types of wire rope breaks manufacturer

The cable on a crane moves through a series of motorized pulleys that are controlled by the crane operator to raise and lower items. For safety reasons, a crane usually has several wire rope cables that are attached to the object being lifted. This helps to prevent putting too much strain on a single cable.

To create wire rope cable, manufacturers begin with long strips of high tensile strength metal that are tightly woven together into strands. A large majority of wire rope cables are constructed using steel due to its durability and strength. Several strands are then spun and pressed tightly together into a helix using a machine.

The newly created wire rope cable is then rolled up onto a spool and shipped out, or it is rolled up onto a pulley to be used with a brand new piece of heavy equipment.

Stationary ropes bear tensile forces and are loaded with fluctuating levels of stress. These are the types of cables that would be found on a suspension bridge.

Finally, wire rope slings (also called stranded ropes) are used to harness all kinds of goods. These are bent over sharp edges of goods to hold them in place.

Original equipment wire rope and replacement wire rope must be selected and installed in accordance with the requirements of this section. Selection of replacement wire rope must be in accordance with the recommendations of the wire rope manufacturer, the equipment manufacturer, or a qualified person.

Wire rope design criteria: Wire rope (other than rotation resistant rope) must comply with either Option (1) or Option (2) of this section, as follows:

Option (1). Wire rope must comply with section 5-1.7.1 of ASME B30.5-2004 (incorporated by reference, see § 1926.6) except that section"s paragraph (c) must not apply.

Option (2). Wire rope must be designed to have, in relation to the equipment"s rated capacity, a sufficient minimum breaking force and design factor so that compliance with the applicable inspection provisions in § 1926.1413 will be an effective means of preventing sudden rope failure.

Type I rotation resistant wire rope ("Type I"). Type I rotation resistant rope is stranded rope constructed to have little or no tendency to rotate or, if guided, transmits little or no torque. It has at least 15 outer strands and comprises an assembly of at least three layers of strands laid helically over a center in two operations. The direction of lay of the outer strands is opposite to that of the underlying layer.

Type II rotation resistant wire rope ("Type II"). Type II rotation resistant rope is stranded rope constructed to have significant resistance to rotation. It has at least 10 outer strands and comprises an assembly of two or more layers of strands laid helically over a center in two or three operations. The direction of lay of the outer strands is opposite to that of the underlying layer.

Type III rotation resistant wire rope ("Type III"). Type III rotation resistant rope is stranded rope constructed to have limited resistance to rotation. It has no more than nine outer strands, and comprises an assembly of two layers of strands laid helically over a center in two operations. The direction of lay of the outer strands is opposite to that of the underlying layer.

Type I must have an operating design factor of no less than 5, except where the wire rope manufacturer and the equipment manufacturer approves the design factor, in writing.

When Types II and III with an operating design factor of less than 5 are used (for non-duty cycle, non-repetitive lifts), the following requirements must be met for each lifting operation:

A qualified person must inspect the rope in accordance with § 1926.1413(a). The rope must be used only if the qualified person determines that there are no deficiencies constituting a hazard. In making this determination, more than one broken wire in any one rope lay must be considered a hazard.

Each lift made under § 1926.1414(e)(3) must be recorded in the monthly and annual inspection documents. Such prior uses must be considered by the qualified person in determining whether to use the rope again.

Rotation resistant ropes may be used as boom hoist reeving when load hoists are used as boom hoists for attachments such as luffing attachments or boom and mast attachment systems. Under these conditions, all of the following requirements must be met:

The requirements in ASME B30.5-2004 sections 5-1.3.2(a), (a)(2) through (a)(4), (b) and (d) (incorporated by reference, see § 1926.6) except that the minimum pitch diameter for sheaves used in multiple rope reeving is 18 times the nominal diameter of the rope used (instead of the value of 16 specified in section 5-1.3.2(d)).

The operating design factor for these ropes must be the total minimum breaking force of all parts of rope in the system divided by the load imposed on the rope system when supporting the static weights of the structure and the load within the equipment"s rated capacity.

Wire rope clips used in conjunction with wedge sockets must be attached to the unloaded dead end of the rope only, except that the use of devices specifically designed for dead-ending rope in a wedge socket is permitted.

Prior to cutting a wire rope, seizings must be placed on each side of the point to be cut. The length and number of seizings must be in accordance with the wire rope manufacturer"s instructions.

A competent person must begin a visual inspection prior to each shift the equipment is used, which must be completed before or during that shift. The inspection must consist of observation of wire ropes (running and standing) that are likely to be in use during the shift for apparent deficiencies, including those listed in paragraph (a)(2) of this section. Untwisting (opening) of wire rope or booming down is not required as part of this inspection.

Significant distortion of the wire rope structure such as kinking, crushing, unstranding, birdcaging, signs of core failure or steel core protrusion between the outer strands.

In running wire ropes: Six randomly distributed broken wires in one rope lay or three broken wires in one strand in one rope lay, where a rope lay is the length along the rope in which one strand makes a complete revolution around the rope.

In rotation resistant ropes: Two randomly distributed broken wires in six rope diameters or four randomly distributed broken wires in 30 rope diameters.

In pendants or standing wire ropes: More than two broken wires in one rope lay located in rope beyond end connections and/or more than one broken wire in a rope lay located at an end connection.

