wire rope break factory
Even though wire ropes are strong and reliable does not mean they are unbreakable. They can break or damage due to constant pressure or overuse. When using wire ropes you want to make sure to check them daily for damage and wear.
You can avoid the above problems by practicing proper rope maintenance procedures. On the other hand, some issues cannot be avoided so frequent inspections and checks should be done to ensure the wire rope is safe for use.
If you are worried about the conditions of your wire rope, you can implement a statutory life policy. This states that your ropes are to be retired at predetermined dates. Or you can do a retirement clause – which will allow you to use cables until they have deteriorated beyond a certain point.
Don’t wait until your wire ropes are damaged and broken, keep up with the health of your ropes! If you think you’re due for new wire ropes or an inspection, call the experts atSilver State Wire Rope and Rigging! We have a reputation for our high-quality, well-informed solutions, efficiency, and professionalism.Call usfor all your wire rope needs!
Example: Severe crown wire breaks on a 10-strand overhead crane wire rope. Crown breaks originate at the OUTSIDE of the rope at the contact point between rope and sheave/drum.
Remove the rope from service even if you find a SINGLE individual wire break which originates from inside of the rope. These so called VALLEY breaks have shown to be the cause for unexpected complete rope failures.
These 3 picture show what happens when you connect a left-lay rope to a right-lay rope, as done with this boom pendant extension. Both ropes are opening up to the point where the strands are nearly parallel to each other; they completely untwisted themselves and developed excessive wire breaks.
The result of such non-tensioning of the layers are looping of individual wires, completely crushed strands, total deterioration of a non-rotating rope due to gross neglect of inspection procedure.
NOTE: For a more indepth discussion on wire rope discard and inspection we suggest to attend our “Wire Rope” and “SlingMax® Rigger’s Mortis Seminar”. Call 1.800.457.9997 for details and dates.
In 1998, a crane load line broke while lifting the south topside module of the Petronius platform, dropping the module into the Gulf of Mexico. The cost was estimated to be around 116 million US dollars. Since 1999 more than 60 people have been killed as a result of wire ropes breaking and more than 65 associated injuries.
Not many people appreciate that there are literally thousands of wire rope designs, most of which can be put into a specific category. According to BS ISO 4309 2010 there are currently more than 25 categories of crane wire rope, each with differing characteristics and also different discard criteria. Deterioration can be measured, counted or calculated and the wire rope eventually taken out of service based on sophisticated discard criteria published in chosen standards, codes of practice or users handbooks.
Unfortunately there is no simple answer to either of these questions. All wire ropes will eventually break due to corrosion, wear or fatigue even if they are maintained and used properly. Unpredictable wire rope failures will inevitably occur, quite often when you least expect it if the discard criteria is ignored, or those using the equipment are ignorant of it.
James Dawes of Topeka, Illinois, was killed in 2008 after being struck by the boom of a Link-Belt crane; the accident was caused by the boom hoist wire rope breaking. The crane rope had been inspected, but a report said that the inspector failed to reject the rope showing a high number of visible wire breaks. Premature or unexpected wire rope failures can also be attributed to poor manufacture, incorrect handling and storage, poor installation technique, poor selection or fitting of its termination, infrequent or inadequate inspection and poor maintenance. Of course there is always the possibility that mechanical damage can occur and this is usually attributed to human error.
It is necessary, particularly during offshore operations that frequent inspections are carried out over the whole length of the working part of all steel wire ropes. The frequency of inspections should be based on the severity of use and risk assessment and particular attention should be paid to the critical areas of the wire rope; areas that are frequently running over sheaves, compensating sheaves and the rope termination to name a few.
If a wire rope has not been subjected to an abnormal environmental condition such as excessive heat, chemical attack or any corrosive solution and it has not been the victim of any form of mechanical damage, then trained operatives and inspectors can reasonably predict the length of time the steel wire rope is likely to last. That prediction, of course, will be dependent on the knowledge and experience of those making it coupled with known facts about the rope, its current condition and the application it is running on. The Inspector should be aware of the previous rope’s history, capacities of loads and the reeving systems employed together with the frequency of use etc.
Various standards and codes of practice have been written by recognized bodies and institutes based on the experience of experts or representatives of corporate organizations who have a vested interest. These standards do offer guidance on when a wire rope should be removed from service based on wear, abrasion and fatigue amongst others things, but none of these standards have any legal status except when they are called up by contract. Indeed they can all be supported or overturned in a court of law by an expert.
The users handbook, or more importantly the safe use instructions do have legal status. In many parts of the world these days, suppliers of cranes or any machinery for that matter, issue safe use instructions with new equipment. Modern applications employ modern wire rope and, in some cases, sheaves and pulleys that are made with materials other than steel. Original equipment manufacturers of such applications may impose discard criteria for the wire rope that is stricter than those in chosen standards. By law the user must follow manufacturers’ instructions.
