wire rope eye splice strength free sample

A light thimble can distort under high load. Cheap wire thimbles often have sharp edges, and even well-polished examples can open the weave or chafe at strands, or seriously damage a splice if they shift.

At the heart of the problem is stretch. Nylon double braid rope stretches about 12 percent for every 20 percent of breaking strength; 3-strand rope stretches about 15 percent and climbing ropes stretch about 18 percent. Because each leg of the eye carries only half of the load, the stretch at 20 percent of breaking strength should be only 6 percent, but we must add to that some construction stretch, since it takes time for a splice to settle in. As a result of all the stretch, even factory-installed thimbles become loose at high load.

Even when a thimble is very well-fitted and tightly seized-as good and any we have seen-and stretched to the normal working load (10 percent breaking strength), it becomes quite loose. Any side load or binding could allow the thimble to shift its position. We were sent images of a bridle on a Jordan Series Drogue (a drag device used to slow the boat in a storm), and the bridle was severely chafed by a thimble that shifted. Had it failed, the consequences would have been serious. A closed thimble or a webbing sleeve is a safer choices for this application. We’ve seen similar near failures resulting from open-style thimbles in mooring applications as well.

Wear. A mooring line around a rusty shackle is a perfect case for a thimble. Abrasion is aggressive, and a nice thick layer of steel offers the best protection. But what about eyes attached to polished stainless shackles? Unless they are under extreme load and simultaneously sawing back-and-forth across the shackle pin, ring, or other load-bearing attachment point, there will be virtually no apparent wear.

Any rope is weakened when loaded around a small radius. The fibers on the outside carry more load than those on the inside, which may actually be slack, doing no work at all. This effect can be mitigated by changing the ratio of the rope diameter (D) to the diameter of the shackle pin (d) or other attachment point.

For determining block size, D/d ratios of at least 8 are recommended to cope with the loads and the greater potential for chafe. But depending on the application, the loads, and type of line used, the D/d ratio for an eye-splice can be as little as 1:1 without risking failure. The following discussion of D/d ratios applies only to spliced eyes in a splice, in which each leg carries only 50 percent of the load.

Wire rope. Wire rope is the extreme case, requiring a 20:1 D/d ratio. Wire does not stretch, and is subject to fatigue if repeatedly bent, and thus a thimble is required to increase the radius. Since wire rope does not stretch much, and because the cable is also steel, the thimble should stay put and would do little harm if an edge did chafe the cable.

Nylon. Fibers that stretch (nylon) do not suffer extreme strength reduction around a tight radius, because the fibers naturally share the load better. When the ratio of the rope diameter (D) to diameter of the pin (d) or shackle is 1:1, nylon is the strongest of all common rope constructions.

When the D:d ratio = 1 with these ropes, the strength of the eye is undiminished. It is true that each leg of the eye is weakened 50 percent, but because each leg only carries 50 percent of the load, the strength of the eye is undiminished, and the splice is usually the first to fail.

In the case of nylon, some increase in diameter may be desirable for lines that are routinely loaded over their working load limit (9 percent of breaking strength). Factory-added spinning lubricants help resist chafe but don’t last. This protection be partially restored in used ropes by treating them with certain water repellent coatings (see Winter Sailing Tips for Die-Hards, Practical Sailor, December 2016).

High molecular polyethylene (HMPE): Slippery HMPE fibers (such as Dyneema) share the load better, since they can easily slip over each other. Like nylon, when the D:d ratio = 1, the strength of the eye is undiminished. Because the line diameter and the pin diameter are generally about equal strength in applications that use Dyneema, no thimble is required. Heat-set Dyneema, used for standing rigging, is a special case, and should have a thimble or ring.

Polyester: What about polyester, so common in running rigging? In most cases it is oversized for stretch and hand, and thus will be working so far below its working load limit (20 percent of breaking strength) it is irrelevant.

The bottom line is that during our entire break-testing program of Dyneema, nylon, and polyester eye splices, we never saw a failure over the pin (see Sewn Splices Follow Up, PS June 2016). We saw failures within the splice, at the end of the splice, in the throat, and even in the center of the rope, but never at the pin.