If a deficiency in Category I (see paragraph (a)(2)(i) of this section) is identified, an immediate determination must be made by the competent person as to whether the deficiency constitutes a safety hazard. If the deficiency is determined to constitute a safety hazard, operations involving use of the wire rope in question must be prohibited until:

If the deficiency is localized, the problem is corrected by severing the wire rope in two; the undamaged portion may continue to be used. Joining lengths of wire rope by splicing is prohibited. If a rope is shortened under this paragraph, the employer must ensure that the drum will still have two wraps of wire when the load and/or boom is in its lowest position.

If a deficiency in Category II (see paragraph (a)(2)(ii) of this section) is identified, operations involving use of the wire rope in question must be prohibited until:

The employer complies with the wire rope manufacturer"s established criterion for removal from service or a different criterion that the wire rope manufacturer has approved in writing for that specific wire rope (see § 1926.1417),

If the deficiency is localized, the problem is corrected by severing the wire rope in two; the undamaged portion may continue to be used. Joining lengths of wire rope by splicing is prohibited. If a rope is shortened under this paragraph, the employer must ensure that the drum will still have two wraps of wire when the load and/or boom is in its lowest position.

If the deficiency (other than power line contact) is localized, the problem is corrected by severing the wire rope in two; the undamaged portion may continue to be used. Joining lengths of wire rope by splicing is prohibited. Repair of wire rope that contacted an energized power line is also prohibited. If a rope is shortened under this paragraph, the employer must ensure that the drum will still have two wraps of wire when the load and/or boom is in its lowest position.

Where a wire rope is required to be removed from service under this section, either the equipment (as a whole) or the hoist with that wire rope must be tagged-out, in accordance with § 1926.1417(f)(1), until the wire rope is repaired or replaced.

The inspection must include any deficiencies that the qualified person who conducts the annual inspection determines under paragraph (c)(3)(ii) of this section must be monitored.

Wire ropes on equipment must not be used until an inspection under this paragraph demonstrates that no corrective action under paragraph (a)(4) of this section is required.

At least every 12 months, wire ropes in use on equipment must be inspected by a qualified person in accordance with paragraph (a) of this section (shift inspection).

The inspection must be complete and thorough, covering the surface of the entire length of the wire ropes, with particular attention given to all of the following:

Exception: In the event an inspection under paragraph (c)(2) of this section is not feasible due to existing set-up and configuration of the equipment (such as where an assist crane is needed) or due to site conditions (such as a dense urban setting), such inspections must be conducted as soon as it becomes feasible, but no longer than an additional 6 months for running ropes and, for standing ropes, at the time of disassembly.

If the deficiency is localized, the problem is corrected by severing the wire rope in two; the undamaged portion may continue to be used. Joining lengths of wire rope by splicing is prohibited. If a rope is shortened under this paragraph, the employer must ensure that the drum will still have two wraps of wire when the load and/or boom is in its lowest position.

Wire ropes on vehicle lifting equipment come under a lot of strain during their life span. Fatigue related damage such as broken strands in the outer wires can be caused by numerous things. Typically these kinds of breaks are caused by the stress put on the parts of the rope continually running in or around pulleys and guides.

When a ramp is loaded and operated with a vehicle, the tension of the ropes increases causing extra stress to the outer core. If any of the outer wires our found to be broken or showing signs of wear, it is time to renew them.

Kinking of wire ropes is usually caused by poor manufacture of the layers winding process, or from pulleys becoming worn, causing the running surface to narrow and deform the ropes as they pass through. The usual signs of worn pulleys are small shards of steel filings around the base of the vehicle ramps upright posts.

Wire ropes that fail due to corrosion are usually caused by improper lubrication type or lack of regular maintenance.  Corrosion is easily identified by the pitted surface or rust patches on the external wires of the rope.  The extent of the damage to the interior core of the rope is very difficult to judge and due to this, corrosion is one of the most dangerous causes of rope deterioration.

Severe wear to a wire rope is identified as flat spots or signs of crushing in different points around the rope. These points are usually found in areas that constantly run around pulleys etc and can be a sign of slipping, overloading or narrowing of the ropes, causing damage to the running track of the pulleys. Other causes of wire rope wear, could be the bearings or sleeves inside the pulleys and pins becoming worn and causing the ropes to run at a slight angle to the pulley line.

Birdcage type damage to wire ropes can be caused by a multitude of scenarios. The most common is caused by the ropes twisting out of line, causing the internal core to break through the individual external wires. This can be caused by poor installation, or the fact that all the components the rope runs around or over are not aligned centrally.

If you require more information about wire ropes or to arrange for an engineer to visit your workshop to carry out a safety inspection, please get in touch with Straightset service.

All wire ropes will wear out eventually and gradually lose work capability throughout their service life. That"s why periodic inspections are critical. Applicable industry standards such as ASME B30.2 for overhead and gantry cranes or federal regulations such as OSHA refer to specific inspection criteria for varied applications.

You should thoroughly inspect all wire ropes at regular intervals. The longer it has been in service or, the more severe the service, the more thoroughly and frequently it should be inspected. Be sure to maintain records of each inspection.

Inspections should be carried out by a person who has learned through specialized training or practical experience of what to look for and who knows how to judge the importance of any abnormal conditions they may discover. It is the inspector"s responsibility to obtain and follow the proper inspection criteria for each application inspected.