Wire ropes will deteriorate much more quickly if they go dry and are allowed to remain in that condition. Tests have proven that a dry rope will lose up to 60 % of its expected life if it is not re-lubricated. There are differing schools of thought as to how wire rope should be lubricated. Some believe that a thin lubricant should be applied using a paintbrush. It is thought that this method allows the lubricant to penetrate. Experience has proven however, that thin penetrative lubricants will easily drain away or fly off in hot climates.
Another school of thought, and the one I stand on, is that grease should be pressure lubricated into the rope. This method, if applied properly, will ensure that the grease penetrates the rope pushing out the old lubricant with it and any possible corrosive agents such as salt water and sand. Any lubricant that is used must be compatible with the type that was applied previously and it is a good idea to consider the environment as well.
In any event, wire ropes usually announce that they are about to break. A series of individual wire breaks can be heard. These are likely to go on over several seconds and continuing for up to ten minutes before ultimate failure. Therefore, if operatives understand the warning signals, expensive incidents could be avoided.
Figure 2 shows two pieces of the same rope, the bottom portion quite clearly shows a progression of wire breaks. The operator was able to put the load down before disaster struck. The root cause of this fault was core deterioration brought about by internal corrosion.
To answer the other question on accountability, the list is extensive. Usually the first suspect is the wire rope manufacturer and that may be where the problem lies, but very often that is not the case. What if you were supplied the wrong rope for the application? Maybe you ordered the wrong rope or your buyer bought it from a cheap unapproved manufacturing source.
Perhaps your supplier is responsible, maybe he provided you with a rope that was produced to the wrong specifications. Would you know the difference? Perhaps you were sold a rope that had been stored in the suppliers or manufactures stock for a number of years and, whilst it was there, it hadn’t been properly maintained. Maybe the rope had been badly handled or installed incorrectly. The list of possibilities is endless.
In 1999 a ropeway in the French Alps snapped causing 21 deaths. In 2003, a ropeway wire rope snapped and 7 people died and a further 42 were injured. In 2007 a crane wire rope snapped at New Delhi’s metro, the entire structure tumbled down crushing workers underneath, six people were killed and 13 more were injured. In 2009 26 people were killed and 5 people were injured when a rope failed in a mine and a further 6 people were injured when a lift rope broke inside London’s Tower Bridge.
If you find yourself in the unfortunate situation after the unthinkable premature failure of a wire rope, then you might like to know that there are independent analytical services capable of determining probable cause. One of these is Doncaster Analytical Services Ltd (DAS), they have an independent metallurgical laboratory providing factual analysis and testing of wire rope for any reason (contact Mr Shui Lee, Technical Director, Tel +44(0)1302 556063, email: shui.lee@doncasteranalyticalservices. com).
You do not need a wire rope to fail in order to learn. Careful analysis of discarded ropes can also give you valuable information about your application, the way it operates, and the rope you have been using.
Based on this information, a trained, skilled and experienced inspector will be able to advise on a better crane or wire rope design, or to an improvement in maintenance procedures and safety.
Wire rope manufacturers produce their products in order to provide a high load capacity, versatile alternative to weaker ropes like manila rope or hemp rope. Wire rope products are used for a wide variety of motion transmission applications, among them: lifting, baling, tie down, hoisting, hauling, towing, mooring, anchoring, rigging, cargo control, guidance and counterbalance. They can also be used as railing, fencing and guardrailing.
Wire rope is a must-have for many heavy duty industrial applications. From mining to forestry to marine and beyond, there’s wire rope for almost every job. Some of the many industries in which wire rope is popular include: construction, agriculture, marine, industrial manufacturing, fitness, sports and recreation (plastic coated cables for outdoor playground equipment and sports equipment), electronics, theater (black powder coated cables for stage rigging), mining, gas and oil, transportation, security, healthcare and consumer goods.
Wire rope as we know it was invented just under 200 years ago, between 1831 and 1834. At that time, the goal was to create a rope strong enough to support work in the mines of the Harz Mountains. Invented by Wilhelm Albert, a German mining engineer, this wire rope consisted on four three-stranded wires. It was much stronger than older rope varieties, such as manila rope, hemp rope and metal chain rope.
While studying at Freiburg School of Mines, a man named L.D.B. Gordon visited the mines in the Harz Mountains, where he met Albert. After he left, Gordon wrote to his friend Robert Stirling Newall, urging him to create a machine for manufacturing wire ropes. Newall, of Dundee, Scotland, did just that, designing a wire rope machine that made wire ropes with four strands, consisting of four wires each. After Gordon returned to Dundee, he and Newall, along with Charles Liddell, formed R.S. Newall and Company. In 1840, Newall received a patent for “certain improvements in wire rope and the machinery for making such rope.”
