I was giving some thought to these trucks, wondering why high capacity cars (85 and 90 tons capacity) of the pre-war period all seemed to use clasp brakes while our modern 100 and 125 ton cars don't, and then it dawned on me... composition brake shoes, which, near as I can tell, were developed in the mid fifties. Prior to that the common brake shoe was cast iron, and there must have been a limit to how much braking force could be developed with eight standard shoes per car, and 70 ton cars must have been pretty much it. Clasp brakes, with two shoes per wheel, double the amount of brake shoe contact are and also equalize the forces on the journal bearings, which probably had a good effect on journal bearing life. Anybody aware of a trade press article on the subject?

Dennis Storzek