I think these guard rails may be positioned as they are to carry the wide tires of bald drivers on the locomotives. It's usual practice to have a "flange-bearing" guard rail on the gauge of the inside rail, which serves the purpose of pulling the flanges of wheels on the outside rail away from the rail, both to reduce wear on the rail and flanges and to prevent the outside wheels from climbing the rail. Such a guard rail would be close to the running rail so that the back of the flanges of wheels on the inside of the curve would contact it. That does not appear to be the case in this photo, and the guards rail on the outside of the curve doesn't appear to be positioned to contact the flanges, either.
Edited 1 time(s). Last edit at 12/10/2011 08:06PM by Wayne Laepple.