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"A simple track Question:

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  • Member since
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  • From: west of Portland Oreg.( the city of Roses
  • 599 posts
"A simple track Question:
Posted by TrainsRMe1 on Monday, May 14, 2012 11:00 AM

hey fellow Mrrder's,

I have a question, I building a returning loop at one end of my layout,it's coming out as the main line from a yard with a crossover but it WILL NOT be a ballon track, it will just go back as double main line into the yard, the double main line won't meet until the other side of the yard, will this still be considerd a reversal loop????? thanks... Tranisrme1

  • Member since
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  • From: Enfield, CT
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Posted by Doc in CT on Monday, May 14, 2012 11:23 AM

Is this an electrical question?  If so where is the polarity reversal occurring. Functionally, I would think it depends on how the loop is used.

Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/

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Posted by RetGM on Monday, May 14, 2012 12:06 PM

Trains:  Don't quite visualize the layout you describe, but this will answer your question.  Get two different colored pencils and trace the North rail with one and the South rail with  the other.  Doesn't matter where you start.  If one color meets the other at any point on the same rail,  IT"S A REVERSING LOOP and must be wired as a separate block (isolate both rails at both ends of the block, which should be at least one  train length long to prevent problems with shorting across the "joints".

Happy modeling!!  JWH

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Posted by IRONROOSTER on Monday, May 14, 2012 1:07 PM

This sounds like you are building a reversing loop.  However, a problem only occurs when you connect back to the track that started the loop (or a track connected to it).  Somewhere before that happens you need an electrically isolated section of track that should be as long as your longest train.  This track can be partially or wholly in the loop itself or along your main line as long as it occurs before the first connection (crossover, etc.) back to the original track.  This isolated section is your reversing section regardless of whether it's in the loop or not.

If you haven't already, pick up a wiring book - Kalmbach has a basic one for DC and one for DCC as well as other electrical books.

Good luck

Paul

If you're having fun, you're doing it the right way.
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Posted by Train Modeler on Monday, May 14, 2012 2:12 PM

Trainsme1--sounds like a reversing loop where after the yard going back onto the mainline in reverse direction you will need a polarity change at the mainline turnout.   DPDT switches will work or PSX-AR if DCC.

Richard

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  • From: Sierra Vista, Arizona
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Posted by cacole on Tuesday, May 15, 2012 7:48 AM

Take a cheap boxcar and paint a large + sign on one side, and large - sign on the other.  Push it around your layout.  If the plus side doesn't suddenly encounter a piece of track that should be the minus side, you have no reverse loop.

 

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Posted by Anonymous on Tuesday, May 15, 2012 8:26 AM

If it looks anything like the following, it is a return loop and will short out!

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  • From: Canada
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Posted by cv_acr on Tuesday, May 15, 2012 10:58 AM

TrainsRMe1

hey fellow Mrrder's,

I have a question, I building a returning loop at one end of my layout,it's coming out as the main line from a yard with a crossover but it WILL NOT be a ballon track, it will just go back as double main line into the yard, the double main line won't meet until the other side of the yard, will this still be considerd a reversal loop????? thanks... Tranisrme1

(Emphasis added.)

Yes.

Anything that links back and allows the train to end up turned the other way is a reversing section and will short out if not wired properly.

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