Signalling problem (solved); And a better junction

[komrade_toast]

Hello fellow Factorionites,
I wish my first post on the forums wasn't me asking for help, but that is not the case. I have a decently large rail network, separate mining sites, and a few factories along the rails. Everything in my base is delivered by trains and I try to use as few belts as possible. My main unloading station has 24 spots for trains to station and unload at. All unloading is done by logistics robots (except fluids, I use pumps there). This station is probably over-signaled, but with fewer signals I seem to have more deadlock problems. The problem I am looking for a solution to is this:

Deadlocked Intersection

Full size available here: http://i.imgur.com/95G4CAA.jpg

Map of Network

Full size available here: http://i.imgur.com/J31ZcHK.png

I probably built the station too close to the 2-way to 4-way T intersection, but that can't be changed now. The problem seems to be that when 2 trains arrive at roughly the same time they both want to enter the same unloading station. This causes one to sit at the intersection and just make things go from bad to worse. I have enough stations here to support every train on my network, so that shouldn't be an issue. If someone could help me and show me a way to signal this well, then I would greatly appreciate it. I have read Antaios' post "Stations, Junctions, and all things deadlock", but could not glean a solution from it.

On a side note: If someone knows of a better 2-way to 4-way intersection (preferably a loop) i would love to see it; And should I split my 2-way track in to a 4-way track BEFORE the intersection, or do it AT the intersection like I have now. I can place 3 pieces of track between all of my tracks, just to let you know the size if you care to show me a better intersection.

Oh, and if anyone wants the blueprints for Goku and Vegeta there I will post separate blueprint strings for each upon request (requires the "color coding" mod by d3phoenix. Available here: viewtopic.php?f=93&t=13907).

[DaveMcW]

Add space for 2 trains to fit at the same station. You should have enough room to move everything down, maybe skip the second row on the furthest right stations if you need more room.

Also, you must use chain signals inside your T-junction. Putting normal signals inside caused the train to block the intersection.

[komrade_toast]

So i should replace all signals in my t-junction with chain signals?

And you are saying I should move these rails down and extend each station itself?

Rails

That seems like a good idea. But, i think that it won't help solve the problem. Yes I could stack two trains at each station, but what if two still arrive at about the same time and want to go to the same station, while one train is already docked there? My problem is that when two trains arrive, only one can enter the tracks at a time. Before they even enter the tracks they have already decided on a station.

Should I keep the second entrance rail (the bottom horizontal rail in the screenshot, just above the arrow)? I added that to help mitigate the problem and it helped significantly, for a time.

[blizgerg]

A chain signal basically tells the train "Pass the chain signal only when the train can successfully leave the chain signal block." The effect is that a series of chain signals says to the train network do NOT stop or wait in the blocks defined by the chain signals.

So on your rail crossings (and elsewhere as needed) you want to use the chain signal to tell the path finding to not stop in the crossing and block it.

Also: viewtopic.php?f=18&t=18621 pretty good reading on it.

[komrade_toast]

I already read through the post you mentioned (in fact it is in my favorites bar). I have re-done the tracks as close to what I believe you suggested as I could. It seems to have solved my problem. I will post any updates if the system runs in to any deadlocks. I replaced all signals in my t-junction with chain signals (I do know how they work). I also moved the tracks down so two trains can dock at each station. I have some minor problems with trains backing up at the t-junction, but it isn't to big of a deal. Should I convert the horizontal rails before the entrance to the junction to 4 way rails?

Updated Tracks

Full size available here: http://i.imgur.com/2IOlJBs.jpg

Map

Full size available here: http://i.imgur.com/jrkkGkz.png

[komrade_toast]

I went ahead and converted the rails before the junction to 4-way rails. This has helped A LOT with my backup problems. If you or anyone else knows of an intersection design that would fit in this small of a place and be more efficient I would love to hear of it (and see it).

Tracks

Full size available here: http://i.imgur.com/lbHIVw6.jpg[/url]

Map

Full size available here: http://i.imgur.com/GNmqIRn.png

Converting to 4-way tracks before the junction has helped tremendously. Smooth flow of trains, and no deadlock problems anymore.