How to tie the Backup Knot. Climbers often add a “backup knot” to their primary knot for additional security. The purpose of the backup knot is to avoid the primary knot from untying itself. There are numerous back-up knot options, for example a simple overhand knot, but one side of a Double Fisherman's Knot or a "Half Fisherman's" is superior. Although it does use up some rope and is bulky, it is unlikely to work loose, making your primary knot pretty much fail-safe. This version is simply one side of a Double Fisherman's tied with a long tag end (fifteen to eighteen inches) of the primary knot. It is even been proposed that the half-fisherman’s can hold weight by itself should you tie your primary knot incorrectly.
Scroll to see Animated Backup Knot below the illustration and tying instructions.
Backup Knot Tying Instructions
- Wrap the free end twice around the standing rope and the working part of the free end, working back toward the primary knot.
- Feed the free end back through the loops just made.
- Pull free end to tighten backup knot down onto standing line.