Figure 1is what happens when a wire breaks under tensile load exceeding its strength. It"s typically recognized by the "cup and cone" appearance at the point of failure. The necking down of the wire at the point of failure to form the cup and cone indicates failure has occurred while the wire retained its ductility (the ability to change form without breaking).

Figure 2is a wire with a clear fatigue break. It is identified by the square end perpendicular to the wire. This break was produced by a torsion machine that"s used to measure the ductility. This break is similar to wire failures in the field caused by fatigue.

Figure 3 is a wire rope that has been subjected to repeated bending over sheaves under typical loads. This fatigue results in breaks in individual wires - these breaks are square and usually in the crown of the strands.

Figure 4 is an example of fatigue failure of a wire rope subjected to heavy loads over small sheaves. The breaks in the valleys of the strands are caused by "strand nicking." There may be crown breaks, too.

Figure 5 is a single strand removed from a wire rope subjected to "strand nicking." This condition is a result of adjacent strands rubbing against one another. While this is normal in a rope"s operation, the nicking can be accentuated by high loads, small sheaves or loss of core support. The ultimate result will be individual wire breaks in the valleys of the strands.

Wire breakshowsone end of broken wire coned, the other cupped. Necking down of the broken ends is typical of this type of break.Where tension breaks are found, the rope has been subjected to overloading, either for its original strength (new rope) or for its remaining strength in the case of a used rope. Tension breaks frequently are caused by the sudden application of a load to a slack rope, thereby setting up incalculable impact stresses.

Wire break shows broken ends worn to a knife-edge thinness.Abrasive wear obviously is concentrated at points where the rope contacts an abrasive medium, such as the grooves of sheaves and drums, or other objects with which the rope comes into contact. Unwarranted abrasive wear indicates improperly grooved sheaves and drums, incorrect fleet angle, or other localized abrasive conditions.

Wire breaksareusually transverse orsquareshowinggranularstructure.Oftenthese breaks will develop a shattered orjagged fracture, depending on the type ofoperation.Where fatigue breaks occur, the rope has been bent repeatedly around too small a radius. Whipping, vibration, slapping and torsional stresses also will cause fatigue. Fatigue breaks are accelerated by abrasion and nicking.

Easily noted by the wire"s pitted surface, wire breaks usually show evidence of tension, abrasion and/or fatigue.Corrosion usually indicates improper lubrication. The extent of the damage to the interior of the rope is extremely difficult to determine; consequently, corrosion is one of the most dangerous causes of rope deterioration.

Wirewill be pinched down and cut atbroken ends, or will show evidence of ashear-like cut.This condition is evidence of mechanical abuse caused by agents outside the installation, or by something abnormal on the installation itself, such as a broken flange.

Wire rope is a collection of metal strands that have been twisted and wound to form the shape of a helix with the purpose of supporting and lifting heavy loads and performing tasks that are too rigorous for standard wire. On shipping docks, rigging, and load bearing equipment, wire rope is attached to swivels, shackles, or hooks to lift a load in a controlled, even, and efficient manner.

The uses for wire rope include adding support to suspension bridges, lifting elevators, and serving as additional reinforcement for towers. The design of wire rope, with its multiple strands wrapped around a stable core, provides strength, flexibility, and ease of handling for applications that have bending stress.

Individual designs of wire rope involve different materials, wire, and strand configurations as a means for supporting and assisting in the completion of lifting or supportive applications.

The term wire rope encompasses a wide range of mechanical tools that are made to perform heavy and extreme lifting jobs. Wire rope is a complicated and complex tool with multiple moving parts capable of moving in unison. A 6 by 25 wire rope has 150 outer strands that move as one in an intricate pattern supported by a flexible core.

An essential part of the design of wire rope is the required clearance between the strands to give each stand the freedom to move and adjust when the rope bends. It is this unique feature that differentiates wire rope from solid wire and other forms of cable.

The basic element of wire rope is wire that is used to configure, shape, and form the rope. Typically, steel, stainless steel, and galvanized wires are the first choice with aluminum, nickel alloy, bronze, copper, and titanium being second possibilities. The choice of wire is dependent on the type of work the wire is going to be used to perform with strength, flexibility, and abrasion resistance being the major determining factors.

Stainless steel wire rope has all of the basic qualities of galvanized and general wire rope with the added benefits of corrosion and rust resistance; this makes it the ideal choice for harsh and stressful conditions.

Steel wire rope is classified as general purpose wire rope and comes in a wide variety of sizes, diameters, and strengths. It is the most common type of wire rope and is used for several industrial, manufacturing, and construction applications.

Before going further into the discussion of how wire rope is made, it is important to understand the numbers used to describe each type. All wire ropes have a core around which wires are wound. The various styles of cores vary according to the construction and design of the requirements of the wire rope that is being produced.

Wire rope is classified by the number of strands it has as well as the number of wires in each strand. The most common classification is a seven wire rope that has one strand in the center and six around its circumference. This type of wire rope is lightweight with a very simple construction. The majority of wire ropes are more complex and intricate with multiple intertwining strands and wires.

What must be understood about wire rope is that it has a complicated configuration. It is actually wires wrapped around wires to form bundles that are wrapped around other bundles. In the case of a seven wire wire rope, the core has bundles of wires wound around it; this can be seen in the image below.

The first step in wire rope creation is the production of wire strands where wires are wound around a single core wire. The number of wires included in the strand is dependent on the specified strength, flexibility, and size requirements of the rope. Once the strand is completed, it is straightened before being moved to wire rope construction.