In 1841, an American manufacturer named John A. Roebling began producing wire rope for suspension bridges. Soon after, another set of Americans, Josiah White and Erskine Hazard, started incorporating wire rope into coal mining and railroad projects, forming Lehigh Coal & Navigation Company (LC&N Co.). In 1848, wire rope from their wire rope factory in Mauch Chunk, Pennsylvania provided the lift cables needed to complete the Ashley Planes Project. This project sought to improve the performance and appearance of the freight railroad that ran through Ashley, Pennsylvania, by adding lift cables. This increased tourism and increased the railroad’s coal capacity. Before, cars took almost four hours to return; after, they took less than 20 minutes.
Wire rope likewise changed the landscape (again) in Germany, in 1874, when an engineering firm called Adolf Bleichert & Co. used wire rope to build Bi-cable aerial tramways. These allowed them to mine the Ruhr Valley. Several years later, they also used wire rope to build tramways for the German Imperial Army and the Wehrmacht. These tramways were wildly successful, opening up roads in Germany and all over Europe and the USA.
Since the 1800s, manufacturers and engineers have found ways to improve wire rope, through stronger materials and material treatments, such as galvanization, and different rope configurations. Today, wire rope makes possible many heavy industrial processes. It has become a necessity of the modern world.
Strands are made by tightly twisting or braiding individual wire together. One strand could have anywhere between two and several dozen wire filaments depending on the necessary strength, flexibility, and weight capacity.
One of the most dynamic elements of wire cables is the inner core. The strands are wrapped around the core, and it can be made of different metals, fibers, or even impregnated fiber materials. For heavy applications, cores are often made of a different strand of wire called an independent wire rope core (IWRC). An IWRC has a considerable amount of flexibility and it is still very strong. In fact, at least 7.5% of the strength increase in a wire rope can be attributed to an IWRC.
While they sometimes use other metals, like aluminum, nickel, copper, titanium, and even bronze for some applications, manufacturers primarily produce wire rope from steel. This is because steel is very strong and stretchable. Among the most common types they use are: galvanized wire, bright wire, stainless steel and cold drawn steel.
Of the wire rope steels, cold drawn carbon steel wire is most popular, although stainless steel wire rope is sometimes employed as well. Stainless steel rope is most popular for its anti-corrosive properties. Bright wire rope, a type of ungalvanized steel wire rope, is also popular. For added strength and durability, galvanized steel wire rope/galvanized steel cables are a very popular choice. Galvanized aircraft cable, for example, is always a must in aerospace.
When choosing or designing a custom wire rope for your application, suppliers consider factors such as: the environment in which the rope will function, required rust resistance, required flexibility, temperature resistance, required breaking strength and wire rope diameter. To accommodate your needs, manufacturers can do special things like: make your rope rotation resistant, color code your rope, or add a corrosion resistant coating. For instance, sometimes they specially treat and coat a cable with plastic or some other compound for added protection. This is particularly important to prevent fraying if the wire rope is often in motion on a pulley.
Manufacturers and distributors identify the differences in wire cable by listing the number of strands and the amount of wires per strand so that anyone that orders understand the strength of the cable. Sometimes they are also categorized by their length or pitch. Common examples of this include: 6 x 19, 6 x 25, 19 x 7, 7 x 19, 7 x 7, 6 x 26 and 6 x 36.
More complex wire rope identification codes connote information like core type, weight limit and more. Any additional hardware like connectors, fasteners, pulleys and fittings are usually listed in the same area to show varying strengths and degrees of fray prevention.
Cable wire rope is a heavy-duty wire rope. To give it its high strength, manufacturers construct it using several individual filaments that are twisted in strands and helically wrapped around the core. A very common example of cable wire rope is steel cable.
Spiral rope is made up an assemblage of wires with round or curved strands. The assemblage features at least one outer layer cord pointed in the opposite direction of the wire. The big advantage of spiral ropes is the fact that they block moisture, water and pollutants from entering the interior of the rope.
Similarly, stranded rope steel wire is made up of an assemblage of spirally wound strands. Unlike spiral rope, though, its wire patterns have crisscrossing layers. These layers create an exceptionally strong rope. Stranded rope may have one of three core material types: wire rope, wire strand or fiber.
Wire rope chain, like all chains, is made up of a series of links. Because it is not solid, wire rope chain is quite flexible. At the same time, it is prone to mechanical failure.
Wire rope slings are made from improved plow wire steel, a strong steel wire that offers superior return loop slings and better security. The plow wire steel also shields rope at its connection points, which extends its working life. Wire rope slings, in general, provide their applications with increased safety, capacity and performance. Wire rope sling is a rope category that encompasses a wide range of sub-products, such as permaloc rope sling, permaloc bridle slings and endless slings. These and other wire rope slings may be accompanied by a wide variety of sling terminations, such as thimbles, chokers and hooks.
