Friday, February 19, 2010

The Double (Track) Cross

For the majority of readers who visit this blog (thanks, by the way), this post is of no particular use.

But I see this error over and over again on user-posted track plans, so if it helps only one or two folks before they permanently fasten down their track, it's worth it.

The top configuration in the drawing above is often seen on newcomers' double-track ovals and other areas where double tracks curve into a set of crossovers.

Because the tighter inner end curve feeds directly into an opposing crossover, it creates a possibly troublesome S-curve, especially when shoving longer cars through. The alternative arrangement on the bottom of the drawing offers the same routing flexibility but creates much gentler S-curves.

Note that the same problem can develop when newcomers place an off-the-shelf double-crossover too close to a tight curve, not realizing that one route creates a significant S-curve.

Yeah, I know it's kind of a basic point -- thanks for indulging me.