Like wire ropes, strands have different patterns; patterns are the arrangements of the wires and their diameters. Though most strands have a core, there are strand patterns that have three or four wires without a core that are referred to as centerless strands. The design of each strand pattern is meant to enhance the strength of the wire rope and improve its performance.

For a multiple layer strand, the layers of wire are placed over one another in successive order. The placement of the wires on top of each other must be such that they fit smoothly and evenly.

The Warrington pattern is like the multiple layer pattern with one variation. Like the multiple layer pattern, the inner wires and the core are the same and have the same diameter. The difference is in the outer layer, which has wires of alternating sizes of large and small with larger diameter wires laying in the valleys of the inner wires.

All of the wires of a filler pattern are the same size. What makes this pattern unique is the insertion of small wires in the valleys of the inner wires to fill the gap between the inner and outer layer.

The flattened strand pattern is also known as the triangular strand, which can be triangular or oval. Three round wires form the core. The outer flattened surface has a greater sectional metallic area; this makes this pattern stronger and longer lasting.

The core of a wire rope runs through the center of the rope and can be composed of a variety of materials, which include synthetic fibers, natural fibers, a single strand, or another wire rope. The core supports the wound strands, helps maintain their position, is an effective lubricant carrier, and provides support.

Wire ropes with fiber cores are restricted to light loads and are not used in severe, harsh, or stressful conditions. Polypropylene and nylon are types of synthetic fiber cores and can be used in conditions where there is exposure to chemicals.

Cores made of wire are classified as independent wire cores. The core of a wire rope with a wire core is actually a wire rope with another wire rope serving as the core, as can be seen in the diagram below. These types of wire ropes are used where the rope will be exposed to exceptional resistance and crushing.

A strand, or wire strand core, is exactly like the rest of the strands of the wire rope with wires of the same diameter and size as the other strands.

The choice of core and creation of the strands are the simplest yet most essential parts of wire rope construction. Wire rope lays, the method used to wind the strands, is more complex and involves several choices.

Lay is a term used to describe three of the main characteristics of wire rope: direction, relationship, and linear distance. The strands can be wrapped around the core going right or left. Right or left refers to the direction of the strands wrapped around the core and the wires within the strands. The linear distance is how far a strand moves when it is making a revolution around the core.

In a regular lay, the wires and strands spiral in opposite directions. With a right hand regular lay, the wires spiral to the left and the strands to the right. In the left hand regular lay, the wires spiral to the right and the strands to the left. This type of lay is easy to handle but wears out quickly because the crown wires are in contact with the bearing surface.

In the Lang, or Albert, lay, the wires and strands spiral in the same direction with right hand lay being the most common. The wires in a Lang lay appear to run parallel to the center line of the rope. The difficulty with Lang lay wire ropes is handling since they tend to kink, twist, and crush.

Wire rope is an exceptionally strong tool that has been configured and designed to withstand the stress placed upon it through rigorous and continual use. In most applications, wire rope has to endure extreme stress and strain. It is for these reasons that coatings have been developed to protect wire rope from abrasions, corrosion, UV rays, and harmful and damaging chemicals.

Three main types of coatings are used to protect wire rope: polyvinyl chloride (PVC), polypropylene, and nylon. Of the three types, PVC is the most popular.

PVC is popular because it is multifunctional, extremely flexible, and general purpose as well as low cost. It has an operating temperature between -30° F (-35° C) and 180° F (80° C) with a hardness of 90 on the durometer.

In cases where there are severe and hazardous working conditions, polypropylene is the recommended choice since it is capable of protecting wire rope against corrosion and chemical leaching. Additionally, it is resistant to impact damage and abrasion. Polypropylene is a tough, rigid, and crystalline thermoplastic that is made from a propene monomer and is resilient as well as inexpensive.

Nylon is exceptionally abrasion resistant, which makes it ideal for use in cold environments. It is not as flexible as PVC but has excellent protection against corrosion and impact. It has excellent chemical resistance at temperatures between -65° F (-54° C) and 230° F (110° C) and is available in a wide assortment of colors, or it can be transparent.

Braided wires are electrical conductors made up of small wires that are braided together to form a round tubular braid. The braiding and configuration of braided wire makes them very sturdy such that they do not break when flexed or bent. Braided wires are widely used as conductors, are commonly made from copper due to copper"s exceptional conductivity, and can be bare or coated depending on the application.

Braided wire can be round and tubular or flat. Round tubular braids fit in most spaces where flat braided wire will not. Flat braided wire begins as round braided wire which is flattened on a capstan. They are exceptionally strong and designed for medical and aircraft applications.

Metals used to make wire rope are various grades of stainless steel, bright steel, and galvanized steel. Though the majority of wire rope manufacturers use these three metals, other metals such as copper, aluminum, bronze, and monel are also used on a limited basis.

The most important aspect of wire rope is the wire and the metal from which it is made. The strength and resilience of wire rope is highly dependent on the quality of metal used to make it, and these are essential factors to be considered when purchasing it.

Bright steel wire does not have a coating and is rotation resistant, (designed to not rotate when lifting a load). It is drawn from hot rolled rods that are put through a die to match its specific dimensional tolerances, mechanical properties, and finish. Bright wire is used as a single line in conditions that require a rope that will resist cabling.

