Track Loop Problem

[gothmanghost]

I'm having a big problem with the new loop I just inserted, namely, the computer won't go through it properly. If I place a Track Mark at the end where the track comes back on itself to a junction, the computer will drive it to there, but if i ask it to go somewhere else after that, it won't go through the junction and backs up all the way around the loop and back the way it came.

 

[j_maybury]

Just add a second track mark further up the line, if that failes inspect the juntion for brakedges or switches that shudent be there!

 

[gothmanghost]

Tried

I've tried putting trackmarks right in front of each other, but it still reverses back around where it came.

Also, I tried solving this problem by putting in Track Direction Markers, but it keeps saying 'No Path To Selected Destination' but the Direction Markers are all set right. And it only comes up this message when i tell it to go on the new loop. Other Direction Markers in the session are all okay and the computer does what it is told.

 

[j_maybury]

is the junction properly signaled? and have you checked for rouge point switches along the tracks?

 

[Bill69]

Hi gothmanghost,

Check the position of your junction levers. If the lever has been placed automatically it could be in the wrong place, move it away from the frog to the outside of the spline point circle. If that fails delete one arm of the junction then relay it and reposition the lever again.

Cheers,
Bill69

 

[gothmanghost]

Okay

I will try that.

P.S. The computer also will only go one way around the loop too and refuses to go the other way.

 

[j_maybury]

One more thing you my want to try

run a train manualy around the track and if it de-rails you have found the problem.

 

[stagecoach]

Nothing broken or wrong. This has been around from the very start of trainz. Because the train sees a clear route onto the single track it wont change the junction ahead, the same applies to entering the loop it wont change the junction because it can see the TM. Adding signals and extra TM's may work but in most cases they dont. The answer is you need to place an invisible branch line within the loop near to the entrance to create an invisible junction. Place a direction marker on the loop and set the invisible lever to the branch.

 

[gothmanghost]

Confused

Could you guide me through how to do that please?

 

[Dermmy]

Trainz AI drivers (depending on the version) will attempt to control two junctions in front of the train and one junction behind the train. In most circumstances an AI driver will not enter a simple balloon loop, the AI will stall at the entrance. The driver throws the junction (say) to the right to enter the loop, then looks for the second junction which needs to be thrown the opposite way to leave the loop. The problem is that in a simple balloon loop the junction to enter the loop and to leave the loop are the same junction and the AI cannot throw it twice. To get through you need to fool the AI into thinking there are more junctions than there really are.

Imagine your balloon loop is a circle with the entrance at 6 o'clock. Use any 'invisible' track and create two junctions, one at 3 o'clock and one at 9 o'clock. There are 'invisible' levers also, so in 'Driver' there is no evidence that the 'false' junctions exist. The invisible track from the junctions does not need to go anywhere and only needs to be a few meters long. I normally put a hidden End-Of-Track marker on it though to be safe.

The AI driver now throws the junction at the entrance to the loop, and looks ahead only as far as the first 'false' junction. The AI will not try to throw the junction to leave the loop till it approaches the second invisible junction, by which time it will have released the entrance.

For a first try it might be easier to set the 'false' junctions up with visible track and levers, then swap the track out for an invisible track when you have it right...

Andy

 

[paulzmay]

Hmmm - I've always done things a bit differently (not really prototypically I'm afraid) and never had a problem:

All of my loops use direction markers so they have one track each way. Each track has a signal at the beginning, and at the end. There are no signals on the single line. This works fine unless you get two trains going one way meeting one the other - then the rear train of the two can sometimes attempt to take the wrong route. Otherwise it works fine.

The other method described above (with the extra invisible switch - like catch points) is well described in another recent thread on this forum.

Paul

 

[Len2480]

I think if you lay the track all the way round in one direction ie clockwise or vice versa..starting with double track,then going single around the loop from one track to the other..you only need one track mark after the top of the loop...L

 

[gothmanghost]

Solution

I found a solution. I made the track start at one point of the line and loop back and join a separate part of the line so there were two junctions. Also, a note to everyone, putting Track Direction Markers too close to Spline Points or Join Points in the track can make them not work. I put them further up the Loop away from a Join and it worked.