I have read that some railroad cranes had "rail clamps" My guess is that these are some sort of stabilizing chains securing the crane deck to the rails. I wonder if the Pile drivers had something similar. There are pics of the OB laying on its side, so must have been an issue.
I did a google image search on railroad pile drivers and saw lots of pics of top heavy machines perched on the end of spindley trestles. Pretty cool stuff. Not a job I would like!
Standard gauge but must be similar. I don't think I would like to operate that thing!
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