I have a wooden beam in the attic of our house. The beam is about 13cm wide and 21cm high, making it rectangular. I want to use it as an anchor point. To test it, I took my rope and wrapped it around the beam many times. Then I tied two figure-eight knots with two ends of the rope, making loops 30cm above the ground. I stood with my feet in the two loops. Then I rocked back and forth for 2 minutes and then stood on the loops for a total of 40 minutes without wobbling. The beam didn't make any dangerous noises and remained completely undamaged; it looked exactly the same as before. Can I be sure that it will hold if I hang myself completely? I'm not going to jump off the ledder because that would increase my weight fivefold for a brief moment. Instead, I want to hold on to the ladder with my hands, then slowly take my feet out of the ladder step, slowly lower myself into the air and then push the ladder away with my hands. The beam already had a few cracks, but those are normal for a beam like this; they were there before, and they didn't get any bigger or deeper after the test. Beams naturally develop cracks over time.
