Zeppelin bend

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Zeppelin bend
ZeppelinBagi.JPG
NamesZeppelin bend, Rosendahl bend, Rosendahl's knot
Category Bend
Related Zeppelin loop, Hunter's bend, Ashley's bend, Alpine butterfly bend
Releasing Non-jamming
Typical useJoining two ropes of similar size
Instructions

A Zeppelin bend (also known as the Rosendahl Bend) is an end-to-end joining knot formed by two symmetrically interlinked overhand knots. It is stable, secure, and highly resistant to jamming. It is also resistant to the effects of slack shaking and cyclic loading.

Contents

History

The commonly accepted name for this knot stems 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. [1] However, the alleged connection between Charles Rosendahl and the 'Zeppelin bend' has now been refuted. Dr Giles Camplin has conducted extensive research into ground handling of Zeppelin airships and concludes that the Zeppelin bend was not used with mooring lines. Dr Camplin asserts that a rolling hitch (#1735) is a more likely method used by ground handlers to join ropes. Further to that, it is also likely that a 'toggle' was used to unite to mooring lines with fixed eye splice terminations. Dr Camplin's report was published in issue #60 of 'Dirigible' in 2010. Charles Rosendahl (in an interview) was asked about the 'Zeppelin bend' and he denied any knowledge of it.[ citation needed ] Historical records now point to Bob Thrun as the original discoverer in 1966 naming it simply as; 'An easily untied bend' (Published in the 'Potomac Caver' newsletter Vol IX No.7 1966). Bob Thrun was well known in the caving community, and a remarkable innovator.

ABOK#582 to the left, Zeppelin bend to the right, ABOK#582 with folded central section below in the middle ABOK-582 and Zeppelin Bend.jpg
ABOK#582 to the left, Zeppelin bend to the right, ABOK#582 with folded central section below in the middle

Despite being praised by some sources as a nearly ideal rope joining knot, [2] [3] it is not very well known.[ citation needed ] The chapter covering 'bends' (end-to-end joining knots) in original publication of The Ashley Book of Knots does not include this knot. [4] However, at illustration #582, Ashley identifies a 'lanyard knot' which is remarkable because it is a blueprint for tying the Zeppelin bend. Ashley missed the significance of #582. Budworth (1998) identifies #582 as a "blimp knot" in his book; 'The Complete Book of Decorative Knots', p.34. Globe Pequot ISBN   1558217916 because he recognized the geometric similarity with the Zeppelin bend.

With the hindsight of the qualities of the zeppelin bend, a novel use of ABOK#582 is as an alternative to butterfly loop, to isolate a worn section of a long rope where the knot is tied such that the worn section is isolated in the middle of a Z folded central (double-loop-crossing) rope section. The knot will then look like a double slipped zeppelin bend with no ends sticking out.

For an in-depth technical paper on the Zeppelin bend, visit the link at the PACI website: http://www.paci.com.au/knots.php (at #5 in the table).

Tying

Zeppelin bend step by step Zeppelin Bend HowTo.jpg
Zeppelin bend step by step

Fundamentally, the Zeppelin bend is formed from two superposed loops of opposite chirality. This is in contrast to the rigger's bend (AKA Hunter's bend, #1425A) which is formed from two inter-linked loops of the same chirality. Chirality refers to the "handedness" of the loop, which can be either "S" (left) or "Z" (right). The chirality of a loop cannot be changed by flipping or turning it over in the same way, a left shoe cannot be transformed into a right shoe by flipping or turning it over (it is always a left shoe).

The Zeppelin bend is difficult to tie while ropes are under tension (which is further obvious evidence that it wasn't used with mooring lines during ground handling of airships). In fact, with any 'end-to-end joining knot' (ie bend), existing tension in the ropes makes the tying process extremely difficult (if not impossible). The zeppelin is therefore tied with two loose ends (ie no existing tension) 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.

  1. Form a loop in each of the ends of rope (one loop must be "S" and the other must be "Z" chirality)
  2. Superpose (overlay) one loop over the other, orienting each loop so that both working ends face outwards/away from the central overlap.
  3. Feed each working end though the central overlap of the two loops, ensuring that each working end goes in opposite directions.
  4. Dress and set the knot by sequentially pulling on all four rope segments.
  5. To untie, loosen the collars that form around each Standing Part (SPart).
Zeppelin bend forming a loop: the four stages of the method starting with a "clover leaf" or flattened overhand knot; Red line: ends of the overhand knot, Green line: ends of the underhand ZeppelinBagiHalkasi.JPG
Zeppelin bend forming a loop: the four stages of the method starting with a "clover leaf" or flattened overhand knot; Red line: ends of the overhand knot, Green line: ends of the underhand

