Wednesday, June 6, 2018

More sags in track to fix

As I described in an earlier post, there are a few areas on my layout where track has begun to sag gently below its intended profile. Given that parts of the layout have been in place over 30 years, I suppose this is not really unreasonable, though I don’t understand what may have caused these sags. The real point, of course, is to correct them, as I showed in that previous post (see it at: ).
     In that post, I used an ordinary carpenter’s wood chisel to drive under the track and into the roadbed, forcing it to rise. Carefully choosing the insertion points allowed me to entirely fix the problem in the area I illustrated. But in one of the comments to that post, Dan Smith suggested I would have been better off to use what is called a “splitting chisel,” because it doesn’t have as great a diverging blade (or as Dan put it, it’s not as “wedgy”). This was an intriguing idea, so I bought such a chisel. It’s shown below.

This is a Gedore tool, made in Germany by a well-regarded hand tool company, and can be found for sale on any number of internet tool sales sites. As Dan mentioned, it’s often in the range of 10 to $12 for a well-made tool like this.
     I did note right away a distinct difference between the two kinds of chisel. The wood chisel has a very sharp edge, and thickens considerably behind the edge. The splitting chisel has a 45-degree edge, not really sharp at all, but doesn’t thicken. One thing I wanted to watch in my next sag fix was to see which chisel did a better job for my problem. Obviously both chisels have their place, but which one would work better on these track problems?
     One annoying sag that needed to be fixed had developed at a point near where another sag was previously fixed (see link in first paragraph of this post). The previous sag was in the main line; this one is on the beginning of the branch, and not surprisingly, at a similar point in the benchwork, suggesting some structural origin. Anyway, although a short sag, it does affect steam locomotives, which can get all their drivers down into the sag, reducing tractive effort. It definitely needs fixing. In the photo below, you can see the sag beneath the ruler.

     As in the previous project, I began by driving a chisel underneath the track. But the splitting chisel, not being sharp, really cannot be used at the beginning. Instead, I again used the wood chisel to start an “incision” under the track. Once it was started, I tried extending it with the splitting chisel.

This kind of works, but I have to say that there is no real advantage to the splitting chisel. The reason is that the wood chisel actually isn’t driven so far inwards that its thicker blade comes into play. I did work with both tools, but found I could do all I needed with the wood chisel. Once again, I was able to use the wood chisel by hand (once the incisions were made) to wiggle enough under the track to get everything pretty much lined up and the sag removed.
     I then had to re-ballast and clean up the area of work, but that’s not anything different than any other track ballast work, so I won’t show that. Here again, I was able to remove the sag, essentially by wedging under the track to raise it up where needed. I have a couple of other areas on the layout that need attention also, and will now proceed to work on those.
Tony Thompson

1 comment:

  1. Boy, you move fast! Sounds like the edge of the splitting chisel needs to be sharper. But if, as you say, the taper of the wood chisel really does not come into play, then the splitting chisel offers no advantage.
    Maybe it would be useful for shaving plastic grabirons off O scale boxcars...