Eye splice | |
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Names | Eye splice, sailmaker's eye splice |
ABoK | #17, #2745, #2754 |
Instructions |
The eye splice is a method of creating a permanent loop (an "eye") in the end of a rope by means of rope splicing.
The Flemish eye is a type of circular loop at the end of a thread. There are several techniques of creating the eye with its knot tied back to the line, rope or wire. [3] [4]
There are various splicing techniques, and relate to whether a rope is braided or plaited, whether it has a core and whether the core is made of high-performance fibers. Techniques include:
For conventional stranded ropes, the ends of the rope are tucked (plaited) back into the standing end to form the loop. Three tucks are the minimum for natural fibers, five tucks are necessary for synthetics. [5] Variations of this more traditional eye splice include: [6]
The ends of the rope are first wrapped in tape or heated with a flame to prevent each end from fraying completely. The rope is untwisted for a distance equal to three times the diameter for each "tuck", e.g., for five tucks in half inch rope, undo about 7.5 inches. Wrap the rope at that point to prevent it unwinding further. Form the loop and plait the three ends back against the twist of the rope. Practice is required to keep each end to retain its twist and lie neatly. In stiff old rope or in new rope which has been tightly wound, a marlinspike or fid can facilitate opening up the strands and threading each end.
In some cases, the splice is tapered by trimming the working strands after each tuck. Also, the splice can be whipped to protect and strengthen the splice. A rope thimble can be inserted in the eye to prevent chafing if the eye is to be permanently attached to a fixture (used when attaching a rope to a chain, for example).
An eight-strand rope consists of two left-twisting and two right-twisting pairs. Make sure the left-twisting strands are fed below left-twisting strands, and right-twisting strands below the right-twisting ones. Work systematically with different tape colours to keep from getting lost in the mess of strands. An eight-strand square plaited rope can be used as mooring line or anchor rode. [7]
This technique is mostly used for Dyneema ropes. [8] The principle of a Dyneema eye is a core-to-core splice, in which a length of at least 60 times the diameter of the rope is taken back into itself. DSM advises using 60 times the diameter for coated Dyneema, and 100 times the diameter for uncoated Dyneema. For 6mm coated rope, this would mean 36 cm. Under tension the rope will pull into itself tightly, which produces a strong eye. One can pull out the eye when the rope is not under tension, unless one makes a lock-splice (also called brummel splice).
In ropes with a polyester (or nylon) core, both the core and the cover are needed for strength. [8]
Splicing a rope with a laid core is usually more complicated than double braided polyester ropes. One needs more force to take the rope back into itself because there is often less room between the core and the cover. [7]
A rope with parallel fibers in the core often has a tight inner cover to keep the fibers together. This splice is similar to the one for double braided polyester ropes; the main difference is that one cannot take the cover back in to the core because the fibers go through the core. [9]
Instructions are published in [9] Splicing Modern Ropes (a practical handbook)
For ropes with a core of high-performance fibers (such as aramid fibers or Dyneema or Vectran) only the core determines the strength. The cover can be used optionally in the eye splice, for example, to add UV protection (for aramid fibers, such as Kevlar). Dyneema is very UV resistant and the cover is not needed. For these ropes, one could make an eye splice in the single braided core and leave the cover unused. There are ropes with an extra double layer cover; this is basically the same splice as for double braided except that the inner cover first needs to be removed over the length of the splice.
Depending on the type of splice and rope, there is a variety of tools available such as hollow fids, pulling needles and traditional splicing fids. Make sure to also have a marker, splicing tape, measuring tape and a knife or scissors at hand. Often a hammer and winch are used as well for tougher splices.
This section needs additional citations for verification .(March 2020) |
An inch of good splice[ vague ] will hold 1 ton. The eye splice has several advantages. The most notable is the permanence of the loop. An equally important advantage is the lack of stress it puts on the rope. Splices average 25-40% of rope strength decay, which is low compared to even the strongest knots. [10] Literature and reference sources typically attribute only a 5% strength decay for a properly tied splice. Technically, a perfectly tied splice retains 100% of the original strength of the rope but in practice this is rarely the case. Destructive testing of rope in manufacturing facilities makes use of a professional and spliced eyes for connecting the rope to the testing apparatus.
The bowline is a quick, practical method of forming a loop in the end of a piece of rope. However, the bowline has an awkward tendency to shake undone when not loaded. The bowline also reduces the strength of the rope at the knot to ~45% of the original unknotted strength. [ citation needed ]
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.
