I saw a .mpeg on http://www.nutz.org of a man who had both arms tied to back to back jeeps. When the vehicles drove off one of the man’s arm was ripped off. OUCH!
Not sure whether it would be OK to post the link, but you can find this by searching at Snopes. (There’s a picture that you can see only by putting your mouse pointer over a blank area on the page, so you don’t have to see it if you don’t really want to. It’s not that bad, as gory pictures go.)
Ive seen the tug-of-war arm loss pic. Unfortunatly, it comes without technical data. But it is good to be reminded of, and demonstrates that if you fell very far off a bridge with a rope around your arm it would probably come off, which was the point. It, and a lot of other grusome stuff can be found at rotten.com
I’m not an engineer but I think you are possibly making a major error in one premise of your setup. Unless you are using steel cable a standard, high quality mountain climbing rope with 81 meters played out is going to have a fair amount of stretch if shocked with a 70kg weight falling at 31 m/s coming to an abrupt halt.
Dynamic ropes (used in mountain climbing) have a static stretch of 6% to 8% under load which means that the rope will be acting like a spring and stretching during the sudden deceleration for approximately 5 to 6.5 meters beyond of its total, non-loaded, 81 meter length. It may have enough stretch, in fact, to completely prevent the dismemberment you are concerned about.
http://www.sportextreme.com/Se_Shop/HTC/Climbing/Rope/Rope.asp?KategoriID=211