Another method of remembering this knot is to visualize a "69". To tie the knot with this method, follow the steps below:

  1. Make a "6" with one line (rope) end. It is important that the working end (the free, short end) winds up on top of the standing end for the "6".
  2. Make a "9" with the other line end. Make sure that the working end (the free, short end) winds up on the bottom of the standing end
  3. While keeping the 6 and the 9 intact, place the "6" over the "9", with the holes of each number lining up, making absolutely sure standing ends are on opposite sides of the holes, and both ends are outside, not in between the standing ends.
  4. wrap the "tail" of the "6" first down, around both lines/hole edges, and up through the middle (circle) part of your "69".
  5. wrap the "tail" part of the "9" up, around both lines/hole edges, and down through the middle (circle) part of your "69", it should pass along to the other end in opposite direction.
  6. Pull each standing end while ensuring that the working ends are not pulled back out from the "69" holes to tighten. Pull each working end to tighten even more.

Variants

Corresponding eye (loop) knots

Every end-to-end joining knot, or 'bend', has four corresponding eye knots.

The usual method of creating an eye knot from a bend is by linking a tail with a Standing Part (SPart). Eye knots formed by linking of the two tails or the two SParts are usually of less utility due to the loading profile thus created.

The Zeppelin loop is quite useful and is also jam resistant, being formed by linking a tail to an SPart. An example of a Zeppelin loop is found at this website: https://notableknotindex.webs.com/zeppelinloop.html

Slipped

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.

Tied with bights

If instead of two ends, one forms two bights of the same rope, then three 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 three weak rope sections near each other.

See also

Related Research Articles

Knot Method of fastening or securing linear material

A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a hitch fastens a rope to another object; a bend fastens two ends of a rope to each another; a loop knot is any knot creating a loop, and splice denotes any multi-strand knot, including bends and loops. A knot may also refer, in the strictest sense, to a stopper or knob at the end of a rope to keep that end from slipping through a grommet or eye. Knots have excited interest since ancient times for their practical uses, as well as their topological intricacy, studied in the area of mathematics known as knot theory.

Bowline Simple knot used to form a fixed loop at the end of a rope

The bowline is an ancient and simple knot used to form a fixed loop at the end of a rope. It has the virtues of being both easy to tie and untie; most notably, it is easy to untie after being subjected to a load. The bowline is sometimes referred to as King of the knots because of its importance. Along with the sheet bend and the clove hitch, the bowline is often considered one of the most essential knots.

Millers knot

A miller's knot is a binding knot used to secure the opening of a sack or bag. Historically, large sacks often contained grains; thus the association of these knots with the miller's trade. Several knots are known interchangeably by these three names.

Constrictor knot

The constrictor knot is one of the most effective binding knots. Simple and secure, it is a harsh knot that can be difficult or impossible to untie once tightened. It is made similarly to a clove hitch but with one end passed under the other, forming an overhand knot under a riding turn. The double constrictor knot is an even more robust variation that features two riding turns.

Sheepshank

A shank is a type of knot that is used to shorten a rope or take up slack, such as the sheepshank. The sheepshank knot is not stable. It will fall apart under too much load or too little load.

Clove hitch

The clove hitch is a type of knot. Along with the bowline and the sheet bend, it is often considered one of the most important knots. A clove hitch is two successive half-hitches around an object. It is most effectively used as a crossing knot. It can be used as a binding knot, but is not particularly secure in that role. A clove hitch made around the rope's own standing part is known as either two half-hitches or buntline hitch, depending on whether the turns of the clove hitch progress away from or towards the hitched object.

Although the name clove hitch is given by Falconer in his Dictionary of 1769, the knot is much older, having been tied in ratlines at least as early as the first quarter of the sixteenth century. This is shown in early sculpture and paintings. A round turn is taken with the ratline and then a hitch is added below. The forward end is always the first to be made fast.

The difference between two half hitches and the clove hitch is that the former, after a single turn around a spar, is made fast around its own standing part, while the latter is tied directly around the spar.

Figure-eight knot Type of stopper knot used in sailing and climbing

The figure-eight knot or figure-of-eight knot is a type of stopper knot. It is very important in both sailing and rock climbing as a method of stopping ropes from running out of retaining devices. Like the overhand knot, which will jam under strain, often requiring the rope to be cut, the figure-of-eight will also jam, but is usually more easily undone than the overhand knot.