Galvanized steel has a zinc coating for corrosion resistance and has the same strength and durability as bright steel. Environmental conditions determine the use of galvanized steel. In mildly severe and slightly harsh conditions, galvanized steel wire is an economical replacement for stainless steel.

In the manufacturing process, galvanized wire goes through the process of galvanization, a method of coating steel wire with a protective and rust resistant metal. Galvanized wire is exceptionally strong, rust resistant, and flexible enough to meet the needs of a variety of applications.

Stainless steel does not have the same strength and endurance as bright steel or galvanized steel but has the many benefits commonly associated with stainless steel, such as resistance to stains, wear, rust, and corrosion. More expensive than the other two metals, stainless steel has the added benefit of lasting longer and providing exceptional performance.

Wire rope made from copper is mostly used for electrical applications due to its exceptional electrical characteristics. The benefits of copper wire rope are its durability, flexibility, and resilience compared to standard copper wire. The strength of copper wire rope is seen in its use in applications where there are vibrations and shaking.

The wire rope lubrication process begins during its fabrication and continues during its use. Lubrication of wire rope is designed to lower the amount of friction it endures and provide corrosion protection. Continued lubrication increases the lifespan of wire rope by preventing it from drying up, rusting, and breaking.

The types of lubricants for wire rope are penetrating or coating with coatings covering and sealing the outside of the rope. Penetrating lubricants go deep into the rope and seep into the core where they evaporate to form a thick coating or film.

The application of the lubricant is dependent on the type of core. Fiber cores absorb the lubricant and serve as a reservoir that retains the lubricant for an extended period of time. With metal cores, the lubricant is applied as the wire is twisted into strands to give complete saturation and coverage of the wires.

Petrolatum compounds are translucent and provide excellent corrosion and water resistance. They tend to drip off at high temperatures but keep their consistency in cold conditions. Petrolatum is a mixture of hydrocarbons from the distillation of petroleum that belong to the methane family of hydrocarbons. It can be used in semi-solid or liquid form and forms a jelly in its semi-solid form.

Asphaltic compounds are a mineral based oil combined with bitumen to create a tacky, high viscosity lubricant with an undiluted viscosity. As a lubricant, asphaltic compounds create an oil film that separates the mating surfaces and are applied as a spray. Once applied, the meshing of surfaces causes the solvent to flash; this leaves a viscous coating of lubricant.

There are several types of greases that are used as wire rope lubricating agents and are made up of oil, a thickener, and additives. The essential components are the base oil and additives, which influence the behavior of the grease. The thickener holds the base oil and additives together. The amount of base oil in a grease is between 70% and 95% with an additive of 10%.

The additive in grease enhances the positive properties of the oil and suppresses the negative properties. Common additives are oxidation and rust inhibitors as well as pressure, wear, and friction reducing agents.

Of the many choices for lubricants, vegetable oil is the easiest to use and penetrates the deepest. The design of the additives for vegetable oils gives them the necessary qualities required to penetrate deep into a wire rope. The exceptional penetration provides protection against wear and corrosion. Since vegetable oil is a fluid, it helps in washing the wire rope to remove external abrasive contaminants.

Wire rope is widely used in machines, structures, and varied lifting applications. Its type, size, and requirements are determined by how it will be used. Regardless of its use, wire rope guarantees exceptional strength and provides high quality and excellent performance.

The lifting of heavy loads for centuries involved the use of hemp rope or chains, neither of which was a guaranteed or substantial method. Early in the 18th Century, between 1824 and 1838, Wilhelm Albert, a German mining engineer, combined the twisting of hemp and strength of chains to create today‘s wire rope.

The most common use of wire rope is as a part of a crane hoist wherein it is attached to the hook of the hoist and wrapped around a grooved drum. The tensile strength and durability of wire rope makes an ideal tool for lifting and keeping loads secure. Though it is used in several industries, it is very popular for production environments wherein materials need to be lifted quickly and efficiently.

In addition to its many lifting applications, the strength and stability of wire rope is useful in other applications, especially in the aerospace industry. Pedals, levers, and connectors in the cockpit of an aircraft are connected with wire rope. The wires provide for the passage of power between systems and mechanisms; this allows control of the aircraft. Wire rope is used to control propeller pitch, cowl flaps, and the throttle. It also assists in lowering and minimizing vibrations.

Tires are reinforced with wire rope to increase their durability and strength. All automotive production environments make use of wire ropes for supplying materials, moving heaving loads, and positioning equipment. Wire rope can be found in the production of steering wheels, cables, exhausts, springs, sunroofs, doors, and seating components.

As surprising as it may seem, the place that wire rope has the greatest use is in the home, where its strength, long life, endurance, and resilience provide guaranteed protection and performance. The main reason wire ropes are so popular for home use is cost.

Inexpensive, easy to obtain, easy to install, and easy to maintain, wire ropes provide an additional method for performing home repairs and structural support. Their excellent flexibility and sturdiness combined with their invisibility has made wire rope an ideal solution to several home maintenance issues. It is used to support staircases, fences, decks, and hang plants.

The search and production of crude oil has relied on wire ropes for centuries to lift drill bits, insert shafts, and support oil rigs on land and the water. When equipment, machinery, and tools have to be lowered into the depths of the earth and sea, wire ropes are the tool that the oil industry relies on to do the job.

