
I've lately added a second feeding run into Beepool East,from Stanton forest,which turns a modest profit from there,but the other forests along the way are served by trains that have trouble breaking even,and are not yet served because of my Appalling reputation with a local authority (the two active stations on that side serve forests that were more productive when I decided to build than they have been since service actually started).Where the "future station" is noted,I planted lots of trees and spent a million-plus on advertising but they still hate me.

Back to Shorside Marsh Woods.I've been trying to increase throughput,shunting Sundhattan service to other tracks,adding a depot just before the turnoff so that trains to Sundhattan don't take the turnoff if they need service,and most recently adding the tubular-bridged alternate route for trains that leave Beepool for Shorside and don't need service.But there are still big piles of wood.How do I best use the limited space?

[Alberth]

This shows your problem at Shorside Marsh Woods, I think, a 1200 tonnes/month forest, and no train loading!

woods_pickup1.png (521.55 KiB) Viewed 2761 times

If you look at the outer (northern) platform, there is a train moving to it just as I took a screenshot. The question is then why only now, and not earlier? That needs a little explanation.

Just before a train enters a new block protected with a path signal, it claims a path for itself through the entire block. In this case there is only one track, so "a path" is the same as "the entire block" here. The train just going in now just claimed a path from its current position, through the station, over the bridge, up to the path signal just across the bridge. With this path secured, it can start moving to the station for loading. It could not do this earlier due to the leaving train that still occupied some tiles at the far side (ie left side) of the bridge.

The solution to improve usage of the outer track is to shorten the length of the path that needs to be claimed. Best place is just behind the platform, by moving the bridge one tile to the left. Terraform a flat tile just behind the platform, move the bridge (track under the bridge probably gets an extra bend to make it fit), and add a path signal just behind the platform.

That should fix the outer track, I think. Next problem is the inner platform. You have a heap of trains waiting for the outer track, and nothing on the inner track. Apparently, the path finder finds the first junction more attractive to use. The simplest solution is to make the inner platform available for the waiting trains by adding a few tracks. I'd also remove the track that exists now to get to the inner platform from the main line, as it isn't used anyway, and you do pay infra structure costs for it.

Likely the next problem of this station is having enough capacity to get rid of all the full trains, but that's a next chapter, after fixing some wood dropping problems near the Sawmill.

woods_drop.png (543.74 KiB) Viewed 2761 times

Your two platforms for dropping wood are not enough. There is usually a queue before it with trains waiting for a platform. One small reason is another path reservation problem. In the image, the train at the far right moved out of the depot, and is now unloading. However, trains don't move at all until they have a path claimed through the block up to the next signal. In this case, that path goes out the platform, and then onto the entry/exit tracks. That path blocks the exit of the next train right next to it. As you can see it turned, meaning it is ready to leave, but it cannot claim a path to the next signal, since the path claimed by the unloading train is in the way. As a result, it waits, making the platform less useful.
The solution is to either remove the depot, or to add a two-way path signal facing the platform in-between the platform and the tracks at the right side.

The above however is probably not enough, you simply need more platforms here for unloading. One option is to build a new station where the long queue is now. Another option is to re-organize the existing station. Switching to roro would be useful I think, since you'll only get more wood, so planning for even more capacity is not wasted. If you don't want to do that kind of drastic shuffling, you can improve the current station instead. If you watch the station for a while, you'll notice the left wood-drop platforms are mostly empty. It would be nice if you could use those, wouldn't it?

Not really a requirement, but it makes life easier: First, move the goods pickup platforms out of the way, either by swapping them with the left wood drop platforms, or by building new platforms for them, Perhaps orthogonal to the existing platforms, so you have space for extending wood-drop even further if the need arises (although that makes ever switching to roro more complicated).
For the wood-drop platforms, build a track for entering all platforms, and another one for exiting. These get connected to both wood lines. In time, I expect you'll need a 3rd or 4th line there eventually, but that's a problem for the future.

Once that is nicely running have a closer look at Sundhattan forest.

woods_pickup2.png (464.11 KiB) Viewed 2761 times

Currently it's very empty, but that may be due to the long queue to drop wood. Forest output growth needs a loading train!

[Baldy's Boss]

Loading trains don't seem to have stimulated much production at Stanton.
Is the attached re-engineering at Shorside Marsh & Beepool East productive?

[Eddi]

spent a million-plus on advertising but they still hate me.

Advertising only helps your standing with the town's inhabitants, not the town's city council. (that's what bribes are for)

also, trees only help in places where there were no trees before.

but the least ethically problematic way to improve town ratings is by providing a bus service in town, before you start doing "environment work" for tracks and stations. every time a bus arrives at a station it will improve town rating a bit, with lots of busses it will regenerate quickly.

[Alberth]

Loading trains don't seem to have stimulated much production at Stanton.

Production increase doesn't happen that quickly. It's a random process, but with higher station ratings, the chance for increase is slightly higher than the chance for decrease. Shorter trains are probably better, but you'll need a 3rd train soon then.

Is the attached re-engineering at Shorside Marsh & Beepool East productive?

The queue at the drop station is gone so that seems to work. On the other hand, wood pickup at Shorside Marsh still mostly uses one platform, so there seem room for improvement there.

[Baldy's Boss]

Loading trains don't seem to have stimulated much production at Stanton.

Production increase doesn't happen that quickly. It's a random process, but with higher station ratings, the chance for increase is slightly higher than the chance for decrease. Shorter trains are probably better, but you'll need a 3rd train soon then.

