Junction Signalling

[colourlight]

At a double track junction track A crosses track B to get to branch C (algebra). However the signalling system does not recognise a train crossing track B and the signal on track B shows a proceed aspect. If the timing is wrong a train on track B passes through the train crossing onto the branch line. Although there are no ill effects and both trains proceed merrily on their way it does not look very professional, lol. Is there anything I can do apart from installing a crossover from track A to track B then a lead onto the branch line? Thanks in advance.

 

[trev999]

Hi colourlight - This situation has been discussed many times and several solutions have been proposed.

The crossing is known as a diamond crossing due to the shape formed by the rails. If you search for that text on the forum you will surely come across some of the arguments.

One of them involves creating a junction on a piece of isolated track which no train can ever reach. This can be submerged below ground level so as not to distract the observer. Name the junction X1 for example.

Now any train wishing to traverse the crossing should request a permit for the junction X1 before approaching it. Use "Wait for junction permit" driver command <kuid:131986:210011> which will hold the train until a permit is granted.
Once the train is clear of the junction issue a "Release Junction" command <kuid:131986:210012> to allow other trains to access the junction.

The same thing could be done using "Control track at trackmark" command and placing a trackmark on a piece of disconnected track near the crossing.
You would then use "Free track at trackmark. The numbers are <kuid:131986:180151> and <kuid:131986:180152>.

Regards - Trevor

 

[itareus]

This has been a thorny problem for a long time and there is no perfect solution (as yet).

Check this site (part 12) for a partial solution:

http://trains.0catch.com/tutorial.html

And also check out this thread (one of many), just to see how complex it can be:

http://forums.auran.com/trainz/showthread.php?t=48207&highlight=junction

I have been pondering on the idea that a "simple!!" rule that set the aspect of a nominated signal conditional to the direction of a junction (Trainz interlocking?) might go part of the way to solving the problem, but I have yet to have a go at Trainz Scripting so can't prove the theory!!

 

[colourlight]

Thank you Itareus for your input. It's given me something to think about. I am working on the Razorback Railway and being english I have given it a uk feel by using UK signals, motor points and rolling stock. I have changed some of the track layout to improve it from an operational viewpoint such as changing a lot of the single line sections to double track and some single lines in one direction only to increase track capacity. The need for running round has been eliminated and portals added for AI trains. I use up to 3 portals at each location. one for trains exiting, one for passenger trains entering and one for freight trains entering. Getting back to the subject there are two busy junctions where this problem occurs, Waggle and Altona. I,ll look at the various options you mentioned and take it from there. I appreciate your help, thanks. P.S. If anyone from the Razorback Railway reads this it is a great layout and it,s a pity Auran messed up your scenarios. By the way, purely out of curosity what happened to the BMS Colliery. Did subsidence cause it to disappear into the ground? lol

 

[itareus]

...Thank you Itareus for your input....

You are welcome. Just a further thought, it might be worth your while checking out:

ASB Crossover Controller,<kuid:76656:70001> by "Boat"

and

Junction Link,<kuid:122381:10003> by "Mizi"

Both on the DLS.

Neither is intended for the job but depending on the circumstances relating to the junction they may be of some help. Note: These are both "Objects" with functionality (as opposed to rules) - click on the (?) button and then the object after you have downloaded them and placed them on the route to set them up.

 

[stagecoach]

The ASB set up will allow only one train to pass through its controled area and will set signals to danger. The ASB will decide which train goes first so the branch may get priority over the main line. There is a rule that sets a signal according to the direction of junctions which ive used for a long time but not sure how I got it. Will look it up and let you know.

Edit Switch Signal Rule kuid:110532:60000 by James Thorpe

 

[itareus]

.........There is a rule that sets a signal according to the direction of junctions which ive used for a long time but not sure how I got it. Will look it up and let you know..........

Edit Switch Signal Rule kuid:110532:60000 by James Thorpe

Thanks for that stagecoach, unfortunately I have been unable to find this rule on the DLS (either via CM3 or the website with all boxes ticked). A Google search did not reveal anything (other than the fact that another Trainzer was also missing the same KUID).

Has anybody any idea where I might find it?

 

[stagecoach]

Has anybody any idea where I might find it?

PM me with an e-mail and I will pass it on. It states that it is free to pass on but not altered. Not sure he got around to putting it on the DLS.

 

[sparky15]

I asked this on another board but thought I might throw it out here too. It's kind of related if you cross your eyes and don't stare hard.

I'm having problems with AI locking junctions at meets on single track main lines. I played around with a rule to give an absolute stop to give a buffer between myself and the AI. Worked alright, not great. What I think I would need is a rule to trigger a diverge signal on an 06 signal from Jointed Rail.

The best thing I can see is getting out of the AI's way. I'm thinking if an 06 signal can be configured to show a diverge two blocks ahead, I could make it work. Basically an AI heading my way would trigger me to take a siding, putting me in the hole, until he passes, well before he takes control of the junctions in the block I'm in.

I would still need to control the junction myself, trying a trigger junction rule just messed it all up. Does anyone know of such a rule?

Dave......

 

[Kennilworth]

Hi

What is needed here is some form of decision making rule similar to the If...If Else...If End commands in the SCS2006 rule and the ability to have variables which can be set to whatever value you require. I use SCS2006 and the above problems are easily solved using the commands in the rule.

Both cases above could be solved by having a Yes-No variable to indicate if the crossing or single line section is occupied. If the variable is set to Yes then an approaching train would be issued with a command to Stop at Trackmark before the crossing. It would then go into a loop in the program which would check the variable every ten seconds until it was set to No when it would set a path through the crossing and continue on its way.

If the variable is set to No when it approaches the crossing then it sets a path straight through the crossing and sets the variable to Yes. When it has cleared the crossing it resets the variable to No.

In effect the variable mimics real life as it acts as a token to prevent two trains being on the crossing or single line section at the same time. Only one train can hold the token at any one time.

One of the main reasons that I started using the SCS2006 rule was the lack of control with the AI drivers and the absence of decision making logic for them.

I hope that what I have written is understandable. I am not particularly advocating the use of the SCS2006 rule but I am trying to highlight what I think is a major ommision from existing rules for AI drivers.

Regards

Brian

 

[ldowns]

I've found the Trigger Multiple Signals rule ([FONT=Verdana, Arial]116387:26:1) to work well for this and other situations where tracks cross but are not connected. You place a trigger on each track and tell it which signals will be set to red when it's triggered by a train. The signal goes back to its normal aspect once the train is no longer within the trigger radius.

There are a few signals that don't seem to work with this, apparently due to their scripting. Trial and error seems to be the only way to determine which ones they are.

--Lamont

[/FONT]

 

[itareus]

....What is needed here is some form of decision making rule similar to the If...If Else...If End commands in the SCS2006 rule and the ability to have variables which can be set to whatever value you require......

Brian,

I agree - such a rule (with variables such as "signal aspect", "junction direction", "section occupied" etc.) would have many uses in AI control and would be very flexible - for example with the double junction:

IF
Junction XXX Direction = Left
THEN
Signal YYY Aspect = Danger
ELSE
Signal YYY Aspect = Clear

(In the example above Junction XXX crosses a diamond and Signal YYY prevents a conflicting move).

Ideally the rule could be "nested" that is to say something like:

IF
Junction XXX Direction = Left
(AND) IF Section QQQ Occupied = True
THEN
Signal YYY Aspect = Danger
ELSE
Signal YYY Aspect = Clear

The above is not meant to be code syntax - if I could code in Trainz Script I would be writing the rule now, not talking about it !!