When were these cars used?

[Bob C]

Hi, KentBy ! Will make a non-authoratative guess that none of these cars would have been around in the mid-fiftys time frame. The "Cube" boxes (whatever length) were just arriving in the early '70s, I believe, and were one major reason/result of the elimination of roof walkways and full height ladders from cars after about 1972. While D/F (Damage Free) cushioned sills/draft gear were around in the '50s, the modern units, extending several feet beyond the car end are too late for your target dates. The covered hopper, am much less sure about - seems large for the '50s (probably 100 net tons) - the unloading mechanism would also date the car, but I don't know what was when. I'm sure someone may bring better info - just don't have access to my data at present, and the memory fogs up some. :? Bob c