|Names||Zeppelin bend, Rosendahl bend, Rosendahl's knot|
|Related||Zeppelin loop, Hunter's bend, Ashley's bend, Alpine butterfly bend|
|Typical use||Joining two ropes of similar size|
A Zeppelin bend (also Rosendahl bend) is a general-purpose bend knot. It is a secure, easily tied, and jam-resistant way to connect two ropes. Though its simplicity and security may be matched by other bends, it is unique in the ease with which it is untied, even after heavy loading, by pulling the opposing bridges away from each other.
Both names for this knot stem from its alleged use to moor airships: a Zeppelin being a rigid-bodied type of airship, and Charles Rosendahl being the US Navy officer who allegedly insisted it be used to moor airships under his command.
The zeppelin bend is a relatively new bend. Despite being praised by some sources as a nearly ideal bend knot, it is not very well known. The original publication of The Ashley Book of Knots does not include this knot; the Hunter's bend (a topologically similar but jamming variant of the zeppelin bend) was added in 1979. Budworth (1998) names a similar-looking decorative knot as the "blimp knot".
Zeppelin bend is difficult to tie while ropes are under tension, difficult also to tighten either main part, during or after tying, by pulling through the knot; Harness bend is better for that purpose. The zeppelin is therefore tied with two loose ends ending with a simple knot on each, but woven to each other in a pattern specific to Zeppelin. Butterfly bend, Hunter's bend, and Ashley's bend also weave one simple knot on either end but use their own different patterns.
- Form a loop in each of the ends of rope.
- Overlay one loop on the other, such that the working end of each rope faces "outwards" or away from the other hitch.
- Pull either loose end once around the loop in the other rope, and then through the "tunnel" created by the two hitches.
- Repeat with the other loose end.
- Pull on all four rope parts to tighten the knot.
- To untie, pull simultaneously on the two turns that go round the standing parts.
Another method of remembering this knot is to visualize a "69". To tie the knot, follow the steps below:
- Make a "6" with the line (rope) in your left hand. It is important that the working end (the free, short end) winds up on top of the standing end for the "6".
- Make a "9" with the line in your right hand. Make sure that the standing part crosses over the working end of the "9".
- While keeping both "numbers" intact, place the "6" over the "9", with the circle parts of each number lining up.
- Pass the "tail" of the "6" down, over itself, and up through the middle (circle) part of your "69".
- Pass the "tail" part of the "9" up over itself and down through the middle (circle) part of your "69".
- Pull each standing end while ensuring that the working ends are not pulled from the "69" holes.
Having on both ends, an elbow of the end rather than the end itself, cross the knot center, gives a single or double slipped version. It is still easier to untie by pulling the opposing bridges away from each other rather than by pulling the slipped end(s). The slipped Zeppelin bend can also be locked by pushing ends respectively through the eye of its own slip on the opposite side.
On the bight
If instead of two ends, one ties two bights of the same rope, then 3 reliable loops are created; a loop at each of the two bights, and a third formed by the rope section connecting the two bights. These versions also have the same advantage with less curvature nearest the main ropes, thus having a higher break strength and being as easy to untie. This is also a way to shorten the rope, and/or to isolate up to 3 weak rope sections near each other.
- Lee Paine; Bob Paine (Jan–Feb 1980). "The Forgotten Zeppelin Knot". Mother Earth News. Retrieved 2013-08-08.
- Brion Toss (1998). The Complete Rigger's Apprentice. Camden: International Marine. pp. 69–70.
- "Zeppelin Bend". Notable Knot Index. Retrieved 2010-11-04.
- The chapter covering bend knots in The Ashley Book of Knots does not include this knot. See pages 257–274.
- Budworth, Geoffrey (1998). The Complete Book of Decorative Knots, p.34. Globe Pequot. ISBN 1558217916.