Many of the tasks of oil production require tools that are capable of enduring severe and harsh conditions. Wire ropes have to withstand enormous pressure, extraordinary stress, and a wide range of temperatures. The use of wire rope includes maintaining oil rig stability and moorings for offshore rigs.

Wire rope has long been a standard component for the transportation industry, from the cable cars of San Francisco to the lift chairs for ski resorts. For many years, cable cars have relied on heavy duty cables (wire ropes) to be pulled by a central motor from multiple locations. It is a method of transportation that has existed for centuries.

In Europe, funiculars use cables that hang from a support to move cars up and down a mountain with cables moving in opposite directions. The word funicular is from the French word funiculaire, meaning railway by cable. The terms wire rope and cable are used interchangeably when discussed by professionals. The first part of funicular, or funiculaire, is from the Latin word "funis," meaning rope.

The major use for wire ropes in the food and beverage industries is as a means for lifting and moving heavy loads. Wine barrels and containers full of ingredients are lifted and placed through use of cranes and wire ropes. They are also part of conveyor systems that move products from one station to another.

From the beginnings of amusement rides up to the present, wire ropes have been an essential part of attraction construction and safety. They pull cars on roller coasters, hold cabins that swing, and move carriages through haunted houses. The main concern of amusement parks is safety. The strength, stability, and guaranteed performance of wire ropes ensures that people who attend amusement parks will have a good time and stay safe.

The rigging used to complete the stunts in modern movies depends on wire rope for safety. Much like in amusement rides, wire ropes protect performers from injury and harm as they hang above a scene or carry out an impossible move.

The live theater industry uses wire ropes to raise and lower curtains, support overhead rigging, and hold backdrops and scenery pieces. During a production, rapid and efficient movement is a necessity that is facilitated by the use of wire ropes.

Wire rope is a tool that we tend to envision as indestructible, unable to succumb to any form of damage. Though it is exceptionally sturdy and strong as well as capable of enduring constant use, it is just as susceptible to breakdown as any other tool.

To avoid serious harm and damage, wire ropes should be scheduled for regular inspections. There are situations that can damage or break a wire rope; these should be understood prior to the problem arising.

Guide rollers have the potential to damage and cause abrasions on wire rope if they become rough and uneven. Of the various elements of a crane and lift, guide rollers have the greatest contact with the mechanism‘s wire rope. Regular inspection of guide rollers will ensure they are not damaging the rope or causing abrasions.

Bending is normally a regular part of wire rope usage; this occurs repetitively as the rope passes through a sheave. As a wire rope traverses the sheave, it is continually bent and develops cracks or breaks. The cracking and breaking are exacerbated by movement on and off the groove of the drum. Normally, the breakage happens on the surface and is visible. Once it appears, it accelerates to the core of the rope.

A bird cage is caused by a sudden release of tension and a rebound of the rope. This type of break requires that the rope be replaced since the place of the break will not return to its normal condition.

Wire ropes are multi-layered; this makes them flexible and torque balanced. The layering inside and outside creates flexibility and wear resistance. Relative motion between the wires causes wear over time, which leads to internal breakage. The detection of these breaks can be indicated by an electromagnetic inspection that calculates the diameter of the rope.

Kinked wire rope is caused by pulling a loop on a slack line during installation or operation; this causes a distortion in the strands and wires. This is a serious condition that necessitates rope replacement.

Corrosion damage is the most difficult cause of wire rope damage to identify, which makes it the most dangerous. The main reason for corrosion is poor lubrication that can be seen in the pitted surface of the rope.

The types of damage and problems listed here are only a small portion of the problems that can be caused if a wire rope is not regularly lubricated and inspected. Various regulatory agencies require that wire ropes be inspected weekly or monthly and provide a list of factors to examine.

As with any type of heavy duty equipment, wire rope is required to adhere to a set of regulations or standards that monitor and control its use for safety and quality reasons. The two organizations that provide guidelines for wire rope use are the American Society of Mechanical Engineers (ASME) and the Occupational Safety and Health Administration (OSHA).

ASME is a professional association that provides guidelines to promote the engineering profession. OSHA is a government agency whose purpose is to protect workers and ensure their safety.

All wire rope manufacturers and users closely follow the standards and guidelines established by OSHA and ASME. In the majority of cases, they will identify the specific standards they are following in regard to their products.

OSHA‘s regulations regarding wire rope fall under sections 1910, 1915, and 1926, with the majority of the stipulations listed in 1926 under material handling, storage, use, and disposal.

"Running rope in service shall be visually inspected daily, unless a qualified person determines it should be performed more frequently. The visual inspection shall consist of observation of all rope that can reasonably be expected to be in use during the day‘s operations. The inspector should focus on discovering gross damage that may be an immediate hazard."

"The inspection frequency shall be based on such factors as rope life on the particular installation or similar installations, severity of environment, percentage of capacity lifts, frequency rates of operation, and exposure to shock loads. Inspections need not be at equal calendar intervals and should be more frequent as the rope approaches the end of its useful life. Close visual inspection of the entire rope length shall be made to evaluate inspection and removal criteria."

ASTM A1023 covers the requirements for steel wire ropes with specifications for various grades and constructions from ¼ in. (6 mm) to 31/2 in. (89 mm) manufactured from uncoated or metallic coated wire. Included are cord products from 1/32 in. (0.8 mm) to 3/8 in. (10 mm) made from metallic coated wire.