Wire rope offers its user many advantages. First, design of even distribution of weight among strands makes it ideal for lifting extremely heavy loads. Second, wire rope is extremely durable and, when matched properly to the application, can withstand great stress and elements like corrosion and abrasion. In addition, it is very versatile. Its many iterations and the ways in which the rope can treated means that users can get rope custom fit for virtually any application.
Depending on the type of wire rope with which you are working and your application, you may want to invest in different accessories. Among these accessories are: wire rope clips, steel carabiners, fittings, fasteners and connections.
To ensure that your wire rope quality remains high, you must regularly inspect them for wear and degradation. The right wire rope should be selected for a particular use. Watch out for performance-impacting damage like: rust, fraying and kinks. To make sure that they stay in tip-top shape, you should also clean and lubricate them as needed. Check for this need as a part of your regular inspection.
Rope care is about more than inspection. It’s also about making an effort to use and store them properly every time you use them. For example, never exceed your rope’s rated load and breaking strength. Doing so will not only cause the weakening of your cable, but it may even cause immediate breakage. In addition, always store your wire rope cable in a dry and warm area, away from those elements that could cause premature rusting or other damage. Finally, always carefully wind your wire rope when you’re done with it, so as to avoid kinks. If you follow all these tips and treat your wire rope assemblies well, they will reward you with a long and productive service life.
Always make sure that you purchase wire rope that matches your industry and regional standards. Some of the most widely referenced standards organizations for wire rope include: ISO, ASTM International and OSHA. Talk over your specifications and application with your wire rope supplier to figure out what’s best for you.
If you’re in the market for a wire rope or a wire rope assembly, the best way to know you’re getting something that will both perform well and be safe if by working with a vetted professional. Find one among the list we’ve provided on this page. Check out their profiles to get an idea of the services and products they offer. Pick out three or four to whom you’d like to speak, and reach out. Talk to them about your specifications, standard requirements and budget. Ask about lead times and delivery options. Once you’ve spoken with all of them, compare and contrast their answers. You’ll know you’ve found the one when you talk to a wire rope company that is willing to go above and beyond for your satisfaction.
Wire rope strength in the United States is typically shown in tons of 2,000 lbs. The wire rope strength is shown as minimum breaking force (MBF). This is a calculated strength that has been accepted by the wire rope industry. When tested on a tensile machine, a new rope will break at a value equal to- or higher than – the minimum breaking force shown for that rope. The published values apply to new, unused rope. A rope should never operate at – or near- the minimum breaking force. The minimum breaking force of the rope must be divided by the design factor required for the application to determine the maximum load allowed on the rope. During its useful life, a rope loses strength gradually due to natural causes such as surface wear and metal fatigue.
Fatigue resistance involves fatigue of the wire used to make up a rope. To have high fatigue resistance, wires must be capable of bending repeatedly under stress – for example, as a loaded rope passes over a sheave during operation. Increased fatigues resistance is achieved in a rope design by using a large number of wires. It involves both the wire properties and rope construction. In general, a rope made of many wires will have greater fatigue resistance than a same – size rope made of fewer, larger wires because smaller wires have a greater ability to bend as a rope passes over a sheave or around drums. To overcome the effects of fatigue, ropes must never bend over sheaves or drums with a diameter so small as to bend wires excessively. Standard for specific applications contain requirements for minimum sheave and drum sizes. Every rope is subject to metal fatigue from bending stress while in operation, and therefore the rope’s strength gradually diminishes as the rope is used.
Crushing is the effect of external pressure on a rope, which damages it by distorting the cross-section shape of the rope, its strands or core -or all three. Crushing resistance therefore is a rope’s ability to withstand or resist external forces, and is a term generally used to express comparison between ropes. When a rope is damaged by crushing, the wires, strands and core are prevented from moving and adjusting normally during operation. In general, IWRC ropes are more crush
resistant than fiber core ropes. Regular lay ropes are more crush resistant than lang lay ropes. 6-strand ropes have greater crush resistance than 8-strand ropes or 19-strand ropes. Compacted strand ropes are more resistant than standard round-strand ropes.
When a load is placed on a rope, torque is created within the rope as wires and strands try to straighten out. This is normal and the rope is designed to operate with this load-induced torque. However, this torque can cause both single part and multiple part hoisting systems to rotate. Load induced torque can be reduced by specially designed ropes. In standard 6 and 8- strand ropes, the torques produced by the outer strands and the IWRC are in the same direction and add together. In rotation-resistant ropes, the lay of the outer strands is in the opposite direction to the lay of the inner strands, thus the torques produced are in opposite directions and the torques subtract from each other.
