I have been playing with bowline variants, and I'm interested in the various methods of "locking" or otherwise adding to the security of the standard bowline. After reading Mark Gommers's paper (
http://www.paci.com.au/downloads_public/knots/Bowlines_Analysis.pdf), I'd like to propose this addition to the double bowline. (Of course, please let me know if this has been suggested before.) In my head while I've been playing with it I've been calling it a Backflip Double Bowline because of the way the working end wraps around the back of the two turns of the nipping loop to pass down through them again.
It's somewhat similar to the knot labeled in the above paper "Lee's locked bowline," and a comparison to it illustrates why I think this knot has a security advantage. With Lee's locked bowline, the Yosemite finish is applied, and then the working end is tucked back down through both the nipping loop and the Yosemite turn around the leg of the eye. In a manner of speaking, this essentially adds two locks (Yosemite finish and then additional tuck) to a standard bowline.
The knot shown below starts with a more secure form of the bowline to begin with. Then the working end is further locked by being passed through the double nipping loop a second time. So this knot makes use of the added security of the double bowline twice, once in the "base" knot and then again in the lock applied.
The resulting form of the knot looks almost identical to Lee's locked bowline and produces a neat and compact knot that seems - in my limited tinkering - to be stable, resistant to ring loading, and easy to untie. I need to do more testing with heavier loads and in different ropes. The knot is shown below tied in 550 paracord.
I'd be grateful for your comments.