Sailors and other rope users are familiar with the process of sweating or swigging up a line: pulling sharply sideways on the fall of a purchase, above the belay point to gain a bit of slack, then quickly transitioning to a downward resolution, so that slack can be taken up at the belay point. The combination of leverage and impact-loading allows you to get more tension than you could by simply pulling down on the line. But the question is: how much more?
In the video below our rigger Julia Briggs is sweating a line in our shop. The line has been set to a starting tension of 200lbs.
Julia weighs 140 lbs.
The line is attached to a load cell that has been set up to read the maximum tension achieved.
So here is the puzzle: how many additional pounds of tension did Julia impose?
Note that Julia makes no effort to take the slack towards the floor; we just wanted to see how much extra tension could be gained. If you have some idea about the result, send it to email@example.com, or write it in the comments section below. Anyone whose guess is within 150 pounds of the actual answer will win a free copy of my new book, Falling, a series of stories about working at heights. You get your choice of an ebook or audiobook version.
Puzzle entry deadline is noon Pacific time, January 5th, 2019, and the winners will be announced on January 7th. Good luck!