Where should I gap my reverse loop?

Model Railroader Electronics and DCC
1

Hi everybody,

I am building my first large layout (12’ x20’ with a 12-foot staging extension. I have planned a reverse loop created by a cross-over from westbound to eastbound track (see the attached simplified track diagram). I’m not sure where to gap the rails for the reverse loop. I will be using DCC and an auto-reverse module. Any suggestions will be appreciated.

Simplified Track DiagramThanks!

2

in general, you would like the reversing section to be longer than your longest train so that when a train has completely entered the reversing section the polarity can be aligned at the exit end without worrying about any metal wheels causing a short at the entrance end.

in your case both rails at each end (4) of the section identified as “long enought for a 3-locomotive consist” should be gapped near the turnouts.

3

There are several ways to accomplish your objective depending upon where you want the reversing section and how you are willing to wire your layout.

You could treat the right side of the layout as the reversing section or, alternatively, you could treat the left side of the layout as the reversing section.

If you follow a conventional wiring pattern with the outside rail all around the layout as one polarity and the inside rail all around the layout as the other polarity, the point of reverse polarity will be where the crossover turnouts connect. The rails need to be gapped at that point and, in addition, two more sets of gaps will be needed elsewhere to completely isolate the reversing section. It will be up to you to pick the right side or left side of the layout for that purpose.

Another way to deal with the reverse polarity issue would be to wire the crossover and adjoining tracks with matching polarities and then isolate the top or bottom of the layout as the reversing section. This arrangement would require two sets of gaps to isolate the reversing section.

Rich

4

I’m not sure if it matters with DCC, but I would suggest that wherever you choose to have your reversing loop, your staging yard should enter the main line outside that reversing loop. It does matter with a DC wired layout. (it can be overcome but it complicates the issue)

Tim

5

Check out the link I have here to an article I wrote a while ago. The track plan is not dissimilar

http://yourmodelrailway.net/view_topic.php?id=10671&forum_id=6&highlight=sunil#p203690

Hope this helps … if you want a drawing tailored to you, PM me with your email address!

Cheers from Australia

Trevor

6

Yeah, that could work, as Greg and I mentioned in our earlier replies. But, since the crossover section of track is only long enough to accommodate a 3-locomotive consist, it may not be sufficient to hold the OP’s longest train, assuming metal wheels on the rolling stock, and a dead short may occur.

Rich

7

I think the easiest way to handle this would be to create 2 reversing loops. Gaps marked in red.

8

You really only need one reversing section. The rest of the layout would be the non-reversing section. No need for a second reversing section.

Rich

9

Oh, I think I get it now. For example you could put the gaps at each end of the two 180° curves, make the curves “the rest of the layout” and make the entire middle the reversing section.

10

Exactly. You could isolate the crossover as the reversing section…or the left loop, or the right loop, or the top, or the bottom. It all depends upon where you decide to place the gaps and what location you prefer for the reversing section.

Rich