SuperElevation - Laws of Physics and the FRA

I'd sure like to see someone with real track experience comment on the impact of the DRG&W practice and the FRA policy of removing superelevation from the curves of what is now the C&TS. In a post in another thread about the 497 El Coke made reference to the DRG&W removing superelevation on curves once the San Juan no longer operated. That sounds like a pretty major impediment to returning to San Juan speeds, especially since the C&TS is mostly curves. Don't know why this hasn't been mentioned in this thread.

The FRA rule is pretty clear. You can download Rule 49 CFR Part 213 Track Safety Standards from [www.fra.dot.gov] There is a formula on page 34016 for determining the maximum allowable operating speed through a given degree of curvature and adjusting for the elevation of the outside rail. Try out the formula; it has a definite effect on allowable speed. Seems pretty clear in the text of the rule that the FRA doesn't like much superelevation because of the stress it places on the inside rail with slow-moving freights (sound like the C&TS equipment and speeds?).

As Scott was saying, some boxes are pretty hard to get outside of -- especially when the FRA is defining the box.