Traditional and often cheap, lighter-duty open thimbles distort under load and have sharp edges. Even strong, well-polished versions can shift and damage rope. Occasionally the splices are tightly lashed in place, but this is like treating the symptoms rather than the cause.

Either welded or cast in an elliptical shape, these present no sharp edges that can damage a rope or sail. However, they do increase the throat angle (the angle formed by the two legs of the spliced eye) slightly and can fall out if poorly fitted or highly strained.

Traditionally used on large mooring hawsers because of the challenges in fitting other thimble types to large stiff lines, these have become popular with Dyneema winch cables. Their ability to maintain strength even after being distorted is a great asset.

In many cases, this may be all the protection you need. The thick nylon tubular webbing pads over sharp corners, increases the D/d ratio slightly, and easily manages any abrasion that can occur between a polished pin and the rope.

It also has advantages that no other thimble design can match: they cannot slip out of position, damage the rope, or scratch the deck. They are lighter, cost practically nothing, install in seconds, and are suitable for knotted loops as well. Perhaps the only downsides are that they are still unfamiliar to many sailors, and the appearance is decidedly non-traditional.

Made from very densely woven nylon, this well-proven chafe gear lasts at least 10 times longer than a typical polyester rope cover. For additional wear, coat with Maxijacket.

Often covers are available, either from high modulus line covers that have been stripped by racers, or salvaged sections of lines that have seen little wear (the portion of a halyard that lived inside the mast is often very good). A larger size can be slid over the eye. A cover is particularly useful for knotted lines, where it can also reinforce the knot.

This thin but incredibly durable covering proved virtually wear-proof in prior testing (UV, Chafe Protection, March 2105 Practical Sailor ). The only down side is the ends are difficult to melt, and tucking it in is impractical in a splice. Thus, a neat job requires advanced skills.

We’re not fond of wire rope thimbles for tough jobs. Although they have a long, generally successful history, we’ve seen too many cases where the thimble itself did serious damage. A sailmakers thimble is one answer. There are no sharp edges and they do not distort under high load.

For very high load, larger lines, and even knotted eyes, captive thimbles offer a more expensive but dependable solution. That would be our choice for a mooring pendant, combination rope-chain rode (splicing direct to the chain is even better), Jordan Series Drogue, or sea anchor. But for most running rigging jobs, either no thimble or a webbing chafe sleeve is the best answer.

In stricter senses, the term wire rope refers to a diameter larger than 9.5mm (3⁄8in), with smaller gauges designated cable or cords.wrought iron wires were used, but today steel is the main material used for wire ropes.

Historically, wire rope evolved from wrought iron chains, which had a record of mechanical failure. While flaws in chain links or solid steel bars can lead to catastrophic failure, flaws in the wires making up a steel cable are less critical as the other wires easily take up the load. While friction between the individual wires and strands causes wear over the life of the rope, it also helps to compensate for minor failures in the short run.

Wire ropes were developed starting with mining hoist applications in the 1830s. Wire ropes are used dynamically for lifting and hoisting in cranes and elevators, and for transmission of mechanical power. Wire rope is also used to transmit force in mechanisms, such as a Bowden cable or the control surfaces of an airplane connected to levers and pedals in the cockpit. Only aircraft cables have WSC (wire strand core). Also, aircraft cables are available in smaller diameters than wire rope. For example, aircraft cables are available in 1.2mm (3⁄64in) diameter while most wire ropes begin at a 6.4mm (1⁄4in) diameter.suspension bridges or as guy wires to support towers. An aerial tramway relies on wire rope to support and move cargo overhead.

Want to do your own rigging and splicing of ropes? We have made more than 30 rope splicing instruction videos. For example, how to make an eye-splice in modern ropes? Or how to make soft shackles from ropes with Dyneema® fibers? Watch our video"s! The reference numbers correspond to the chapters of "Handbook Splicing Modern Ropes".

Want to start with splicing? Check out our wide range of splicing tools. And do you already have our Rope Splicing App on your phone? All splicing instructions in your pocket and easy to use off-line!

