Zeppelin bend | |
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Names | Zeppelin bend, Rosendahl bend, Rosendahl's knot |
Category | Bend |
Related | Zeppelin loop, Hunter's bend, Ashley's bend, Alpine butterfly bend |
Releasing | Non-jamming |
Typical use | Joining 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. [1] It is also resistant to the effects of slack shaking and cyclic loading.
The commonly accepted name for this knot stems from its alleged use on airships: a zeppelin being a rigid-bodied type of airship, and Charles Rosendahl being the US Navy officer who allegedly insisted it be used on airships under his command. [2] Dr Camplin asserts that a rolling hitch (#1735) is a more likely method used by ground handlers to join ropes. It is also likely that a 'toggle' was used to connect mooring lines with fixed eye splice terminations. Dr Camplin's report was published in issue #60 of 'Dirigible' in 2010. Historical records now point to Bob Thrun as the first to publish his discovery in 1966 – naming it simply 'An easily untied bend'. [3] Bob Thrun was well known in the caving community, and a remarkable innovator.
Despite being declared by many sources as a nearly ideal rope joining knot, [4] [5] it is not very well known: it is not included in the chapter covering 'bends' (end-to-end joining knots) in the original publication of The Ashley Book of Knots . [6] However, at illustration #582, Ashley identifies a 'lanyard knot' – which is remarkable because it is a blueprint for tying the Zeppelin bend. Budworth identifies #582 as a "blimp knot", because he recognized the geometric similarity with the Zeppelin bend. [7]
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.
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 left (designated "S") or right (designated "Z"). 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' (i.e. bend), existing tension in the ropes makes the tying process extremely difficult (if not impossible). The zeppelin is therefore tied with two loose ends (i.e. 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.
Another method of remembering this knot is to visualize a "69". To tie the knot with this method, follow the steps below:
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://knots.neocities.org/zeppelinloop.html
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.
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.
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.
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.
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.
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.
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.
The Eskimo bowline, Cossack knot, reverse bowline, or 'anti-bowline' is in a class of knots known as 'eye knots' or 'loop knots'. The eye is formed in the end of the rope to permit attachments/connections. It is quite common in Russia and is often used instead of the bowline. In the simple bowline, the collar component forms around the 'standing part'. In contrast, the collar component of an Eskimo bowline forms around the outgoing eye-leg.
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-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.
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.
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.
The adjustable grip hitch is a simple and useful friction hitch which may easily be shifted up and down the rope while slack. It will hold fast when loaded, but slip when shock loaded until tension is relieved enough for it to again hold fast. It serves the same purpose as the taut-line hitch, e.g. tensioning a tent's guy line.
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 used to tie the hitch and the hitch itself, and the verb is "to prusik" or "prusiking". 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.
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 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.
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.
The harness knot is a general purpose bend knot used to join two ropes together. The knot can be tied under tension and will not capsize.
Friendship knot loop is a knot to tie a secure and stable loop at the end of a rope.
The Chinese button knot is essentially a knife lanyard knot where the lanyard loop is shortened to a minimum, i.e. tightened to the knot itself. There emerges therefore only two lines next to each other from the knot: the beginning and the end. The knot has traditionally been used as a button on clothes in Asia, thus the name.
The Chinese Button Knot is worn throughout China on underwear and night clothes. Buttons of this sort are more comfortable to lie on and to rest against compared to common bone and composition buttons, and they cannot be broken even by the laundry.
A Chinese tailor ties the knot without guide, flat on his table. But one may be more quickly and easily tied in hand by a modification of the sailor’s method of tying his knife lanyard knot (#787). The two knots are tied alike, but they are worked differently.
The Lapp knot is a type of bend. It has the same structure as the sheet bend, but the opposite ends are loaded. The slipped Lapp bend is also an exploding knot, which means that when pulling the quick release end it falls completely apart without further entanglement. It is as strong as or even stronger than the sheet bend, though much less common.