Hallo,
I've a problem to build a working priority merger; At point "A" in the picture the strait line shall be the priority line while the trains at the small station shall wait. For optical reasons I'm looking for the best solution that works only with signaling and that comes without 90°connections.
On the other side I set up a variant with a path signal long before the merger, but this creates a very large signal section so I would like to avoid this.
I've read http://wiki.openttdcoop.org/Priority already but I somehow I don't get it.
Thanks for any ideas!
To stupid for priority mergers
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Re: To stupid for priority mergers
The priority merger in its simplest form is really simple — it consists of just two signals! Here's an example how it would look in a situation similar to yours:
The most importand are signals C and D. C is an entry signal that will turn red if D is red. The exit signal at D needs to be two-way, so that trains can pass it in the correct direction, but the merger is controlled by the part that faces the opposite direction.
The trick here is that the signal information travels along all paths through the block — not just the ones that a train can take, but even sharp corners. If the bypass track is occupied, like in the image, the opposite-facing signal at D will become red, and this information will travel through the junction next to E to the entry signal at C. Since there are no other exit or combo signals in the block, the entry signal will become red.
The basic signal at B is very important. If there were no signals between D and the track split, the both branches between C, A and D would constitute a single block. A train that enters the station would be occupying the whole block for the purpose of block signalling, even though there are free paths through the block. The opposite signal at D would become red, which would make C red too; in effect, the train would be blocking itself!
The most importand are signals C and D. C is an entry signal that will turn red if D is red. The exit signal at D needs to be two-way, so that trains can pass it in the correct direction, but the merger is controlled by the part that faces the opposite direction.
The trick here is that the signal information travels along all paths through the block — not just the ones that a train can take, but even sharp corners. If the bypass track is occupied, like in the image, the opposite-facing signal at D will become red, and this information will travel through the junction next to E to the entry signal at C. Since there are no other exit or combo signals in the block, the entry signal will become red.
The basic signal at B is very important. If there were no signals between D and the track split, the both branches between C, A and D would constitute a single block. A train that enters the station would be occupying the whole block for the purpose of block signalling, even though there are free paths through the block. The opposite signal at D would become red, which would make C red too; in effect, the train would be blocking itself!
Last edited by odisseus on 29 Feb 2020 22:00, edited 2 times in total.
Re: To stupid for priority mergers
Great, thanks a lot!
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