If your rope does not hold in jammers or clutches, splice an extra cover or add an extra core. Chafing covers from Technora or Dyneema®are great to extend the life of your ropes.

Splicing modern braided ropes of super fibres is quite fun and easy to learn. Premiumropes has uploaded various splicing tutorials, such as eye-splices, soft shackles, taper sheets or make a continuous furler line. Make sure you have enough space to work and an anchoring point for your rope. If you are on board, you can use a winch in case you need extra force. Choose a fid that matches the diameter of the rope, or even one that is slightly thinner. Never use pliers to pull out a fid from the rope - you will damage it! Do you know what the construction of your rope is? Check our table what splicing technique to choose for which type of rope. The core material largely determines the type of splice, whether it is core dependend or if you need to use the cover in the eye-splice too.

A splice is a way of terminating a rope or joining two ends of rope together without using a knot. Apart from being bulky and unsightly, even a correctly tied knot can cause significant loss of strength to a rope. At Marlow our splicing team have over 150 years of combined splicing knowledge and experience and we offer a splicing service to our trade and commercial customers for bespoke rope assemblies, slings and strops. For sailors and boat owners, we always recommend using your local rigging professional to splice and install your ropes. Find your local Marlow Rigging professional here.

For those wishing to splice their own ropes, we have produced a comprehensive splicing guide and range of splicing tutorials (scroll down to view) detailing a range of splicing methods. For hands-on splicing demonstrations, visit the Marlow stand at any of our shows and exhibitions throughout the year, or sign up to attend a Marlow Rope-Show held across the UK at sailing clubs once per month.

The Mazzella 6 x 37 IWRC (independent wire rope core) single-leg wire rope sling has eye-and-eye endings and a mechanical splice for lifting loads with vertical, choker, or basket configurations in general industry applications. The 6 x 37 IWRC construction contains six strands of wire rope with approximately 37 wires per strand wrapped around a separate 7 X 7 wire rope, which has seven strands with seven wires per strand, in the center of the sling. This construction provides more flexibility than a 6 x 7 or 6 x 19 wire rope sling. The wire rope construction has more abrasion and heat resistance than a web sling. This eye-and-eye sling has an eye, or loop, on both ends, and can be used with vertical, choker, and basket lifting configurations. The eyes are secured with a mechanical (also called Flemish) splice that is stronger than a hand splice. This sling has a minimum D/d ratio of 25 and meets American Society of Mechanical Engineers (ASME) specification B30.9 and Occupational Safety and Health Administration (OSHA) specification 1910.184.

Slings are used to lift heavy objects for industrial applications. Types of slings include web slings, wire rope slings, chain slings, and mesh slings. The appropriate type of sling for an application depends on the strength-to-weight ratio, flexibility and resistance to bending, resistance to abrasion and cutting, resistance to crushing, resistance to stretching, and resistance to high temperatures and other environmental stressors. Slings have one, two, three, or four legs; or a continuous loop of webbing or wire rope. Legs are support branches that extend from a single point at the top of the sling to the item being lifted so the weight of the load is distributed evenly among the branches. Slings have eyes (loops) or alloy steel fittings on the ends.

A vertical lifting configuration connects a crane hook directly to a load with a single, vertical sling, usually by means of a hook. In a choker configuration, the sling wraps entirely around the load, and one loop passes through the other to form a slip noose, or choker. In a basket configuration, the sling passes under the load and both ends of the sling connect to the crane hook. Load capacity is the maximum weight to be lifted in a vertical configuration. The capacity in a choker configuration is approximately equal to the vertical capacity times 0.8. The capacity in a basket configuration, with sling ends at a 90-degree angle, is approximately equal to twice the vertical capacity. Load capacity in a basket configuration decreases if the angle of the sling is less than 90 degrees. For example, a sling with a capacity of 2,000 lb. in a vertical configuration will have an approximate capacity of (2,000)(0.8)=1,600 lb. in a choker configuration and an approximate capacity of (2,000)(2)=4,000 lb. in a basket configuration, if the sling ends are at a 90-degree angle to the load. A wire rope sling"s capacity in a basket configuration applies only when the configuration meets the sling"s minimum D/d ratio, which is the ratio of the diameter of the rope"s curve around the load (D) to the diameter of the sling (d). If the minimum D/d ratio is not met, the capacity of the sling is decreased.