The figure-eight or figure-of-eight knot is also called the Flemish knot. The name figure-of-eight knot appears in Lever's Sheet Anchor; or, a Key to Rigging. The word "of" is nowadays usually omitted. The knot is the sailor's common single-strand stopper knot and is tied in the ends of tackle falls and running rigging, unless the latter is fitted with monkey's tails. It is used about ship wherever a temporary stopper knot is required. The figure-eight is much easier to untie than the overhand, it does not have the same tendency to jam and so injure the fiber, and is larger, stronger, and equally secure.

Heaving line bend

The heaving line bend is a knot for securely joining two ropes of different diameter or rigidity. It is often used to affix playing strings to the thick silk eyes of an anchorage knot in some stringed instruments. In nautical use, the heaving line bend is used to connect a lighter messenger line to a hawser when mooring ships. It is knot number 1463 in The Ashley Book of Knots, and appeared in the 1916 Swedish knot manual Om Knutar.

Highwaymans hitch Quick-release draw loop knot

The Highwayman’s hitch is a quick-release draw hitch used for temporarily securing a load that will need to be released easily and cleanly. The hitch can be untied with a tug of the working end, even when under tension. The highwayman's hitch can be tied in the middle of a rope, and so the working end does not need to be passed around the anchor when tying or releasing.

Slip knot Type of knot

The slip knot is a stopper knot which is easily undone by pulling the tail. The slip knot is related to the running knot, which will release when the standing end is pulled. Both knots are identical and are composed of a slipped overhand knot, where a bight allows the knot to be released by pulling on an end; the working end for a slip knot, and the standing end for a running knot. The slip knot is used as a starting point for crochet and knitting.

The slip knot is a stopper knot that may be spilled or slipped instantly by pulling on the end to withdraw a loop. There is but one knot entitled to the name; any others having a similar feature are merely " slipped" knots.

Prusik knot

A Prusik is a friction hitch or knot used to attach a loop of cord around a rope, applied in climbing, canyoneering, mountaineering, caving, rope rescue, ziplining, and by arborists. The term Prusik is a name for both the loops of cord and the hitch, and the verb is "to prusik". More casually, the term is used for any friction hitch or device that can grab a rope. Due to the pronunciation, the word is often misspelled Prussik, Prussick, or Prussic.

Halter hitch

The halter hitch is a type of knot used to connect a rope to an object. As the name implies, an animal's lead rope, attached to its halter, may be tied to a post or hitching rail with this knot. The benefit of the halter hitch is that it can be easily released by pulling on one end of the rope, even if it is under tension. Some sources show the knot being finished with the free end running through the slipped loop to prevent it from working loose or being untied by a clever animal, still allowing easy but not instant untying.

Two half-hitches

Two half-hitches is a type of knot, specifically a binding knot or hitch knot. One variety consists of an overhand knot tied around a post, followed by a half-hitch. This knot is less often referred to as a clove hitch over itself, double half-hitch, or full-hitch.

Two half hitches is the commonest of all hitches for mooring in particular and also for general utility. Steel gives the name in 1794. The difference between two half hitches and the clove hitch is that the former, after a single turn around a spar, is made fast around its own standing part, while the latter is tied directly around the spar.

Falconers knot

The falconer's knot is a knot used in falconry to tether a bird of prey to a perch. Some sources show this knot to be identical to the halter hitch, but with a specific method of single-handed tying needed when the other hand is occupied holding the bird.

Bight (knot)

In knot tying, a bight is a curved section or slack part between the two ends of a rope, string, or yarn. A knot that can be tied using only the bight of a rope, without access to the ends, is described as in the bight. The term "bight" is also used in a more specific way when describing Turk's head knots, indicating how many repetitions of braiding are made in the circuit of a given knot.

Shoelace knot

The shoelace knot, or bow knot, is commonly used for tying shoelaces and bow ties.

Double overhand noose

The double overhand noose is a very secure hitch knot. It might be used by cavers and canyoneers to bind a cow tail or a foot loop to a carabiner.[ [File:Noeud double gansé.jpg|thumb|Double overhand noose binding carabiners.]]

Friendship knot loop

Friendship knot loop is a knot to tie a secure and stable loop at the end of a rope.

References

  1. Lee Paine; Bob Paine (Jan–Feb 1980). "The Forgotten Zeppelin Knot". Mother Earth News. Retrieved 2013-08-08.
  2. Brion Toss (1998). The Complete Rigger's Apprentice. Camden: International Marine. pp. 69–70.
  3. "Zeppelin Bend". Notable Knot Index. Retrieved 2010-11-04.
  4. The chapter covering bend knots in The Ashley Book of Knots does not include this knot. See pages 257–274.