The increasing demand for higher breaking strength, greater flexibility, better rotation resistance and extended rope life cannot be met by general rope constructions. The discrepancy between expectation and operating “reality” has led to the development of High Performance wire rope constructions. The result is PYTHON, a high performance grade answer to the call for better durability, strength and flexibility. PYTHON High Performance wire ropes meet the rigors and demands of the industry and improve the overall output of the rope. It’s only fitting that professionals who seek better performance in the lifting, towing and rigging realm, call on the name and expertise of PYTHON wire rope.
are on the rise.Standard ropes often do not meet the high requirements of many applications of wire ropes. Higher demands for rope lifetime, break strength, rotation stability, flexibility, structural stability, and spooling behavior can only be
industry. Verope specializes in the manufacturing of High Performance Wire Rope for mobile cranes, crawler cranes, tower cranes, luffing cranes, foundation equipment and truck cranes.
As specialist for manufacturing quality steel wire ropes over 20 years, our company can supply strong, durable and reliable ropes that capable to minimize your downtime and maximize cost effectiveness. Decades of experience we owned make us know clearly the work you do and capable to provide professional guidance.
We select the best steel or stainless steel as raw material for wire rope manufacturing. Our products are manufactured under strict quality managements and test before they leave the factory.
Our engineers can provide professional advice about picking up optimal steel wire ropes for their application, installation guidance to ensure maximum return in their wire rope system.
If you are going to pick up steel wire ropes that suit your project perfectly, you must have an ideal about the construction about them. Our company can supply bright wire rope, galvanized wire rope, stainless steel wire rope, compacted wire rope, rotation resistant wire ropes, mining wire rope, elevator wire rope, crane wire rope and gas & oilfield wire ropes. Here are some details to solve the problem that may puzzle you whether you are browsing the web or picking up steel wire ropes.
Bright steel wire ropes mean no surface treatment is applied to the rope. Therefore, they have the lower price among these three wire ropes. Generally, they are fully lubricated to protect the rope from rust and corrosion.
Galvanized steel wire ropes feature compressed zinc coating for providing excellent corrosion resistance. With higher break strength yet lower price than stainless steel, galvanized steel wire ropes are widely used in general engineering applications such as winches and security ropes.
Stainless steel wire ropes, made of quality 304, 305, 316 steels, are the most corrosive type for marine environments and other places subjected to salt water spray. Meanwhile, bright and shiny appearance can be maintained for years rather than dull as galvanized steel wire ropes.
Steel wire ropes are composed of multiple strands of individual wires that surrounding a wire or fiber center to form a combination with excellent fatigue and abrasion resistance. These wires and strands are wound in different directions to from different lay types as follows:
Beside above lay types, alternative lay ropes which combine regular lay and lang lay together and ideal for boom hoist and winch lines, can also be supplied as your request.
Two main methods about seizing steel wire ropes in conjunction with soft or annealing wire or strands to protect cut ends of the ropes form loosening.
Manufacturing companies choose to use Dyneema rope over steel wire rope for heavy lifting applications such as heavy lift slings, crane rope, and other rigging operations because Dyneema rope:
Dyneema fiber rope is made from Ultra-High Molecular Weight Polyethylene (UHMWPE) fiber. Dyneema 12 strand rope is a common Dyneema fibered rope used for heavy-duty rigging applications. USA Rope & Recovery manufactures several different types of Dyneema fiber rope including the popular 12 Strand, and 24 Strand ropes, as well as others. No matter the application, USA Rope provides strong, durable, and efficient rope for the marine, arborist, nautical, off-roading, and other manufacturing industries.
More times than not, Dyneema fiber rope and steel wire rope are compared by most manufacturing companies–likeThe Rigging Company–for certain maritime, mooring, and towing rope applications. Pound for pound, Dyneema fiber rope is up to 15 times stronger than steel and up to 40% stronger than aramid fibers–otherwise known as Kevlar rope. The high-performance strength and low weight of Dyneema rope ensures that it is safer to use than steel wire rope. Ideally, Manufacturing companies want a rope that can withstand tremendous weight while being light enough to move, use, and work with when needed. Traditionally, steel wire rope is used for heavy-duty maritime, rigging, and mooring rope applications. Although steel wire rope is known for being used for heavy-duty rigging, the disadvantage is the serious risks that come from its heavy-weight and uneven breakage behavior. When a steel wire rope breaks, the combination of the enormous energy and incredible force causes unpredictable recoil. This unpredictable recoil comes from how wire rope is coiled. Essentially, wire rope is several strands of metal wire twisted into a helix, forming a composite rope. When breakage occurs, the helix formed rope unravels, creating a snaking behavior which can cause sharp edges of the broken strands to release at a dangerous force. The lack of strength compared to Dyneema rope shows that steel wire rope is more susceptible to breaking. This can increase risk factors for manufacturing companies that use steel wire rope for rigging, mooring, and heavy duty lifting.
