I Broke Amsteel 7/64
I'm pretty heavy--about 370 lbs. I've been dropped in the field twice--both times by situations outside the area of this thread (fisherman's knot slipped, crushed toggle when I used a "found" stick). However, the one time that I straight out broke some Amsteel 7/64 it was in my own home with a new rope. The rope broke right as it entered a knot, and was therefore making a sharp right-angle turn. As best I can calculate, the rope was very close to or even above its rated strength.
I've had ceiling hooks in the basement for awhile. However, to test out a bridge hammock, I needed to get the attachment points lower. I'd seen a thread where people were making suggestions about hanging a bridge in a small room, and one guy used floor hooks with heavy-duty chains between the ceiling and floor, and then could put the attachment at any height.
I didn't happen to have any chains, but I did have a spool of Amsteel. So I put a couple of hooks in the wall and tied a couple of loops at eye-level in the near vertical ropes. The bridge hammock then formed an "H" shape along with the two ropes tied wall-to-ceiling. The break occurred on one of the verticals, just above the knot forming the tie-off loop.
In hind sight, I don't recall worrying too much about the wall hooks, although they were anchored well. After I calculated the forces on each piece of the system, I determined that all the hooks had the better part of a ton applied on them. I no longer use the wall hooks.
I've estimated the distances and angles involved, and used rough numbers for calculations. The resulting calculations estimate that my Amsteel broke at a couple hundred pounds higher than the rated strength. I think it more likely that the angles were a little less, the hammock a little lower, etc., and that the rope was very close to 1600 lbs.
By the way, if your wife is in the room above you when you break this stuff, she will be very upset. It literally sounded like a gunshot.
Last edited by Jimbo3b; 03-15-2013 at 09:55..
Reason: Added spreadsheet