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[Greenhornet]

IN THE AUGUST TRAINS, IT WAS SAID THAT THE WHEEL TO RAIL FOOTPRINT IS 1 SQ IN. FOR THE PAST 55 YEARS I HAVE KNOWN THE FOOTPRINT TO BE 1/3 SQ IN, OR THE SIZE OF A DIME. IS THE DIFFERENCE DUE TO LOADING OR WHAT? THANKS

[tomikawaTT]

In 55 years:

• Weight per axle has risen as car capacity doubled.
• Newer rail has wider heads than older rail.
• Wheel diameter has increased, resulting in more area with equal metal distortion.

Also, both the "Size of a dime," and the, "One square inch," wheelprint numbers are SWAGs.  EVERY wheelprint is a variable, since no two cars (even in unit train service) have exactly equal weights on metallurgically identical wheels rolling on physically uniform, identically supported rail.  Only (your Diety of choice) knows the EXACT footprint of a given wheel at a given time - and just as soon as that wheel rotates the conditions, and the footprint, will change.

Chuck

PS:  Please disengage your CAPS key.  All caps is considered to be shouting, which can be construed as impolite.