Tuesday, July 4, 2023

Trackwork wars, Part 6

 From time to time in this blog, I have related the challenges of maintaining trackwork (nearly all of it installed long ago). “Maintaining?” you may exclaim. And yes, most of it is indeed commercial track components, yet maintenance is still required. 

An area that continues to baffle me is the change in gauge of commercial turnouts, particularly Peco turnouts. This concern goes back some years, and has not ended (see my initial attack on this, in a 2018 post: https://modelingthesp.blogspot.com/2018/07/trackwwork-wars-part-2.html ). In each operating session that I host on my layout, I keep notes of any and all problems encountered by crews. Lately there have been some problems with track gauge, again.

All I can do is go around the layout, checking not only the track switches where problems occurred, but all switches. Of course the NMRA gauge is my friend in this. Here I’m confirming the corrected gauge in the yard lead at Shumala.

When a problem is found, almost always tight rather than wide gauge, I either use pliers to change rail curvature, or use files to widen the gauge.

[I should mention that I have always been very careful to check gauge in commercial switches before installing them. Back when I was first building extensive trackwork, over 30 years ago, the standard of the day was the Shinohara line, and I found, as did many others, that about one Shinohara in ten had distinctly tight gauge through the frog. You couldn’t fix it. They simply had to be discarded. Ever since, I have very carefully checked every switch before installation. So I am confident that the track gauge problems I describe in this post occurred after installation.]  

One area of continuing issues is the three-way Peco switch in front of the Santa Rosalia depot. I have had to correct the gauge several times. Here’s a check after correction:

Another place that was fine for years and recently acted up, is the house track switch at the Ballard depot. Again, gauge had to be corrected. This is an old Shinohara switch, which certainly would have been checked before the original installation. Now it’s fine.

Another area of past trouble is the switch off the branchline main to Track 7 at the rear of Ballard. There was only a short segment out of gauge this time.

Lastly, a Peco switch for which I have had to widen the gauge through the frog at least three previous times, and now it needed a bit more widening. It’s in my East Shumala area, the switch that gives access to the two industry tracks.

I continue to be baffled as to what is causing this. Where I live, Berkeley, California, we have neither winter nor summer temperature extremes, nor extremes in humidity, that might affect benchwork as well as track. Perhaps the plastic into which the rails are molded in commercial turnouts is shrinking for some reason.

So in summary, even on a layout with some areas that received track two decades ago, and none less than five years ago, trackwork needs checking whenever an op session has found any problems. That was how the areas shown in this post came to my attention. So I can’t say “lesson learned;” it’s more like “lesson learned one more time.” But I’ll be ready for the next op session.

Tony Thompson


  1. I remember a posting (long ago) on a DCC-SIG about kinked flex track in a yard and wonder if this is a similar problem.
    Model rail is manufactured by drawing a rod through a die and as a result the rail has tension in its internal structure. The thought was that greater DCC amperage and voltage applied to the rails caused the tension to adjust, causing kinking.
    A recommended solution was to pre-tension the rail by using an 18 volt 5 amp power supply to drive a #1151 taillight bulb through it for about 30 minutes before laying the track.
    Perhaps the smaller rail lengths used in turnouts kink to a lesser degree and show up as your track gauge challenge?

  2. Thanks for an interesting comment. But I haven't had any kinking. And the amperages in HO scale locomotive operation seem to me, as a metallurgist, to be unlikely to alter internal rail structure. Lastly, since my problems invariably seem to be REDUCTION in gauge at turnouts, I'm not sure how rail stresses could cause them. But I'll think further about this.
    Tony Thompson