Reverse Loop Question...

Discussion in 'FAQs' started by Lighthorseman, Oct 9, 2003.

  1. Lighthorseman

    Lighthorseman Active Member

    My new layout idea is beginning to take shape, and I have a reverse loop question for you electrical gurus. This is not a DCC layout, just a regular block-type setup.

    I'd like to have a point-to-point layout, with reverse loops at each end for occaisions when I just want to watch trains go by. (That seems to be fairly often, actually...;) )

    I am aware that they have to be wired differently somehow in order to avoid a short circuit, but I am essentially a complete reverse loop naif. Here are my questions.

    >1.) Can a train go continuously through these loops, or do I have to stop the train, and physically flip a switch to alter polarity or something every time that train gets inside the reverse loop?

    >2.) Am I going to have to get some sort of 300 dollar nuclear-powered (Rocket science degree required) switch gizmo thingy just to have continuous running?

    >3.) Would I, as an electrical IDIOT, be better off just running a hidden return track, completely avoiding all need for these two reverse loops?

    I would much rather have these return loops, as it would be really nice to be able to see the trains running through the layout both ways, but I wonder if something like this is beyond my abilities.

    Really looking forward to any help. :)
  2. jon-monon

    jon-monon Active Member

    Steve, IMHO, because I have not had a reverse loop myself, but I do understand them:

    Yes, you or an automated gizmo has to flip the switch, but the train needn't stop.

    Yes, if you want to leave it to run on it's own. And then what will you do with the spent nuclear fuel? You might have to/be able to rig one up yourself that's maybe even just powered by mere electricity :D :D :D I see a $25 used 486 laptop running linux and controlling relays throught its' parallel port :D :D :D
    Yes. Hidden area could double as a hidden staging area, or just storage during point to point ops.
    Then you might consider not hiding the return track, and calling it a point to point double main (dogbone), if that will work for your plans.

    Nothing's beyond your abilities, Steve, you can do it however you like, as long as you don't have to redesign the laws of physics. The question are, is it beyond your interest level and is it worth the learning it might take to design the system?
  3. Ray Marinaccio

    Ray Marinaccio Active Member

    I believe you can do continuous running through the loops by changing the polarity of your main line between the loops. You could have the turnouts controlled by relays to insure the propper positions of the switches or you can throw them manually. I think I saw another thread discussing this (can't find it right now)
  4. Ray Marinaccio

    Ray Marinaccio Active Member

    Actually, you could have the polarity of the main line between the loops controlled by the position of the turnouts. Some turnout motors would have the switch built in to them that you would need. Have both turnouts wired together so one is set for entering a loop and the other for exiting. You can throw the turnouts as the train is in a loop (or set up a sensor to do it automaticly)And run the train through without stopping. If I can learn how to work a drawing program I could draw a diagram (I'm not good with computers)
  5. shamus

    shamus Registered Member

    Here's a reverse loop diagram for you


  6. jim currie

    jim currie Active Member

  7. 60103

    60103 Pooh Bah

    Reverse loops

    To accomplish the reverse loop running, you need at least 2 reversing switches. One sets the direction in the reverse loop; the other is for the main line.
    As you approach the reverse loop, set the direction that you are going to go around it. When the whole train is in the loop, you (1) change the turnout so the train can leave the loop and (2) change the direction on the main line.
    You need to have the 2 reversing switches separate from any reversing switch on your power pack/throttle. You can use the power pack reverser for switching.
    Since you probably have two reverse loops (for continuous running) you have the option of using one switch for both or a different one for each.
    Using the switch machine contacts to reverse the mainline leaves you with a problem of wiring the second loop. You will also have a problem if you change the turnout on the reverse loop with the train on the main line.
  8. Lighthorseman

    Lighthorseman Active Member


    :eek: Yipes. :eek: Maybe I'll look into a hidden return track. :D

    Thanks for the input! :)
  9. Ray Marinaccio

    Ray Marinaccio Active Member

    Didn't mean to scare you. I guess wiring looks easy to me because of experience. Do what feels comfortable to you. Keep it fun.
  10. Pitchwife

    Pitchwife Dreamer

    Hi Steve
    It really isn't that hard. We had discussed it a little in the thread
    I have a setup like what you want planned for an area of my layout. basicly all you need is a DPDT relay and a couple of sensors. They can be as simple or elaborate as you want, all they have to do is to tell the relay when the train passes. In the picture the polarity of the mainline gets switched, not the loops. It also shows where the sensors should go. If you need more information let me know. Setting up some simple circuits is something that even a novice could handle.

    Attached Files:

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