Wednesday, October 10, 2018

Electrical wars, Part 15

It occurs to me, in writing the title for this post, that it must say something about me and model railroad layouts, that I am up to the 15th episode in describing my efforts to conquer electrical problems of all kinds. But that is just how it has gone. For anyone interested in previous posts in this series, the easiest way to find them is to use “electrical wars” as a search term in the search box over at the right of this top paragraph.
     There were two electrical faults which showed up in my last operating session, one from some recent trackwork, but the other from track first laid (and powered) over 20 years ago.The event in more recent track occurred in a single rail within a three-way turnout, which had operated properly for several years, but suddenly became intermittently dead. This problem was easy to fix: I simply soldered a short wire to connect the offending intermittent actor, and the appropriate stock rail. In the center of the photo below, you can see the two ends of the wire because of its orange insulation. This will all be painted dark brown, of course, but I wanted to photograph it so it was evident what I did. (You can click on the image to enlarge it if you wish.)

In the background is the Common Standard No. 22 depot at Santa Rosalia on my layout, familiar to SP modelers as an American Model Builders kit (and a delight to build, as I described in a series of posts awhile back; the conclusion is at this link: ).
     The first of these problems, the straight track that has been in place over 20 years (actually closer to 30 years) was a slightly different problem. Try as I might, I cannot find a loose wire or cracked solder joint or any other explanation for intermittent power to this track. But whether or not there may be a  problem, the simplest procedure is to simply place new feeders to the track in the offending area. The arrangement of gaps and feeders are the same as in the second of two diagrams on a prior post (you can find that post at: ). I will repeat that description here.
     Here is how the layout was originally wired, with power routing through turnouts at the end of sidings. A full gap was cut at the center of sidings like this (using conventional symbols for gaps and feeders).

Especially if it is a long siding, it can become tedious to have to run down to the other end of the siding all the time, so that a turnout can be powered for movement in the middle of the siding. One also depends on the turnout effectively routing power every time. The simple answer, of course, is to replace the arrangement above with this:

     The first step is to cut the gaps, which I did with a cut-off disc in a  hobby tool. Then holes need to be drilled for the feeders that will be added.

Lastly, the wire feeds are soldered to the rails at each location.

     These additions should correct this track power problem, though since it has been intermittent during operating sessions, I can’t be certain yet. Next step will be to operate over the area as much as I can, and see if I can still obtain a failure. Of course, given the perversity of layouts (you know, of course, that they can smell fear), the next failure may simply wait for another operating session.
Tony Thompson


  1. Entered below is a comment sent by Lou Adler:

    My Ohio layout had an electrical wiring mistake that did not appear for 2 years after I started monthly op sessions. Showed up one night when three turn-outs were "properly" aligned to cause it. And it took 2 days under the layout to identify the problem. Go figure.

    And, there was the piece of track on my Arkansas layout that was never wired and stayed that way for over 5 years. It got power through the rail joiner which is a "no-no." No matter how short, I always have an electrical lead attached to every piece of track.

    Thirdly, regardless of siding length, I always gap 4" from the frog point at one/both ends and have the rest of the siding always "hot." Avoids the potential for a short if a loco is across the gaps that are in the center of the siding track.

    Finally, why gap the outside rails on the mainline and siding? Only the rails that are effected by the turn-out points need to be gapped. Less wiring and less potential for messing up.

  2. Thanks for the comments, Lou, all good points. On your last question, I don't always gap the outside rails, but in a sense it is another way of ensuring that every rail gets a feeder. I confess that in some places, rails are fed by the rail joiners being soldered to both rails, but I prefer feeders.
    Tony Thompson