Is there a 'rule-of-thumb' about how to design the inclination of track to produce prototypical superelevation? I have read that for HO, one should start with a 0.010" elevation of the outer rail at the beginning of a curve, then increase that to 0.020" after about a 12" distance, then after another 12" distance increase to 0.030" for the center section of the curve and then decrease back to 0" in a manner symmetric with the design used for the increase. But shouldn't the design depend on the curve radius?

Bob N.

My stab at this is any super elevation, if wanted, would be visually OK only on long sweeping curves (>=48in?). This is to represent counteracting the centrifical force of a train running at speed on this curve. For not-so-long sweeping curves there would be no need for this as the trains run a speeds that the centrifical force will not overcome the wheel flange lateral force on the rail.

So now that I got some physics out of the way, from a visual perspective, a transition into super elevation would be good. The amount would be a visual choice but remember that this application looks appropriate only on large radius curves. And, too much would introduce a potential closeline effect pulling long trains through this section. As for specific amounts, I can't give a number other than to say that it's in the eye of the owner and the radius of the curve.

__________________
Bruce (McToots) McElhoe
KAMRI President
and Web Site Moderator

There was an article in a recent (past 12 months)issue of Model Railroader magazine, specifically about superelevation on model layouts. If my memory is any good at this point, I believe there was a table of recommended shimming of the outer rail in increments similar to what Bob N. was refering to. I keep all of my MR mags but don't know which one it was in. If I can find it I will post the info.