It only seems fitting to start a mini series about shedding weight from your rigging, on the day after Thanksgiving. The goals are to minimize rope waste, reduce the number of pieces of gear carried, maximize efficiency and never sacrifice safety. I will be using rope diameters from 9-11mm, manufactured by Sterling Rope, Petzl and Highline Rope.
Sterling Rope generously donated 4 short lengths of static rope for some of these tests.
Upcoming posts:
Figure 8 with bunny ears vs Bowline on a bight
Rigging a 4 pitch horizontal traverse with Butterfly vs Figure 8 knots
Ring hanger and a Bowline on a bight vs twist hanger, carabiner and Figure 8
The Gandalf knot (for Philip)
And more.
Zeppelin bend vs Triple figure 8
Back in March 2020 there was a great discussion about joining two ropes, mid-pitch, of roughly equal diameter together on the Vertical Cavers Facebook page. The common knots used for this are a double fisherman’s knot and a triple figure 8. Greg Moore and Rick Speaect commented about using a Zeppelin bend. Because a double fisherman’s and a flemish bend (figure 8 bend) require a separate knot to create a loop for your cow’s tail to clip into, I am eliminating them from the comparison.
For this test, I used 10mm Work Pro static rope from Sterling, and compared the amount of rope needed to tie the knots and the length of the knots. I did not include the length of the tails. All knots were dressed and tensioned by hand. Lengths were rounded to the nearest 0.25 inch.
The tails should be tied with equal lengths of rope, at least 8 inches each, so that any slippage can be easily seen by tails that are unequal lengths. In both knots the upper rope should be tied with the loop.
5 Triple figure 8s used on average 45.95 inches, which rounds to 46 inches of rope per knot.
1) 45.75 inches
2) 46.5 inches
3) 46.25 inches
4) 46.75 inches
5) 44.5 inches
Triple figure 8
Zeppelin bend
5 Zeppelin bends with eye loop used an average of 32.30 inches, which rounds to 32.25 inches of rope per knot.
1) 30.25 inches
2) 33.25 inches
3) 33.25 inches
4) 32.0 inches
5) 32.75 inches
It is notable that the Zeppelin bend uses 13.75 fewer inches of rope (43% less) than the Triple figure 8, and the ease of adjusting, or untying the knot later on. Now saving over a foot of rope is never a bad thing, it is unlikely that you will need to tie 2 or more ropes together on a single pitch.
The real benefit may be the length of the tied knot/bend, 2 inches for the Zeppelin and 4 inches for the Triple figure 8. When rappelling past the knot with a long frame rack or improperly adjusted cows’ tails that 2 inch difference may make a huge difference on how easy the knot can be passed.
For more information, you can download a paper on the Zeppelin bend from the Professional Association of Climbing Instructors website.
Disclaimer: Nothing on this website should be considered advise or how to techniques, and the information may contain errors. Do not rely on website for training. Be careful!