What are flat knots?
These are the asymmetrical type knots you use for tying two ropes together for abseiling/rappeling. You know, the ones that roll nicely over edges with out snagging due to their asymmetrical profile, rotating them away from the rock.
There are several out there but the main ones are;
1. overhand-flat knot (the so called - EDK)
2. figure eight-flat knot (instant-death knot!)
3. figure nine-flat knot (much safer, than 2.)
I have noticed an alarming amount of ropes being joined with the "figure eight-flat knot" in KOREA and often with only 6-10 inches of tail and no backup. These knots have failed and killed people in the past. By failed I mean the knot has "Capsized/rolled" right off the end of the rope!
This got me thinking (doesn't happen too often
). I personally have been using the "tried and tested" "overhand-flat knot" (the so called - EDK) with a backup behind it. I recently found out this too can tumble over itself if not tightened well enough and not backed up. But it requires a lot more energy than the figure eight-flat knot to do so.
I also learned about a new addition to the "flat-knot" team, number 4 on the list. Edelrid did a test on it and it held until the rope broke! Great! Im changing, perhaps you might like to too! The figure nine-flat knot also held up well in a seperate Black Diamond test as it has a built in back up knot).
Overhand-flat knot (the so called - EDK)