DCC Wiring for combined Reverse Loop and Wye

[Liam_]

I am wondering how (or if) this layout section would be wired for DCC using the Hornby Reverse Loop Module?

The Blue is the reverse loop and the red is the 'wye'.

  -Cheers Liam

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[Chrissaf]

Since the blue track with the red line next to it, is common to both the blue reverse loop AND the red WYE. Then isolating the track with the red line and powering via a RLM will protect both the reverse loop and the WYE. Just note that this section of track must be longer than your longest train (loco PLUS wagons & coaches) else a rethink is required.

[96RAF]

The Wye when taken from the lower (outer) track is not a reverse loop at all - use the truck with tape on one side method to chase it round..

 

You enter from the bottom go round and then reverse and the truck comes out the same way it went in.

 

Only that blue bit next to the red line is a contra line.

[Liam_]

Since the blue track with the red line next to it, is common to both the blue reverse loop AND the red WYE. Then isolating the track with the red line and powering via a RLM will protect both the reverse loop and the WYE. Just note that this section of track must be longer than your longest train (loco PLUS wagons & coaches) else a rethink is required.

Thanks for your help.

Would I also be right in saying that I could instead issolate a section between where the two lines meet the lower right-hand point and a similar point horizontally left from that also ( longer than my longest train) and have my normal dcc power feed back from the main loop on the left?

[Chrissaf]

If drawing below is what you mean then yes that should work too in principle. Note that the RLM protected track (marked in green) must extend into both routes via the point on the right hand side, else the red WYE section will still be un-protected. The green bars across the track represent IRJs.

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[Fishmanoz]

That's a really interesting little conundrum you have there Liam, and Chris 's solution is fine, I'm not disagreeing.

 

But to explain for anyone yet to figure it out, there are 2 RLs here.  The first is just the blue loop.  The second is the red combined with the upper blue, so the upper blue is common to both the loops.  The simple way to isolate both loops is to put the isolated section in the upper blue as first shown, but it won't work if any train is longer than it.  So then we get to the green isolated section, which can be made longer than the upper blue and so accommodate longer trains.

 

The thing is though that the green is in fact 2 isolated sections, one for each RL, but happening to be contiguous.  The section for the blue loop is from the left end of the green through to the left exit of the RH point (from the right exit of this point there is no RL).  Then the section for the red/blue loop is effectively only the RH point.  It's easy to see that this is correct by doing the running a wagon around trick.

 

How can this work though as an isolated section must be longer then the longest train, must it?  Let's restate the rule, then we see how it works.  The rule restated is that train/s cannot be entering and exiting an isolated section at the same time.  It doesn't matter if it is the same train entering and exiting because the section is too short, or if different trains running close to each other do it.  In either case, the RLM will be trying to swap the polarity back and forth at the same time so won't be able to achieve it.  Stated this way, we can see that the RH point cannot be entered and exited at the same time, so meets the restated criterion.

 

Sorry, had to get that off my chest, I trust it hasn't confused.  Maybe Chris will draw it up for everyone showing the 2 isolated sections separately, the second one being just the point, then it will be clearer.

[Chrissaf]

Your explanation made perfect sense to me Fishy.......but then it would, wouldn't it.

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Note my drawing not up to my usual standard, so evidently done on the quick and rough & ready just to get an answer published quickly. I sense that Liam knows exactly what he is doing and is just looking for a 'second opinion' confirmation, hence my rough & ready replies. And relatively short ones at that, for me.

[Liam_]

If drawing below is what you mean then yes that should work too in principle. Note that the RLM protected track (marked in green) must extend into both routes via the point on the right hand side, else the red WYE section will still be un-protected. The green bars across the track represent IRJs.

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This is what I originally thought, yes

[Liam_]

@Chrissaf @Fishmanoz

I think I will go with what I originally thought, putting the isolated section at the bottom (including the right-hand point , of course) as this would acoomodate the length of all the trains I would be running round the reverse loop.

Now I think ill go over to Hattons and buy myself a R8238 reverse loop control module, as they are going for £12!

Thanks for the help, Liam 😀

[Dazzler down under]

Guys, out of interest, can you run any sidings off the green part of the reverse loop?

[RDS]

... can you run any sidings off the green part of the reverse loop?

 

Yes, they will have the same Electrical characteristics as the rest of the RL.

[Chrissaf]

Liam,

It really is best not to use the blue quote button, particularly if the post you are quoting contains an image. The image makes your answer post go back to admin for approval. And that as you can see above, just adds unnecessary delay, particularly at weekends.

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Use the 'Reply' text box at the bottom of the page and click the 'Green' reply button. We are smart enough to realise what post you are referring to in your reply. The 'Blue' button is NOT a 'Reply to this post' button.