I did a cool job a few years ago. It was up at a local coal mine, open pit. They scrub off the spoil with this thing called a drag line, which is a big (very) shovel. They then go down to the coal vein and drill holes for explosives and blow it up. After that they go in with huge trucks and front end loaders and scoop it up and transport it by rail car to the plant. One of the drag lines, which are so huge, they can't be driven on tracks, was in need of a little accident investigation since the operator had managed to knock the wire ropes off the top sheaves (rollers or pulleys) and it costs many hundreds of thousands of dollars when that happens in lost revenue and repair. I installed four CCTV cameras on it including one at the top of the front bar which is like 200ft off the ground. It worked, and they found out why the wire rope came off. Fun job too. Here is a pic of myself and my tech standing in front of the SMALLER of the three buckets. The big one holds 30 full sized pick up trucks.... BTW this pic is where the shovel fell, it is almost half buried in the dirt!