United States Federal Spec RR W 410 covers wire ropes and wire seizing strands but does not include all types, classes, constructions, and sizes of wire rope and strands that are available. The purpose of Spec RR W 410 is to cover more common types, classes, constructions, and sizes suitable for federal government use.

Wire rope and wire seizing strand covered by United States Federal Spec RR W 410 are intended for use in general hauling, hoisting, lifting, transporting, well drilling, in passenger and freight elevators, and for marine mooring, towing, trawling, and similar work, none of which are for use with aircraft.

API 9A lists the minimum standards required for use of wire rope for the petroleum and natural gas industries. The types of applications include tubing lines, rod hanger lines, sand lines, cable-tool drilling and clean out lines, cable tool casing lines, rotary drilling lines, winch lines, horse head pumping unit lines, torpedo lines, mast-raising lines, guideline tensioner lines, riser tensioner lines, and mooring and anchor lines. Well serving wire ropes such as lifting slings and well measuring are also included in API 9A.

Wire rope is a collection of metal strands that have been twisted and wound to form the shape of a helix with the purpose of supporting and lifting heavy loads and performing tasks that are too rigorous for standard wire.

Individual designs of wire rope involve different materials, wire, and strand configurations as a means for supporting and assisting in the completion of a lifting or supportive task.

Wire rope is a complex mechanical device that has many moving parts all working in tandem to help support and move an object or load. In the lifting and rigging industries, wire rope is attached to a crane or hoist and fitted with swivels, shackles or hooks to attach to a load and move it in a controlled matter. It can also be used to lift and lower elevators, or as a means of support for suspension bridges or towers.

Wire rope is a preferred lifting device for many reasons. Its unique design consists of multiple steel wires that form individual strands laid in a helical pattern around a core. This structure provides strength, flexibility, and the ability to handle bending stresses. Different configurations of the material, wire, and strand structure will provide different benefits for the specific lifting application, including:Strength

However, selecting the proper wire rope for your lifting application requires some careful thought. Our goal is to help you understand the components of a wire rope, the construction of wire rope, and the different types of wire rope and what they might be used for. This will allow you to select the best performing and longest-lasting wire rope for the job at hand.

From childhood, many of us have been conditioned to think of a machine as some device with gears, shafts, belts, cams, and assorted whirring parts. Yet, by the rules of physics, an ordinary pry bar is a simple machine, even though it has only one part.

A wire rope is, in reality, a very complicated machine. A typical 6 x 25 rope has 150 wires in its outer strands, all of which move independently and together in a very complicated pattern around the core as the rope bends. Clearances between wires and strands are balanced when a rope is designed so that proper bearing clearances will exist to permit internal movement and adjustment of wires and strands when the rope has to bend. These clearances will vary as bending occurs, but are of the same range as the clearances found in automobile engine bearings.

Understanding and accepting the “machine idea” gives a rope user a greater respect for rope, and enables them to obtain better performance and longer useful life from rope applications. Anyone who uses a rope can use it more efficiently and effectively when they fully understand the machine concept.

Wires are the smallest component of wire rope and they make up the individual strands in the rope. Wires can be made from a variety of metal materials including steel, iron, stainless steel, monel, and bronze. The wires can be manufactured in a variety of grades that relate to the strength, resistance to wear, fatigue resistance, corrosion resistance, and curve of the wire rope.

Strands of wire rope consist of two or more wires arranged and twisted in a specific arrangement. The individual strands are then laid in a helical pattern around the core of the rope.

The core of a wire rope runs through the center of the rope and supports the strands and helps to maintain their relative position under loading and bending stresses. Cores can be made from a number of different materials including natural or synthetic fibers and steel.

Lubrication is applied during the manufacturing process and penetrates all the way to the core. Wire rope lubrication has two primary benefits:Reduces friction as the individual wires and strands move over each other

The number of layers of wires, the number of wires per layer, and the size of the wires per layer all affect the strand pattern type. Wire rope can be constructed using one of the following patterns, or can be constructed using two or more of the patterns below.Single Layer – The most common example is a 7 wire strand with a single-wire center and six wires of the same diameter around it.

Filler Wire – Two layers of uniform-size wire around a center with the inner layer having half the number of wires as the outer layer. Small filler wires, equal to the number in the inner layer, are laid in valleys of the inner wire.

Seale – Two layers of wires around a center with the same number of wires in each layer. All wires in each layer are the same diameter. The large outer wires rest in the valleys between the smaller inner wires.

Warrington – Two layers of wires around a center with one diameter of wire in the inner layer, and two diameters of wire alternating large and small in the outer later. The larger outer-layer wires rest in the valleys, and the smaller ones on the crowns of the inner layer.

On a preformed wire rope, the strands and wires are formed during the manufacturing process to the helical shape that they will take in a finished wire rope.

Preformed rope can be advantageous in certain applications where it needs to spool more uniformly on a drum, needs greater flexibility, or requires more fatigue-resistance when bending.

Direction and type of lay refer to the way the wires are laid to form a strand (either right or left) and how the strands are laid around the core (regular lay, lang lay, or alternate lay).Regular Lay – The wires line up with the axis of the rope. The direction of the wire lay in the strand is opposite to the direction of the strand lay. Regular lay ropes are more resistant to crushing forces, are more naturally rotation-resistant, and also spool better in a drum than lang lay ropes.