For example, when comparing a ⅜ inch 12 Strand Dyneema rope to a ⅜ inch steel wire rope, the 12 strand Dyneema rope is significantly stronger and presents safer breaking characteristics. The ⅜ inch steel wire rope withstands a load of 14,478 pounds. As the video shows, even in the event of a partial rupture, the steel wire ropes higher mass and recoil provides a greater risk over 12 Strand Dyneema rope. With a ⅜ inch 12 Strand Dyneema rope, it can withstand 18,857 pounds. With the Dyneema fibers low mass and recoil, it reduces the risks for manufacturing companies using rigging rope for heavy-duty lifting applications.
Dyneema is 7 times lighter than steel wire rope at the same strength. In the event of a break, the recoil force is considerably less. Furthermore, the different construction of a Dyneema rope shows a linear recoil without any snaking behavior. This is due to the fact that Dyneema rope is manufactured from UHMWPE, which is comprised of extremely long chains of polyethylene oriented in the same direction, resulting in an overlapping effect. The overlapping of the UHMWPE increases the bond of the chains and thereby strengthens the Dyneema fiber. Dyneema rope offers durable characteristics that can withstand an immense amount of strength while having very little weight to the rope. Because Dyneema fiber is lighter and has a lesser impact when breakage occurs, choosing Dyneema rope over steel wire rope is the safer choice for manufacturing companies working with heavy lifting and below the hook rigging applications for the industrial, nautical, and arborist industries.
When choosing the best rope for any maritime, mooring, towing, or heavy-duty lifting application, choose a rope that can withstand extremely heavy loads and has a long enough lifetime to handle external factors in the nautical, industrial, or arborist industry. In order to decide which rope is best for the job, there are four main challenges that rigging, heavy-duty lifting, mooring, and towing ropes need to overcome:
Dyneema rope is the only high modulus synthetic fiber that has been scientifically engineered–from Ultra-High Molecular Weight Polyethylene (UHMWPE)–to overcome all four of these challenges. Dyneema is the world’s strongest fiber producing ropes that are 15 times stronger than steel wire ropes of the same weight and has become one the most trusted fiber ropes over generic HMPE ropes and steel cable wire ropes for all rigging, maritime, mooring, and towing rope applications.
Manufacturing companies that work with maritime and mooring applications need a durable rigging rope to withstand the constant pulling that comes from the rope running through fairleads and over capstans. Also, in heavy-duty lifting and towing applications, ropes come in contact with rough surfaces such as chocks and the vessel’s deck. These applications can potentially provide severe abrasions to the ropes and degrade the exposed fibers, eventually breaking them. Choosing a Dyneema fibered rope provides manufacturers with a durable, lightweight rope that carries an abrasion lifetime that is four times longer than steel wire rope and rope made with regular HMPE and polyester. With Dyneema’s extended abrasion lifetime, manufacturers are choosing Dyneema rope over steel wire rope for all mooring, towing, maritime, and heavy-duty lifting applications throughout the nautical, arborist, and industrial industries.
Bending fatigue occurs every time a rope flexes under tension. For heavy-duty lifting applications, rope experiences potential bending-fatigue every time something needs to be moved. For example, when a steel beam manufacturer has completed a 15-ton custom-made beam for a military-grade application, the finished product needs to be moved onto a truck for shipment. Rigging ropes are then attached to a crane to then lift, move and place the steel beam from the warehouse to the truck. This can wear out the rope. Another example is when the rope runs over fairleads and pedestals in maritime and mooring applications. This stresses the fiber both inside and outside of the rope causing bending fatigue and decreases the useful life of the rope. Certain conditions in towing and mooring applications can also lead to compression fatigue. This happens when ropes become slack during services and the fibers compress. Due to the molecular properties (UHMWPE) engineered to make Dyneema fiber– and its extremely long chains of polyethylene oriented in the same direction–threats of compression and bending fatigue are far less over other synthetic fibers and steel wire ropes.
In all rigging applications, synthetic ropes elongate when over a long period of time when loaded in higher temperatures–commonly referred to as creep. Creep is irreversible and when combined with abrasions or other risks, it can lead to rope failure. With regular HMPE rope, in heavy-duty lifting and towing applications where high loads and high temperatures are constantly a factor, the creep process can accelerate. This can be a major risk for ropes made from generic HMPE. In contrast, Dyneema rope has up to four times longer creep lifetime. When comparing Dyneema fiber to Spectra, another synthetic fiber rope, under 122 degrees Fahrenheit and 600 MPa load, Dyneema rope has a significantly longer creep lifetime than Spectra fiber rope.
eAfter comparing Dyneema rope to steel wire rope–a ⅜ inch 12 Strand Dyneema rope to a ⅜ inch steel wire rope–there is a guarantee that Dyneema rope is 15 times stronger and better at dealing with abrasions over steel wire rope. For manufacturing companies, Dyneema rope is also considered to be superior to Nylon rope due to Dyneema fiber having low ability to stretch, is UV resistant, and possesses an immense amount of strength. USA Rope properly manufactures Dyneema fibered ropes that are synthetically engineered to uphold incredible weight while enduring constant friction for application uses involving heavy-duty lifting, crane rope support, and below the hook rigging.
