The missing link is finding the cable. We have a defunct gravel pit area that was owned by several companies. While hiking the area I discovered a 3 inch steel braided cable that is hundreds of feet long. I had come to the conclusion it had to be a gravel bucket haul of some sort. Plus the concrete thats busted up.
Up near Alabaster MI theres a rig that goes out into lake Huron for gypsum (now shut down) long cable buckets etc to fill the freighters on the lakes. They have the cable supports still there.