Lang Lay– The wires form an angle with the axis of the rope. The wire lay and strand lay around the core in the same direction. Lang Lay ropes have a greater fatigue-resistance and are more resistant to abrasion.

A fiber core can be made of natural or synthetic polypropylene fibers. Fiber cores offer greater elasticity than a steel core but are more susceptible to crushing and not recommended for high heat environments.

A steel core can be an independent wire rope or an individual strand. Steel cores are best suited for applications where a fiber core may not provide adequate support, or in an operating environment where temperatures could exceed 180° F.

The classifications of wire rope provide the total number of strands, as well as a nominal or exact number of wires in each strand. These are general classifications and may or may not reflect the actual construction of the strands. However, all wire ropes of the same size and wire grade in each classification will have the SAME strength and weight ratings and usually the same pricing.

Besides the general classifications of wire rope, there are other types of wire rope that are special construction and designed for special lifting applications.

Some types of wire rope, especially lang lay wire rope, are more susceptible to rotation when under load. Rotation resistant wire rope is designed to resist twisting, spinning, or rotating and can be used in a single line or multi-part system.

Special care must be taken when handling, unreeling, and installing rotation resistant wire rope. Improper handling or spooling can introduce twist into the rope which can cause uncontrolled rotation.

Compacted strand wire rope is manufactured using strands that have been compacted, reducing the outer diameter of the entire strand, by means of passing through a die or rollers. This process occurs prior to closing of the rope.

This process flattens the surface of the outer wires in the strand, but also increases the density of the strand. This results in a smoother outer surface and increases the strength compared to comparable round wire rope (comparing same diameter and classification), while also helping to extend the surface life due to increased wear resistance.

A swaged wire rope differs from a compacted strand wire rope, in that a swaged wire rope’s diameter is compacted, or reduced, by a rotary swager machine after the wire rope has been closed. A swaged wire rope can be manufactured using round or compacted strands.

The advantages of a swaged wire rope are that they are more resistant to wear, have better crushing resistance, and high strength compared to a round strand wire rope of equal diameter and classification. However, a swaged wire rope may have less bending fatigue resistance.

A plastic coating can be applied to the exterior surface of a wire rope to provide protection against abrasion, wear, and other environmental factors that may cause corrosion. However, because you can’t see the individual strands and wires underneath the plastic coating, they can be difficult to inspect.

Plastic filled wire ropes are impregnated with a matrix of plastic where the internal spaces between the strands and wires are filled. Plastic filling helps to improve bending fatigue by reducing the wear internally and externally. Plastic filled wire ropes are used for demanding lifting applications.

This type of wire rope uses an Independent Wire Rope Core (IWRC) that is either filled with plastic or coated in plastic to reduce internal wear and increase bending fatigue life.

Remember, wire rope is a complex piece of mechanical machinery. There are a number of different specifications and properties that can affect the performance and service life of wire rope. Consider the following when specifying the best type of wire rope for your lifting application:Strength

When you select a piece of rope that is resistant to one property, you will most likely have a trade-off that affects another property. For example, a fiber core rope will be more flexible, but may have less crushing resistance. A rope with larger diameter wires will be more abrasion resistant, but will offer less fatigue resistance.

At Mazzella Companies, we offer all different kinds of wire rope from all of the leading manufacturers. We sell the highest-quality domestic and non-domestic rigging products because product quality and operating safety go hand-in-hand. We have one of the largest and most complete inventories of both domestic and non-domestic rigging and lifting products to suit your lifting needs.

If you’re looking for a standard or custom specified wire rope for your lifting project, contact a Lifting Specialist at a Mazzella Companies location near you.

We stock well over 2,000,000 feet of wire rope in our various locations … ready for immediate delivery! We provide wire rope assemblies, and manufacture bridge cables, crane cables, steel mill cables, and thousands of OEM assemblies.

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.

Figure 1. An offshore lift taking place; this one was successful but the ill-fated southtopside module of the Petronius platform remains at the bottom of the Mexican Gulf.

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).

Operational safety depends not only on your equipment, but also on the awareness, skill and performance of the people who manage and use it. It is often difficult to quantify the cost benefits of training the right people but very easy to count the cost of a disaster.

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 ropes are designed to be extremely strong and durable to safely lift and secure heavy items. Wire ropes are commonly used with overhead lifting and rigging equipment to hoist loads – so when things go wrong, it can be extremely dangerous.

Wire rope hazards have caused hundreds of injuries and even fatalities on construction sites. According toone report, more than 60 people were killed over 15 years due to a wire rope breaking.

When wire rope is handled or stored incorrectly, it can tremendously increase the likelihood of a safety hazard. Some of the most common safety issues with this piece of industrial equipment include broken strands, corrosion, crushed wires, or fatigue that causes the rope to slip, stretch, or snap.

At Elite Sales, we have fulfilled lots of orders forwire ropesto replace broken or damaged equipment. So, take our advice with these tips to reduce wire rope hazards through proper handling.

OSHA requires that all overhead lifting and rigging equipment be carefully inspected before use. Certified crane operators are typically responsible for this task – but all workers interacting with wire ropes should know how to conduct an inspection.

First, the wire rope should be visually inspected to note any of the most common signs of wear and tear. This includes crown or valley breaks in the exterior strands or any kinks in the wire rope.

Any visible rusting, loose wires, kinking, or damaged fitting should be noted immediately. The wire rope should be replaced or repaired before it is used, as even a few broke