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Author Topic: Primer on railway signals [work in progress]  (Read 6036 times)

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Offline ӔO

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Primer on railway signals [work in progress]
« on: September 11, 2012, 09:46:46 AM »
I've created a little demo on when and where to use the various signals.

Various concepts, relating to the signals, are touched upon so that players can get a better understanding of how to keep their networks working like a well oiled machine. I think the important one is "Line capacity", or how many trains can smoothly fit within the line without jamming or working very slowly.


I don't seem to be able to come up with a way to use pre-signal just yet, since its function has changed slighty, but hopefully I can include it somewhere.

There are signs placed about the map for the various uses for the signals. There are also some layout suggestions for the infrastructure to improve flow or prevent jams. Unfortunately, they don't auto translate, so they are all in english.



http://dl.dropbox.com/u/17111233/signal_demo_v01.sve
Simutrans version: 111.3.1
Pakset: pak128.Britain 1.12


comments, suggestions and criticism are all very welcome.

Offline jessfarnsworth

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Re: Primer on railway signals [work in progress]
« Reply #1 on: March 05, 2013, 11:11:48 PM »
Thanks for the link.  Unfortunately I can not load a sve file in my firefox browser.  I use an old version of Ubuntu and it wont support it.  Thanks anyway

Offline jessfarnsworth

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Re: Primer on railway signals [work in progress]
« Reply #2 on: March 05, 2013, 11:18:21 PM »
ok, figured out i need to load it in simutrans as a saved game.  Did that and got no narrowgageway error and a crash when I tried to load it.

Offline Vladki cz

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Re: Primer on railway signals [work in progress]
« Reply #3 on: May 26, 2013, 05:29:30 PM »
Hi, nice tutorial, although I do not need it any more, I hope it will be helpful for many newbies. Thank you for making it.

I don't seem to be able to come up with a way to use pre-signal just yet, since its function has changed slighty, but hopefully I can include it somewhere.

I have a use case: two track main line, with one-track branch, that is served by more than one train. As you suggest in you scenario there is one bi-directional signal at the beginning of the branch. But if second train comes when the branch is occupied - we have deadlock. A pre-signal on the main line in front of the branch forces the second train to wait on the main track, until the other leaves the branch. Yes I know it will block the main track, but at least not forever, and in some space constrained situations it is acceptable solution. Not ideal, but acceptable. ;) Something like this ascii art:
S - signal (bi-directional), < and > Signal (uni-directional), P pre signal (uni direcitonal), - and | track, + switch.


           |
           S
           |
---->----P-+->---->---
----<----<-+-P----<---

Offline Ters

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Re: Primer on railway signals [work in progress]
« Reply #4 on: May 26, 2013, 09:05:23 PM »
Valdki's solution is the only really useful use case I know of also. There are a few other I can think of, but they are a bit convoluted and there are likely better solutions. The one thing they have in common is that pre-signal plus a normal signal can be used to simulate a single-sided signal. (A single-sided signal is a hypothetic signal which unlike a one-was signal allows traffic in one direction, without affecting it, while functioning as a normal signal in the other.) If the S in Vladki's example was a single-sided signal that only affected trains leaving the branch, the Ps could be normal signals and everything would work much the same.  (One would also need to remove the one-way signal next to the Ps to prevent trains from being stopped in the junction, blocking it.) Such simulations don't always work, at least not without cascading effects.