InsaneJournal

There's a mountain near here where they put you in a harness attached to a metal wire 15 metres off the ground so you can use gravity to speed down 800 feet. Which isn't really very long. The longest ones are over two kilometres, but they're all quite a distance away in comparison to the size of the planet, which is a pity. I don't think an 800 foot line would be long enough to get up to the speeds recorded on those. I suppose you'd need to find a way to either support the line at points between each end without interfering with the pulley connection or set it up high enough to counteract the sag from the weight of the wire, which would definitely increase your production costs.