In a short story I'm writing, a scene has a policeman running for his life from a couple of crooks. They're at an abandoned factory/mill/plant, and the cop makes his way up a few floors of a building, where he goes out a window and crosses over to another building. I've been looking at photos of factories and see an amazing network of pipes and wires. But what could I use at a factory that would support the weight of three men on a suspended platform running from one building to another? These don't really have to be buildings, and it could be any plant or factory. Probably a chemical plant. I just need to get them crossing on a suspended platform between two large structures at some kind of abandoned industrial setting. This photo is a good example of what I have in mind: http://www.dreamstime.com/chemical-plant-image6400423 Any idea what those platforms are?