Reef knot – Wikipedia

This article is about a r-2 ravel. For the numerical adaptation, see Square knot ( mathematics ) character of knot

Reef knot
Square knot.svg
Names Reef knot, Square knot, Hercules knot, Double knot, brother hood knot
Category Binding
Origin Ancient
Related Thief knot, Granny knot, Grief knot, Surgeon’s knot, Shoelace knot
Releasing Jamming
Typical use Joining two ends of a single line to bind around an object.
Caveat Not secure as a bend unless secured by additional knots(ex: overhand). Spills easily if one of the free ends is pulled outward. Does not hold well if the two lines are not the same thickness.
ABoK #74, #75, #460, #1204, #1402, #2096, #2573, #2574, #2577, #2580
Instructions [1]

The reef knot, or square knot, is an ancient and childlike binding knot used to secure a rope or line around an object. It is sometimes besides referred to as a Hercules knot. The ravel is formed by tying a left-handed overhand knot between two ends, alternatively of around one end, and then a dextrorotary overhand nautical mile via the lapp procedure, or vice versa. A common mnemonic for this operation is “ right over left ; left over right ”, which is frequently appended with the rhyming suffix “ … makes a knot both tidy and close ”. Two back-to-back overhands tied as described above of the lapp handedness will make a grandma knot. The working ends of the reef knot must emerge both at the top or both at the bottom, otherwise a thief nautical mile results .

The reef knot or straight knot consists of two half knots, one leave and one right, one being tied on top of the early, and either being tied inaugural … The reef knot is unique in that it may be tied and tightened with both ends. It is universally used for parcels, rolls and bundles. At sea it is always employed in reefing and furling sails and stopping clothes for drying. But under no circumstances should it ever be tied as a bend, for if tied with two ends of inadequate size, or if one end is stiffer or smoother than the other, the ravel is about bound to spill. Except for its true purpose of binding it is a knot to be shunned.

The Ashley Book of Knots[1]

The witwatersrand knot is not recommended for tying two ropes together, because of the electric potential instability of the knot when not stabilized ; something that has resulted in many deaths ( see Misuse as a flex ) .

Naming [edit ]

The reef knot is at least 4,000 years old. The name “ reef knot ” dates from at least 1794 [ 2 ] and originates from its common use to reef sails, [ 3 ] [ 4 ] that is to tie partially of the sail down to decrease its effective surface area in strong winds. To release the knot a bluejacket could collapse it with a draw of one hand ; the sail ‘s weight would make the collapse slub come apart. It is specifically this behavior which makes the knot dangerous for connecting two ropes together. [ 5 ] The name “ square slub ” is found in Dana ‘s 1841 nautical collection A Seaman’s Friend, which besides gives “ reef knot ” as an alternative name. [ 6 ] [ 7 ] The name square knot is frequently used for the unslipped version of reef knot. Reef knot itself then is silent as the single slip interpretation, while the name shoelace knot is to indicate double slip adaptation. Sometimes the name bowtie besides may be used to indicate a double slip version, but tying a bow tie is normally performed on flat material, and involves a case nautical mile of one end holding a bight of the other end i.e. not in truth a double slipped witwatersrand knot. The name “ Square slub ” is besides used for completely different other knots such as the mathematical concept of square knot, or friendship knot ; this stopping point one earns the name by being flat and drawing a square on one confront ( and a traverse on the other expression ) .

Uses [edit ]

The reef knot is used to tie the two ends of a unmarried rope together such that they will secure something, for case a package of objects, that is improbable to move much. In accession to being used by sailors for reefing and furling sails, it is besides one of the key knots of macrame textiles. [ 8 ] The knot lies flat when made with fabric and has been used for tying bandages for millennium. As a tie ravel it was known to the ancient Greeks as the Hercules knot ( Herakleotikon hamma ) and is still used extensively in medicine. [ 9 ] In his Natural History, Pliny relates the impression that wounds heal more promptly when oblige with a Hercules knot. [ 10 ] It has besides been used since ancient times to tie belts and sashes. A modern use in this manner includes tying the obeah ( or swath ) of a martial arts keikogi. With both ends tucked ( slipped ) it becomes a dear direction to tie shoelaces, whilst the non-slipped adaptation is utilitarian for shoelaces that are excessively short. It is appropriate for tying plastic drivel or pan bags, as the slub forms a wield when tied in two wrench edges of the bag. The reef knot figures prominently in Scouting cosmopolitan. It is included in the international membership badge [ 11 ] and many scout awards. [ 12 ] In the Boy Scouts of America demonstrating the proper bind of the squarely knot is a prerequisite for all boys joining the broadcast. [ 13 ] In Pioneering ( Scouting ), it is normally used as a binding knot to finish off specialize lashing ( ropework ) and whipping knots. [ 14 ] however, it is an insecure ravel, mentally ill when jiggled, and is not desirable for supporting weight.

A surgeon ‘s variation, used where a third gear hand is unavailable, is made with two or three twists of the ropes on bottom, and sometimes on top, rather of merely one .

Misuse as a bend [edit ]

The reef knot can capsize ( spill ) when one of the detached ends is pull outward. The reef knot ‘s casualness, comfort of bind, and visually appealing isotropy conceal its failing. The International Guild of Knot Tyers warns that this nautical mile should never be used to bend two ropes together. [ 15 ] however, advanced education teaches that it is fine for uncritical applications, [ 16 ] particularly if stabilized. A proper flex knot, for example a sheet flex or double fisherman ‘s ravel, should be used rather. Knotting authority Clifford Ashley claimed that misused reef knots have caused more deaths and injuries than all other knots combined. [ 17 ] Further, it is easily confused with the granny knot ravel, which is a very inadequate ravel.

physical psychoanalysis [edit ]

An approximate forcible analysis [ 18 ] predicts that a witwatersrand knot will hold if 2 μ east μ π ≥ 1 { \displaystyle 2\mu e^ { \mu \pi } \geq 1 } 2\mu e^{{\mu \pi }}\geq 1, where μ is the relevant coefficient of friction. This inequality holds if μ ≳ 0.24 { \displaystyle \mu \gtrsim 0.24 } \mu \gtrsim 0.24. Experiments show that the critical value of μ is actually reasonably lower. [ 19 ]

refer knots [edit ]

See besides [edit ]

Notes and references [edit ]

reference :
Category : Synthetic

Trả lời

Email của bạn sẽ không được hiển thị công khai.