How to handle overlapping return loops?

[nickelplate759]

Well, it is and it isn't.  If you treat the track as a 2D topology, then it really does reduce down to the oval with internal crossovers (leave out all redundant paths and branches).  But yes, the actual track plan has a lot of finicky little details.

I appreciate all the advice.  I'm going to start by checking out the Atlas crossing and see if the two legs are electrically isolated.

This is my first try at a DCC layout, if it isn't obvious.   Any advice on the DCC reversing unit itself?  Are they fairly generic?

[jagged ben]

Well, it is and it isn't.  If you treat the track as a 2D topology, then it really does reduce down to the oval with internal crossovers (leave out all redundant paths and branches).  But yes, the actual track plan has a lot of finicky little details.
...

Well, I would consider the extra route through the yard to be a significant schematic difference.  You've really done this...

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One has to switch back twice through the yard to follow this additional route.  That makes no difference electrically, although it's interesting that it basically nullifies any worries about train length on that route because the switchback in the yard physically limits the length. 

With that said, you have dealt with the additional reverse loop efficiently by including 'D' in the reversing section.  In other words... good job!   

One other comment, going back to your original concern about train length.  I've marked the shortest route through your reverse, which seems possibly not long enough.  You could make the shortest route longer by including both tracks beyond the turnout in the reversing section.

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[nickelplate759]

Well, I would consider the extra route through the yard to be a significant schematic difference.  You've really done this...

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One has to switch back twice through the yard to follow this additional route.  That makes no difference electrically, although it's interesting that it basically nullifies any worries about train length on that route because the switchback in the yard physically limits the length. 

With that said, you have dealt with the additional reverse loop efficiently by including 'D' in the reversing section.  In other words... good job!   

One other comment, going back to your original concern about train length.  I've marked the shortest route through your reverse, which seems possibly not long enough.  You could make the shortest route longer by including both tracks beyond the turnout in the reversing section.

Actually (because I love this stuff, not 'cause it matters here), that route through the yard is really just parallel to F, and can be removed for the analysis of where the reversing sections are.

That said, I do appreciate your suggestions.  I need to decide if I want to maximize the length of red loop length as you suggest, or maximize the other loop (around the yard), which the current version tries to do.

[nickelplate759]

I'm realizing I don't know enough about DCC layout installation.   
For example, I just realized I probably need multiple blocks with circuit overload protection, not just a reverser.
I also realized that there are more choices for DCC control stations than I realized.

I'd appreciate suggestions on reading to learn more.

[peteski]

There is not need to install multiple overload protection circuits (or power districts) on a DCC layout. Well, that depends on the size of the layout and how you want to operate it.  If you have a small switching layout and run it by yourself then there really is no need for multiple power districts or overload protection (the DCC booster already has a breaker built-in).  But if you have a large layout with half a dozen operators running multiple trains then dividing the layout into multiple blocks (with each on a separate overload protection) makes sense operationally. You also need to estimate the amount of current which will be needed t run the layout.

And yes, there  are many many brands of DCC systems and even multiple choices of boosters for a given brand.  You need to decide which DCC system you prefer and calculate how much current your trains will consume.

[jagged ben]

Actually (because I love this stuff, not 'cause it matters here), that route through the yard is really just parallel to F, and can be removed for the analysis of where the reversing sections are.

In the same spirit, I'd point out that's not entirely true.  There's at least one combination of sections --  (A+E+F) -- that handles the issues in the original schematic but not with the additional route considered. 

But again, you've got something that works, so at this point it's moot.   I don't think you really needed our help all that much.   

[jagged ben]

On the power district question, I think it depends a little if you intend to have more than one train running at a time.    It's not striking me as a multiple operator layout.  But, for example, I could see myself leaving a train running on the main loop while I did some switching or a run up the branch line.  In that case, if you didn't want a derailment or a turnout thrown the wrong way to shut down the continuous running on the main loop, you might want the yard and/or the branch line on different power districts. 

A unit like the digitrax PM42 would let you have four districts: 1) main loop and staging (unreversed) 2) reversing section 3) yard, 4) branchline.  Without costing four times as much as just the autoreverser.   It'd be more of a luxury than an necessity, but perhaps worth considering.   

[nickelplate759]

The layout is small, but certainly big enough for 2 operators.  I fantasize that a computer (via JMRI) might also be an operator...
So multiple power blocks is probably a good idea.

Thanks!