It is important to remember these numbers are not cast in stone. I have seen both 2101 and 614 turned on 85 pound rail in Martinsburg, WV several times. I think both of these engines have axle weights in the upper 60,000 pound range. In Fayetteville, NC CSX runs daily a SD-40 as the yard engine which runs most of the day on 70 and 85 pound rail moving cuts of cars including 286,000 pound cars. They also run the heaviest EMD and GE whatever those ugly new locomotives are on these tracks daily with relatively few broken rails. To say the track is marginally maintained is an understatement.
On the Aberdeen and Rockfish we still have a siding with 60 pound rail in Cliffdale. When we were storing loaded plastic cars a few years ago this track was full of 286,000 pound cars that were switched pretty frequently. We were running those cars to Cliffdale on mostly 75 and 80 pound rail at 25 mph on grades as steep as 3 percent. I remember no broken rails during these moves. In our records there is mention of a siding being used to double over coal trains in the sixties with GP locomotives as heavy as a GP-38 that they eventually replaced the 35 and 40 pound rail with 80 pound rail.
The bottom line is you can run just about anything you have on these rail sections if they are halfway supported. The smaller, older rail does not seem to be all that brittle. What it does not do as well as larger rail is hold gage and surface. You will have to replace the ties more frequently and in larger quanties under small rail and surface the railroad more frequently but you can run trains on it.
John Bohon
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