Two Reverse Loop Questions

Model Railroader Layouts and layout building
1

I have two questions about a potential reverse loop on my layout. See the attached track diagram.

  1. First question, does the track highlighted in red actually create a reverse loop? I’ve always assumed it does, but when drawing out this diagram it suddenly occurred to me that maybe it doesn’t. Can someone else verify?

  2. If this IS a reverse loop, what would happen if I put insulators at the two points marked by black lines? Obviously trains couldn’t run through the red track, but this is planned to be an interchange track where locals drop off and pick up cars from a “foreign” railroad. So the engines never have to go all the way through the red track, they just need to pull part way in to pick up or drop off cars. Would the insulated section in the middle work to avoid a reverse loop, assuming it’s short enough that engines never have to run onto it?

2

Nope, no reversing loops there, if you follow the track plan around and move across the red tracks you never change directions.

NHRF

3

No, It does not reverse.

4

When you isolate a section of track in your reversing loop you don’t want to span the end with cars or locomotives where the track is of opposite polarity if you have metal wheels in metal trucks. The metal wheels are usually insulated on one end where the axle is inserted in the wheel. So the non-insulated end has an electric connection from the rail through the wheel to the axle to the side frame to the second axle to the wheel to the track. When the the truck spans the gap of different polarity you get a short. With two gaps and dead track in the middle you can still get the same effect if 2 trucks on the same or different cars span both gaps at the same time. Metal cars can act as a circuit through the car body also. Plastic wheels can eliminate this problem, but they have other issues. This is why the isolated section of track in your reversing loop needs to be longer than your longest train.

A good book on wiring should cover this with pictures and diagrams to make it clearer. I have an older Kalmbach book and found it to be very good so I am sure the current ones are too.

Enjoy

Paul

5

It isn’t a reversing section, since the train would still be running in the same direction. What it DOES do is short-circuit one half of the total track length - which might make it a convenient way to make it possible to have a slow freight and a faster manifest (or passenger train) follow each other around in the same direction with minimum speed interference

Chuck (modeling Central Japan in September, 1964)

6

Thanks for the replies. I don’t know why I always thought this was going to be a reverse loop. Sure will make wiring a lot simpler!