Understanding that Dyneema fiber rope is better used for manufacturing companies over steel wire rope, USA Rope & Recovery works hard to manufacture the highest quality rope by using top-of-the-line supplies from across the USA. Dedicating time and effort to finding the next best and technologically advanced products in the market is our main goal at USA Rope in order to help our customers gain the best competitive advantage in their respective field. USA Rope & Recovery also manufactures additional ropes including Spectra, Nylon, Polyester, Polypro, and Kevlar (Aramid) fiber ropes. No matter the application, USA Rope is a leader in custom rope manufacturing for industries including nautical, industrial, arborist, and marine.
In general, running rigging should be replaced whenever it shows visible signs of damage – core hemorrhaged through the cover, several broken strands close together, “rot” from UV exposure, or green and stiff from disuse. There’s a rule of thumb, but it varies rigger to rigger. The Rule of thumb says to replace all rigging hardware every 5-10 years. However, depending on how much everyday usage, weight, and environmental factors the rigging ropes take on can make the rule of thumb shorter or longer.
For customers who require peak rope performance levels in mission critical applications, Casar manufactures and supplies highly-engineered ropes that exceed industry standards while providing record-setting service life.
Our proprietary and innovative German-engineered rope designs deliver the highest levels of performance and safety, superior breaking strength values, the highest bending fatigue resistance, superior crushing resistance, and the best rotational resistance characteristics for high lifts.We have decades of global experience and on-site engineering support in the crane, OEM and underground mining sectors.
CASAR has an extensive range of products available and we can customize to your application.Our wire rope specialists will assist customers in design, selection, installation and operation to improve rope performance and maximize service life.
Wire ropes are largely used in marine environment or for rigging purposes. They receive considerable loads and thus suffer a great deal of mechanical damage throughout their service life. Moreover, research has shown that the major cause of wire rope failure is excessive deterioration and corrosion, lack of maintenance and inspection, and wrong usage resulting in early discarding, reduced safety and replacement cost increase.
Sometimes damage can be easily detected, while in other cases fractured wires may occur on the inside. Hence, wire ropes should be inspected and maintained by the right person (competent person assigned by the company), to assure they’re in perfect condition. Regular inspectionsensure high rope performance, long service lifetime , safety of personnel and equipment, and reduced operating costs.
All ropes (synthetic, high modulus and wire ropes) should be inspected before and after an operation. This guideline ensures maximum safety for both a ship’s personnel and equipment. Even though it’s difficult to determine the exact service life span of ropes, there is a way to have a more precise estimation about their efficient lifecycle. Calculating the exact time ropes have been in use (e.g mooring time, mooring conditions, weather and tidal conditions) is the answer. All in all, rope inspections should occur at least once a year.
Inspecting wire ropes in particular, comes with great responsibility. Inspection results should be recorded, and any defects noticed have to be reported and addressed properly. Some defects can be repaired, while in some cases replacing a wire rope is inevitable.
Periodical inspections ofvessel deck equipment is also crucial for maintaining the good condition of wire ropes. The condition of the drum, chocks, bitts, rollers, sheaves, cable clamps and other end fittings, affect the rope’s performance, threads and cords. Make sure to mark these parts during your overall inspection.
In order to help marine officers and staff conduct successful wire rope inspections – and keep an up-to-date record of them – we have created an inspection solution that helps in maintaining and monitoring a ship’s ropes and deck equipment.
When calculating mass using F = Minimum Breaking Force, according to the wire rope’s diameter, you can determine the Minimum Breaking Massand therefore the wire’s max strength. When calculating mass using F = Safe Load according to the wire rope’s diameter, you can determine the Safe Load Mass,which is the advised load for this rope diameter.
The strands of a wire rope absorb the majority of the tensile force applied on the rope. Their design and manufacturing standards affect the level of fatigue resistance and resistance to abrasion. An easy way to understand which rope design is suitable for each purpose, is the wire rope classification.
Wire ropes are classified according to the number of strands in each construction and the number of wires in each strand. For example, a classification of 6X19 means that a wire rope of this type always has six strands, but its wires could be 15-26 per strand. This is because 19 is not the exact number of wires, but the classification of a wire number range.
