[Stonewall Jackson]

One of my friends used to do this back when he was young and dumb. One afternoon he was about six hundred feet up and he slipped. Fortunately he was harnessed in, so he only fell about twenty feet before stopping.

The main problem then was the fact that he was swinging at a pretty good rate of speed right beside a huge metal tower. He had arm guards on his forearms (they're intended for situations just like this), and was able to use them as shields to keep from smashing his face into the tower. He had some nasty bruises, but was otherwise okay.

[csense]

Fortunately he was harnessed in...

I'm just guessing, but I'd bet they have two security lines, or whatever you call them, that clip on to the structure, that way you're always secured as you go up. I know I wouldn't do it without two.

[semaj]

Your friend was fortunate, even a short drop when harnessed, can leave you severely injured, as the stopping force is in the thousands of pounds of force. I used to free climb towers in another life, until I went to a rescue climbing course, and learned how to do it safely. Rule number one, is to always have at least one tie-in at all times to the tower, that way even if you do slip, you don't go all the way down.