Splicing Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NOTE* ! * ! * ! * ! BACK IN STOCK ! * ! * ! * ! Basic Braided Splices - Book 5 of the Working Rope Field Guides by Brion Toss

Brion"s new most favorite tool - HM Shears for cutting all High Modulus Rope - cuts like butter. If you can get these shears around the rope - you can cut it. check them out - very bottom of this page.

Braided and High Modulus (aka Parallel-Core) Rope splicing can be a daunting, frustration task, if you are using conventional tools and instructions. That"s why the Splicing Wand was invented, a tool that makes quick, easy work of tucking.

The Splicing Wand is basically a long tube containing a hidden snare. You slide the tool into the rope, grab the end you want to tuck, and slide the tool out. There"s a specially-shaped tip on the tube, to keep you from snagging yarns along the way, an ingenious mechanism in the handle, to hold the tube in place while you work. You can clamp the tool in a vise if you want, leaving both hands free to deal with the rope, there"s no taping or un-taping, no fid lengths to decipher,and very little physical effort needed to tuck.

The Splicing Wand comes in six sizes - the inches noted are for rope diameter. The smallest we make is Micro, then Small, Medium, Large, X Large...and extra long/ but with a medium width tube -Arborist. (This is a very specialized size for a very specialized set of splices...most arborists will do well with our regular wands). You can get an idea of the diameter of each of the wands by looking at the photo above - I put a pencil and a ruler in the photo to give perspective.

Arborist Splicing Wand - which is a Medium diameter wand cut extra long and which works rope 5/16" - 1/2" in diameter. This wand is especially good for split tail arborist splices. (12 ounce)

For 3-Strand & Mega Braid rope. This is the world"s second most expensive fid; the most expensive being those fids that cut and disturb your rope as you use them!

The Phid is round and polished with no sharp edges to damage the rope fibers. It is easy to enter, even into hard-laid rope. The Phid is designed with an artful �cutaway 148;, so you can leave it in the rope while tucking the strand; no more yanking and dragging to get the strand home.

The Phid is truly a beautiful tool, a marvel of functional elegance. The Point Hudson Phid comes in two sizes - Small works rope 5/16-5/8; Large works rope 3/4-1 1/8

In this volume of the Working Rope series, Brion Toss and Margie McDonald bring to you the distilled results of decades of experience with thousands of splices.

Here are the tips, techniques, and shortcuts that professionals use, along with valuable information on the characteristics of each type of rope you�ll be splicing.

There are no confusing �fid lengths� here, just dimensions based on rope diameter, or on marks braided into the rope at the factory. And the purpose or every mark is explained, so you can comprehend each splice, from start to finish.

You�ll find instructions for splicing conventional ropes, like Dacron and Nylon. But this volume also covers splices for the new High-Modulus lines like Spectra and Vectran. There are even instructions for making High-Modulus rope grommets.

Make no mistake, splicing is still an art, requiring patience and dedication on the part of the splicer. But with these instructions, you�ll be taking a giant step towards mastering braided rope splicing.

Great splice for running and standing rigging, life lines, slings, outhauls and more...Properly done, this splice will approach 100% efficiency in strength and security.

A sturdy 6 inch spike of the Best quality steel, with duck bill point for smooth insertion. Small enough for tiny line, strong enough for splicing steel wire. Solid wood varnished handle.

"A 4 inch version of our popular hand spike of the BEST quality steel, with duck bill point for smooth insertion. Small enough for tiny line, strong enough for splicing steel wire. Solid wood handle - shaped to your hand & varnished

Keep your rope ends from fraying - finish the job - whip them with a palm and needle whipping or a double constrictor knot (pg. 78 in the Rigger"s Apprentice). Mark them distinctly and traditionally with your choice - Dark Red, Dark Green, Deep Blue, White, or Gold. Also great for tying up very small packages.