Visual inspections are a common and fast way to assess wire rope condition. Both the standard and rotation resistant wire rope inspectionprocesscomply with the same four steps of examination. A ship’s crew can perform them as follows:
Steel wire rope distortion is obvious in most cases and can easily be identified by the inspector or the ship‘s crew. It usually occurs if load is suddenly applied or abruptly released (shock loading), or even if swift torque is forcefully induced.
Although not all of these deformations make the rope absolutely dangerous to use, they all may cause ropes to wear unevenly in time. This means inspections should take place more often, and distorted ropes should be handled with caution.
The rag and visual inspection is a good method for regular inspection intervals. The inspector pulls a rag along the rope trying to find broken wire cords. If the rug gets snagged by the rope, the inspector has to stop and assess the wire rope’s condition. Extreme caution should be exercised during the visual inspection, and under no circumstances should this method be the only one used to inspect wire ropes.
Tip: When you encounter a protruding wire end, bend it back and forth manually, until it separates from the wire. This will protect neighboring wires from wearing out.
Diameter reduction is a critical factor in steel wire rope wear and if not properly taken care of, it can result in rope breakage. Excessive abrasion, loss of core mass, corrosion or inner wire failure are all factors that contribute to diameter reduction.
To get an accurate measurement of the rope’s diameter, measure the rope at three different points at least 5 feet apart. Take the average of these three measurements to determine the true diameter.
Any measurements showing a reduction of ⅓ or more, indicate that a replacement should follow without delay. A diameter reduction of less than 1/3 still requires attention, and the inspector or the ship’s crew should be on guard in the next scheduled wire rope inspection.
Failure from abrasion or corrosion is a result of deficient deck equipment inspection or insufficient wire rope lubrication respectively. Internal corrosive damage is more difficult to identify than any other types of degradation. In most cases, the damage has progressed more than the external signs suggest.
Wire rope storage plays a significant role in the rope’s operation life.Wire rope corrosion and pitting can be avoided if ropes are safely stored in a clean, cool, dry and well-ventilated place. Steel wire ropes should not by any means rest on the floor, and should be protected from water, dust or any chemical fumes. Long term storage requires periodic greasing, turning the reel upside down for preventing grease dripping and possibly re-winding to another reel with larger inner tube diameter.
Wire ropes should be maintained with periodical lubrication. In order to prevent internal corrosion, a pressure lubricator is suggested to be used. In this case, a small amount of grease is used to lubricate the rope internally, while the deck stays grease-clean. Pressure lubricators clean the rope before they grease it so that the new grease enters a clean rope. The type of grease used is very important for maximum protection and greasing efficiency.
Steel wire ropes exposed to dirt, grime and other contaminants, have to be cleaned with a wire brush and petroleum (unless a pressure lubricator is used). Optimal cleaning of wire ropes can extend their service life and guarantee safe operations.
The reeling process is of high importance for the longevity of wire ropes. To protect them from being damaged, it is important that the surface of the drum is clean, smooth and dry. Improper reeling may cause wire-rope strands to spread or get flattened, when in contact with one another, as successive layers are being spooled and upper layers apply pressure on the lower ones.
Katradis S.A. offers a wide range of top quality wire ropes for shipping (mooring and hoisting operations), fishing and construction purposes. Our wire ropes have greater resistance to fatigue, and they distribute tension force equally among the rope strands. They are less likely to kink, providing higher staff safety and assuring operation success.
Welding two ropes together is common in the steel industry. If properly done, welding may develop sufficient strength to complete the rope installation. However, the welded portion of the rope is rather stiff, and the welded steel wire material may become brittle. Since the welded portion has to pass over sheaves, there is the danger that the weld may break.
If installing Python® wire rope as well as all non-rotating types we do not recommend the welding procedure. Welding might damage the seizings and the rope may unravel getting damaged beyond repair.
A common method for heavy crane rope installations. A steel sleeve only slightly larger than the rope diameter is swaged on to the rope end and a small auxiliary cable protrudes from the sleeve. Either, the old rope is furnished also with a becket loop, or the old rope will be connected to the becket loop with a cable grip.
Non-rotating rope must be installed with a swivel between old and new ropes. The old rope may have developed torque during it’s working life and we must ensure that this torque is not transferred to the new rope.
Python® types Multi and Super 8 may be installed with a swivel. In fact, if you have to change either of these constructions for a 6-strand rope, particularly when this rope has a different lay direction, a swivel is of definite benefit.
Python® Power 9 and Python® Ultra must not be installed with a swivel. Doing so will unlay the rope and damage it beyond repair. Use two cable grips and connect them with an auxiliary cable.
When using cable grips, the end of the grips have to be tightly seized on to the rope body to prevent accidental slip-out of the rope. Alternately, you may wrap the grip end with a strong reinforced industrial strength adhesive tape.