The sad part is that I've actually done something like this. It used to be a rite of passage for climbing at Yellow Creek, AL (one of the finest sandstone cliffs in the South, sadly closed now) to walk across an abandoned railroad bridge over an arm of Lake Weiss to access the cliff. As the line was abandoned, all of the rails and cross ties had been removed, so you had to walk one of the two 18" wide girders for more than 100 yds. ~75' above the lake. It's funny how many climbers were a complete wreck at the prospect. It was especially funny early in the morning with a hangover. If you camped there, it was common to rig a rope swing in the middle of one of the girders, so that you jumped standing over one of the stone bridge supports and you would drop, swing, skim the lake and just miss hitting the other bridge support. If you got the length of the rope right.
First time I saw it, I said, 'That's the dumbest f$#king thing I've ever seen', and refused to participate.
About midnight, after a substantial amount of ethanol and herbal fortification, it seemed like a capital idea. The cool part was crawling out on the girder, in the dark, to rig up. Steve couldn't make it at all, and passed out on the girder. I'm pretty sure I asked Greg to hold my beer and watch this. But I jumped, and I was right: It's one of the dumbest f$#king things I've done and not got hurt, and I'm a connoisseur of that sort of thing.