Sidings on a reverse loop

Discussion in 'FAQs' started by YmeBP, Jul 17, 2007.

  1. YmeBP

    YmeBP Member

    I've got a figure 8 w/ a siding branching off it and i'm wondering how to wire the siding? I would think i would want the siding to be the same polarity as the track it diverges from, but what if i have a train in the reverse loop and on a siding at the same time? How would i deal w/ that situation?

    It will be dcc when i'm finished.
  2. bigsteel

    bigsteel Call me Mr.Tinkertrain

    I'm in no way an expert but it sounds like you'll need to isolate the siding from the reverse loop and maybe wire in an automatic'll have to wait for the more experienced electricians on here for a more in depth answer.--josh
  3. 60103

    60103 Pooh Bah

    I'm not sure just what you need. If the sidings all connect to the reversing section, you could just keep them wired to it -- when you go DCC you can wire the sidings to the output side of the reversing module.
    Or you could wire them separately with the same direction control as the main layout -- have a double gap at the turnout that enters the siding. Then you can run the independently and get the reverse module only when you go out again.
    In DCC it won't matter about the reverse loop because the module flips the polarity so fast the loco doesn't notice and the polarity does not affect how the loco runs.
  4. YmeBP

    YmeBP Member

    I had a feeling polarity wasn't as important in dcc but i wanted to be sure. I'm shifting the wiring from dc to dcc and i really should have made better notes :) when i first wired it up hahah.

    Thanks for the help, i'll post progress in my 4x8 layout thread.
  5. slufoot733

    slufoot733 New Member

    60103 is correct. Here's a little test. If you have a dual mode loco (runs on DC or DCC) place it on a short track powered by DC. Start the loco. As it travels down the track throw the reverse switch on the DC power pack. The engine will continue to run in the same direction it was traveling. To reverse it you must shut the power off, then throw the reverse switch on the power pack, then turn the know to feed power to the engine. What's happening here is the change in polarity is compensated for by the decoder. The decoder knows it was heading 'east' so it continues east. Whent he power is shut down then the decoder waits for a new command, in this case a change in polarity, which tells the decoder it should 'go the other way.

    In otherwords, you should have no problem with your siding being powered the same as the loop. But, if you feel better about not switching the polarity on the siding then insolate it and wire it with feeders from the main bus.
  6. steamhead

    steamhead Active Member

    Maybe I missed something...but a figure 8 does not have any reverse loops....It's just one track crossing over itself...
  7. YmeBP

    YmeBP Member

    I have a figure 8 inside an oval, check it out here :):

    I should have been a little more descriptive hehehe. sign1
  8. steamhead

    steamhead Active Member

    Whoooo...!!! Now I see...Not one, but 2 reverse loops..!! I figure the siding should be part of the reverse loop. but if you do any kind of switching there, you'll be crossing into the main line quite often...Do you have automatic reversing units..?
  9. YmeBP

    YmeBP Member

    Not yet, but i will, right now i have it blocked from left to right, so saw the oval/8 in half at the "x" and that is pretty much how i have it blocked.

    I figure i will have a passenger station at the end of the shorter siding and industry at the end of the other 2 sidings so a little traffic on the mainline will make my kids think about who get's right of way on that track segment.

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