Is the attached re-engineering at Shorside Marsh & Beepool East productive?

The queue at the drop station is gone so that seems to work. On the other hand, wood pickup at Shorside Marsh still mostly uses one platform, so there seem room for improvement there.

Plunbrook remains low-production and they still hate me in Finway.
But I think that,after expensive mountain-ripping,I've created a system that will supply trains to both loading platforms at Shorside Marsh.
EDIT TO ADD:
Nope...per new attachment,backlog is back to a peak!

[Baldy's Boss]

I've kept trying to ease throughput but the backlog has kept persisting.

[Alberth]

Why does this happen?

Your X cross and the additional signal at the outer track at Shorside Marsh Woods are effective, it uses both platforms now.

There are no signals behind the platforms at Beapool East. Remember what I said about trains entering a new block with path signals? They claim a path through the entire block to the next signal. Chances are that paths behind the platforms will collide between trains at different platforms. Result is that you don't use the second platform as much.

So at 2 platforms loading, and less than 2 platforms unloading, the only possible outcome is a big pile before unloading.


How to fix?

Decide whether you want 2 or 3 unloading tracks. If you want 3, take one platform away from the left side, it's not used anyway. Shift your pickup one platform to the left, and then you have 3 platforms for unloading. I described above how to get almost 4, that's an option too, but a lot more building and shuffling stuff.

Decide how your trains run through the unload station. Now you have a partly roro, partly terminus, which is more difficult to optimize. If you use roro, connect all exits to it, and clear out all track that is useless. To get better flow, make an exit track after the platform, just like the loading station. Trains should leave the platform as fast as possible to make room for the next train.

Thirdly, fix your depot handling. For good flow, you can't have trains with 20-35% reliability. Preferably use a side-track for this, so other traffic isn't bothered with it. Alternatively, do this at a spot where they have to wait anyway. Just before a roro station is often a good spot, but don't let trains block other platforms than their own. Typically this means you add a dedicated depot for each platform without option to cross to the other platform after it.


Note that you have an awful large number of trains here. With that number, it will pile up somewhere, always. I think you can scrap a few trains at some point, to reduce the queue lengths.

[Baldy's Boss]

Trains from Sundhattan forest are expected to reverse at Beepool East,while those from Shorside Marsh can go straight through.There are paths to Shorside Marsh with and without depots.

EDITING TO ADD new save...here are signals after the unloading platforms.

[Alberth]

Trains from Sundhattan forest are expected to reverse at Beepool East,while those from Shorside Marsh can go straight through.There are paths to Shorside Marsh with and without depots.

Why this distinction on destination? It's much simpler and more effective (in flow) to let all go through in roro, then afterwards branch out in different destinations.

I just clicked a few trains that broke down, and saw such low reliability. Maybe the depots are not at the right place then?

[Baldy's Boss]

Trains from Sundhattan forest are expected to reverse at Beepool East,while those from Shorside Marsh can go straight through.There are paths to Shorside Marsh with and without depots.

Why this distinction on destination? It's much simpler and more effective (in flow) to let all go through in roro, then afterwards branch out in different destinations.

I just clicked a few trains that broke down, and saw such low reliability. Maybe the depots are not at the right place then?

Check the October save (just added) for latest flow.
The roro continuation is much more out-of-the-way for a Sundhattan train than a Shorside train.
There certainly should be enough depots whichever way you leave Beepool East.

[Alberth]

Hi,

Check the October save (just added) for latest flow.

I just saw that. Unfortunately, that won't happen until I am done with working.

The roro continuation is much more out-of-the-way for a Sundhattan train than a Shorside train.

Not sure how you reach that conclusion, from my head, Sundhattan is much further away, so a few tiles in the wrong direction is less bad, relative to the entire path length, but fair enough.

There certainly should be enough depots whichever way you leave Beepool East.

From what I saw, trains breaking down did not just leave Beepool East.

[Alberth]

I had another look and found two wrong signals. Also, I cleaned up the tracks after junctions, have a look (left=before, right=after):

lanes.png (108.84 KiB) Viewed 231 times

The two dark-blue ellipses are signals pointing in the wrong direction, which explains why no train was using the second track there.

The orange ellipses are signals that should not be there. Path signals should be used at 'safe' stopping places, ie where a train can stop without blocking other trains. In this case, these signals caused blocking of the junction before, resulting in bad throughput. (Basically, if there is not enough place at either direction, a train should wait until one of them has enough place. If it picks a direction earlier, it may happen that the other direction is faster in making room, and the train is blocking progress for other trains. Note that "not enough space at either direction" only happens when both tracks to the station are completely filled with waiting trains, in that situation you're not in a hurry to reach the unloading, as there is a huge traffic jam ahead anyway.)

The yellow marked tracks caused additional switching of trains between tracks for no good reason. Switching in itself isn't bad, but due to bad signal placement, they then also block other directions. The blockage is worse than the benefit of switching, so it's better here to remove the tracks. Note that the path finder understands both tracks lead to the station, and it spreads trains between both lines.

[Baldy's Boss]

I can't believe I missed those wrong-way signals!
Fixing them seems to have had a good effect on the backlog though it will take time to sort out.
They also explain why trains from Sundhattan kept waiting at the signal on the now-removed connecting track between the bridges.This should improve Sundhattan service as well as Shorside Marsh service since they now have a clear path.