Starting in Feb 1952 I was an operater on this swing bridge, and had this job on and off until 1960. When I first started, when closing the bridge after a boat had passed thru, the operaters had to walk from the cabin to the west end of the bridge, go down a ladder, step on a small platform under the rails just above the river to check to see that a huge round bottom pin had dropped a small distance into a slot, before we went back to the cabin to force the rails all the way down. If we closed the bridge to fast the pin would slip over the slot... I would like to know if that pin was cast iron or steel.... Sometimes when checking this pin location, it could be scary, if it was raining, snowing, and dark outside.