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 trucker's hitch is a compound knot commonly used for securing loads on trucks or trailers. The general arrangement, using loops and turns in the rope itself to form a crude block and tackle, has long been used to tension lines and is known by multiple names. Knot author Geoffrey Budworth claims the knot can be traced back to the days when carters and hawkers used horse-drawn conveyances to move their wares from place to place.
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.
A whipping knot or whipping is a binding of marline twine or whipcord around the end of a rope to prevent its natural tendency to fray.
The timber hitch is a knot used to attach a single length of rope to a cylindrical object. Secure while tension is maintained, it is easily untied even after heavy loading.
A climbing harness is a device which allows a climber access to the safety of a rope. It is used in rock and ice climbing, abseiling, and lowering; this is in contrast to other activities requiring ropes for access or safety such as industrial rope work, construction, and rescue and recovery, which use safety harnesses instead.
A braid is a complex structure or pattern formed by interlacing three or more strands of flexible material such as textile yarns, wire, or hair.
A shackle, also known as a gyve, is a U-shaped piece of metal secured with a clevis pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. The term also applies to handcuffs and other similarly conceived restraint devices that function in a similar manner. Shackles are the primary connecting link in all manner of rigging systems, from boats and ships to industrial crane rigging, as they allow different rigging subsets to be connected or disconnected quickly. A shackle is also the similarly shaped piece of metal used with a locking mechanism in padlocks. A carabiner is a type of shackle used in mountaineering.
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly constructed cord, string, and twine.
Rock-climbing equipment requires a range of specialized sports equipment, for training, for aid climbing, and for free climbing. Developments in rock-climbing equipment played an important role in the history of rock climbing, enabling climbers to ascend more difficult climbing routes safely, and materially improving the strength, conditioning, and ability of climbers.
Rope splicing in ropework is the forming of a semi-permanent joint between two ropes or two parts of the same rope by partly untwisting and then interweaving their strands. Splices can be used to form a stopper at the end of a line, to form a loop or an eye in a rope, or for joining two ropes together. Splices are preferred to knotted rope, since while a knot typically reduces the strength by 20–40%, a splice is capable of attaining a rope's full strength. However, splicing usually results in a thickening of the line and, if subsequently removed, leaves a distortion of the rope. Most types of splices are used on 3-strand rope, but some can be done on 12-strand or greater single-braided rope, as well as most double braids.
While a spliced 3-strand rope's strands are interwoven to create the splice, a braided rope's splice is constructed by simply pulling the rope into its jacket.
Kernmantle rope is rope constructed with its interior core protected by a woven exterior sheath designed to optimize strength, durability, and flexibility. The core fibers provide the tensile strength of the rope, while the sheath protects the core from abrasion during use. This is the only construction of rope that is considered to be life safety rope by most fire and rescue services.
Parachute cord is a lightweight nylon kernmantle rope originally used in the suspension lines of parachutes. This cord is now used as a general purpose utility cord. This versatile cord was used by astronauts during the 82nd Space Shuttle mission to repair the Hubble Space Telescope.
Wire rope is several strands of metal wire twisted into a helix forming a composite rope, in a pattern known as laid rope. Larger diameter wire rope consists of multiple strands of such laid rope in a pattern known as cable laid.
A fid is a conical tool traditionally made of wood or bone. It is used to work with rope and canvas in marlinespike seamanship. A fid differs from a marlinspike in material and purposes. A marlinspike is used in working with wire rope, natural and synthetic lines, may be used to open shackles, and is made of metal. A fid is used to hold open knots and holes in canvas, and to separate the "lays" of synthetic or natural rope for splicing. A variation of the fid, the gripfid, is used for ply-split braiding. The gripfid has a jamming cleat to pull a cord back through the cord split by the fid's point.
A bowstring joins the two ends of the bow stave and launches the arrow. Desirable properties include light weight, strength, resistance to abrasion, and resistance to water. Mass has most effect at the center of the string; one gram (0.035 oz) of extra mass in the middle of the string slows the arrow about as much as 3.5 grams (0.12 oz) at the ends.
A top is a hand tool with an iron loop and hook used in the creation and splicing of rope. A Top is used to simultaneously hold a piece of rope while providing a hole to separate the "lays" of synthetic or natural rope for splicing. A variation of a Top, the gripfid, is used for ply-split braiding. The gripfid has a jamming cleat to pull a cord back through the cord split by the fid's point. A variation of a Top can also be used as a rope wrench, rope separator or rope tool can be used in the manufacture of laid rope. The top is used to prevent the strands of a rope twisting together prematurely, which would lead to the rope being loose, allowing it to untwist. The amount of pressure applied to the top determines the stiffness of the final product; more pressure forces the strands together more tightly, making a rope that is harder to bend.