THE QUESTION
what knot is this? any idea?
THE ANSWER
Bowline. In this form it's sometimes called a 'double bowline'.
In the old days this knot was used to tie the rope around your waist- no harness. If the leader fell, and the rope didn't break, the result was not pretty- broken ribs were common. When harnesses first came around the bowline, and later the double bowline, was the standard tie in knot. Some people still use it to tie in, it's supposed to be easier to untie after being loaded than a figure eight, but it has sharper bends in it which means it's a slight bit weaker than the figure eight. Any bend in a rope lowers its breaking strength, and the sharper the bend the more the rope is weakened. The figure eight has the least sharp bends of any known knot, making it the 'strongest'. It is also easy to tie and easy to glance at it and verify it is tied correctly- which are the main reasons it is preferred by most climbers today.
Note: This post was ghost written by me for "could have been my first guest blogger but refused" Neal Harder in response to http://twitter.com/sudarkoff/status/5836400206. aka I just copied his email response into this form since he's "allergic" to blogging.
