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Return to hobby

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  • Member since
    April 2021
  • 1 posts
Return to hobby
Posted by Darrell F on Friday, April 23, 2021 3:02 PM

Greetings to all. I am an old(er) guy returning to the hobby after a long absence. I have noticed so many changes that it is impossible to mention them all. A little history. I had a small 4 x 8 ho layout some 30+ years ago, a simple layout for my youngest son and I to build and operate, (him the operator,me the builder), just a standard loop around with a small yard and a couple of spurs for industries, small transformer and about 4-5 atlas pwered snap switches, about 6 diesel locomotives, (4 were dummies), and about 20-25 cars. Now that I am retired I would like to take up the hobby again but like I said before, so many changes mostly in the field of electronics etc which I have no knowledge of. My youngest grandsons have come across some of the engines,track,cars and buildings of yesteryear and would like to see it up and running again. So recently I decieded it would be good motivation to get back into the hobby again. I had a room that I  cleaned up and got to work building a layout for the boys and myself, being that it is quite likely that it will be my last one, I went with one that was larger than my old 4 x 8. The benchwork is built (I impressed myself with the finished product), and the track is in somewhat in place, now here is where hopefully you all come in. I have all kinds of problems with electrical (dc). I may have created what I have researched and found out may be a reverse loop,this may or may not be a fact, but more so, I have no idea where it may start/end. I would wonder if I were to draw up my plan and post it if someone would be able to help me out. I (we) would be gratefully appreciative. Sorry for the long winded story, (but like I said I'm retired now so have the time) Thanks again.                     

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 20,207 posts
Posted by MisterBeasley on Friday, April 23, 2021 5:47 PM

Sure, post away.  There's a thread on posting pictures and diagrams in the General Discussion forum.  Read that and come back with questions.

You're new, so your first few posts will be looked at by moderators to make sure you're not trying to sell vinyl siding.  That will pass after a few posts, but your first few posts will be delayed. 

Questions about reverse loops usually end up in the Electronics an DCC forum.

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 22,956 posts
Posted by selector on Friday, April 23, 2021 7:27 PM

Welcome to you!

We'll help all we can, including to urge you not to limit yourself for any reason, least of all due to your advanced age.  Yeah, a lot of us are old(er) as well, and we know that it can bring some distinct limitations and challenges, such as bending down and getting under a bench to fix some wiring...or just to install it. But when you say this layout will probably be your last, don't bet on it! Unless we hit the jackpot with this one, you will probably want an improved version before a year or two, so think what you can do maybe to incorporate this build into a new one, or at least to recover a lot of the expensive materials that you don't want to replace.  Trust me, if this build gets old quickly, and there's always that danger, it will be because you have learned lots, including what bores you about model trains.

Post some ideas, and we'll help as and when we can.

Reversing tracks can be loops or 'wyes', any place where one rail makes contact with a rail that is fed the opposite phase/polarity somewhere else along the same contiguous length. If you could take a decent photo and post what you have, it should be quite clear where you might have a short taking place, almost always at a turnout (switch).

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 8,433 posts
Posted by BigDaddy on Friday, April 23, 2021 9:47 PM

Welcome to the forum.

A large block of text, like your post, is hard for some of us to read.  Fortunately your generation learned punctuation and capital letters, while later generations did not, but some paragraphs would help.

Posting pictures in this forum is unlike any other.   You have to follow the directions here

One trick about reversing loops is to imagine one side of a box car is white, the other black.  As you look at your layout from the side, if you can see the white side and the black side on the same piece of track, there is a reversing section.


COB Potomac & Northern

Shenandoah Valley

  • Member since
    July 2006
  • From: Bradford, Ontario
  • 13,516 posts
Posted by hon30critter on Saturday, April 24, 2021 12:09 AM

Hi Darrell!

Welcome to the forums and back to the hobby!    Welcome

The easiest way to prove that you have a short in the track plan (if you aren't sure if that is the problem) is to use two different coloured markers to follow your rails around a layout drawing. If there are no reverse loops then the colours should never end up on the same rail, i.e. the red rail will always stay red and the blue rail will always stay blue as you follow the rails around the drawing. If your red rail runs into the blue rail, that shows you that you have a short.

The next step is to decide where to put a reversing section so that you can change the track polarity at the point where the short occurs. Sometimes it is obvious. Other times it is not.

The usual method in DC is to use a DPDT switch which will flip the polarity of the track outside the reversing loop when a train is in the reversing section.

If you can post a drawing of the track plan we can suggest where to put the reversing section(s).


I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    July 2006
  • From: Bradford, Ontario
  • 13,516 posts
Posted by hon30critter on Saturday, April 24, 2021 12:39 AM

Hi again Darrell,

This explanation may help:


I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    October 2020
  • 2,065 posts
Posted by NorthBrit on Saturday, April 24, 2021 4:11 AM

Hi Darrell.   Welcome  Welcome on board.



To the world you are someone.    To someone you are the world

I cannot afford the luxury of a negative thought

  • Member since
    June 2020
  • 3,597 posts
Posted by Lastspikemike on Saturday, April 24, 2021 9:30 AM

Sounds very similar to my experience starting a year and a half ago.

Check out DCC at some point. It's pretty good and easier to wire and to operate.

You can wire for DC using double isolated electrical blocks and then easily convert to DCC at any time.  

Be aware that locomotives are very atttactive purchases and cost a lot. Buy dual mode DCC from now on. You will want to run DCC eventually.

The easiest way to handle a reversing section on a DC layout initially is to disconnect the one piece of track that connects the opposite rails. At least then your layout will run.

Then ensure you have a least one separate pair of power feeders to the entire section of track that will be a reversing polarity problem. If you connect more than one pair of feeders to that track section make sure they are all in parallel, I.e. connected red to red and black to black. You'll notice that at one end of the reversing section the polarity of your feeders will look wrong and it will be. The red rail connects to a black rail at that point. This will be at a turnout. That is one end of what will become your reversing section. Fit isolation track joiners to both rails at some point between that turnout and the reversing section.  That's Part one.

Trouble is, when a locomotive crosses those isolation joiners its metal wheels and multiple power pickups will cross those isolated joints  and short out the layout.

Part 2 is creating a long enough section of isolated track with separate polarity control to hold an entire train (unless your rolling stock all has plastic wheels). So, tracing back from where the first isolating joiners are fit another pair of isolating joiners behind the end of the train, or as far back from there as you wish up to the turnout that created the reverse polarity problem.   

Part 3 is disconnecting all those power feeders within that reversing section from the powerpack and wiring them all in parallel to the output side of a DPDT switch (double pole double throw), connect one end of the same DPDT switch to the powerpack power feed. 

Part 4 is to cross wire the DPDT. The normal way is to connect each of the red to the black at the end of the DPDT where tgecpowrroack wire are connected diagonally across the DPDT to the opposite terminals at the end with no output connections. 

Part 5 is to realize when to change polarity of the main line. Your train travels across the first pair of isolating joiners and the DPDT is set to match that polarity (if the train stops, throw the DPDT) . When the train is entirely within the reversing section, beteeen the two sets of isolating joiners then throw the powerpack reversing switch.


Alyth Yard


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