http://www.youtube.com/watch?v=XhgHrDbN4EU
Seen from the outside of the curve, lengthwise of the track, the stacks look like the Leaning Tower of Pisa. Note the comparison to the vertical support under the bridge.
I superelevate single track by twisting the subgrade, about 1mm across the rails. By prototype standards, that is moderate superelevation. In 1:80 scale, that's 80mm - 3 1/8 inches. In HO, it's still less than 3.5 inches - and can be simulated with the 1/16 inch end-of-tie shim previously mentioned. Sharp curves on high-speed lines may be superelevated as much as 6" across the rails, but such curves will also have a minimum safe speed for slower trains.
Chuck (Modeling Central Japan in September, 1964 - with superelevated curves)
Here's a LINK that may offer some insights or information. I didn't read it through, as I feel that the degree of superelevation for our models needs to "look right", as well as perform properly. My low speed line is superelevated, but it was added "by eye", with a train in place on the curves, until it had the appearance which I wanted.
Wayne
I've spent some time searching the forum and have come up empty-handed with regard to my quest for a table of track curvature vs. speed. vs superelevation of the outer rail. Reason I ask is that I am modeling a high speed, heavy duty, double track main line in the WWII era, and have just finished two major 72" radius curves, with 1/16th" balsa under the outer ends of the ties, and it looks too extreme. I had this same layout in operation several years ago, with the same balsa strips, but the track was Code 100 brass; now I am using Code 83 nickel silver (Micro Engineering flex track). I don't know whether my visual standards have become more conservative as I age (no political discussions intended), or I just plain don't know what the heck I am doing, but I don't recall any prototype photos showing trains leaning that far! The operation tests (0-5-0 push-and-pulls) seem to be OK, although a few cars need some kingpin tuning to avoid leaning over too far. I'm thinking ~.040" styrene strips would be a better shim than ~.063" wood (3.5" opposed to 5.4" at the tie end).
Anyone have a link to a real railroad chart? Thanks.