overhead crane wire rope changing procedure brands
Buying new crane ropes is a detailed and thorough process. While it may be time-consuming, wire rope replacement prioritizes safety for your workers, minimizes downtime on a jobsite, maximizes the lifespan of the crane and avoids the costly and time-consuming process of getting correct rope onsite and respooling your crane.
Sometimes, it can seem like the wire rope buying process is overly complicated. This is done on purpose to avoid as many issues as possible when the new rope is installed. The reason for that is so buyers avoid putting the wrong types of ropes on cranes and unnecessarily increasing the risk of injuries to workers or damage to loads being lifted. The processes are to make sure to prevent that added risk and put the correct rope on the correct machine, per Original Equipment Manufacturer (OEM) specifications.
Wire rope specialists ask these questions to understand your circumstances and what your needs are. With this information, they are better prepared to get the absolute correct rope.
Most of the time, the customer should have access to their crane’s operations manual that will show what rope diameter and length is specified. The customer may have to measure or come up with his own calculations on length. The crane manufacturer is going to make a specific drum for that specific type of wire rope.
The rope has to be specific to the lagging of the drum for that machine, which is why there are multiple variations for each size of wire rope because each kind is specific to the type of crane, and it shouldn’t be substituted. Mazzella will only install the rope that is the correct brand and tolerance on a particular crane.
Ordering the correct crane rope will prevent crane rope damage. The wrong rope could cause damage to the equipment, and at worst, boom failure. On the less severe side, you will have bad performance or it might not work at all. You could have twist and/or spooling issues. That could lead to the crane failing altogether, which creates downtime as you wait for the correct wire rope to be ordered/delivered and installed.
Many crane owners are working for somebody else when they’re doing jobs, so if the rope doesn’t work, they’re paying for work that is not getting done and falling behind schedule.
On the more severe side, you could total your crane and/or irreparably damage the load being lifted if you use the wrong wire rope. In the worst-case scenario, using the incorrect rope could result in severe injury and/or the loss of life.
Sometimes, customers assume that there’s a one-size-fits-all replacement, that if it’s a non-rotating rope, it should work on every application. There’s a lot of misinformation on what will work and what won’t work. With our experience and access to all brands of wire rope, Mazzella guarantees we can get you the right rope for your cranes. If Mazzella isn’t comfortable with the project, we won’t supply the wire rope.
If the wrong wire rope is ordered and delivered, it could be hours or days before the correct rope is on location. Especially with a lot of the larger cranes, manufacturers are shipping model-specific ropes all over the country, and depending on location and money, that could cause delays on your jobsite.
With our large inventory of rope, Mazzella can have a new spool of wire on a truck and out for delivery in a matter of hours. Avoid the pitfalls of ordering the wrong crane rope and you’ll have a new spool of wire rope on its way. Once the order process is done, what can your company do to prepare for delivery and installation?
It is a good idea to give management the proper notice of when the installer will be on-site, have the necessary technicians on-site to help the installer with the rope replacement and make sure the installer/technicians have a clear working space.
There’s a lot of downtime associated with making a mistake in the preparation process, so the more prepared you can be for the install, the better. You don’t want a situation where your crane is inactive because of an oversight or completely avoidable situation.
Also, Mazzella recommends you measure your sheaves with a sheave gauge. A sheave gauge will help you measure the wear of the root, the amount of wear on the groove wall and the diameter of the wire rope.
After ordering the correct rope and having the requisite space and approval for installation, how long will it take to remove and replace the old rope when the technician, assistants and supplies arrive onsite? For some small cranes, the timeframe could be as little as 45 minutes, but for larger cranes, removing the old rope and installing the new one could be a several-hour process.
There’s a lot of factors that go into a successful crane rope installation. The most important thing is the quicker your supplier responds to your order and gets a rope on location, the quicker that rope gets installed properly, saving time and money. Downtime is the key, and it could cost companies tens of thousands of dollars per day if their crane(s) are inoperable.
Once a new crane rope is installed, a break-in period or tension period is recommended to make sure everything is performing correctly, and help you avoid shock-loading the newly installed wire rope. The break-in period is recommended because installation and spooling equipment are not going to put adequate tension on the rope. A break-in period consists of putting a low percentage of the working load limit weight on the rope for several lift cycles, and running the blocks up to the boom length (working height) and back down. For the most specific guidelines on the breaking-in process for your new wire rope, refer to the manufacturer’s recommendations.
If a brand-new wire rope on a crane is not broken in properly before lifting a large load, it potentially could damage the rope and render useless the equipment that was just installed on your machine.
When Mazzella fulfills a crane ropes order, it is not just about the sale and the bottom line. While we’re in the business of selling crane ropes, we’re also in the business of building relationships and trust. We are committed to making sure you get the correct products for the right applications.
Crane rope issues don’t just happen 9-to-5 during the normal work week. They happen Friday nights, holidays, weekends and early mornings. They’re always on the clock, and it is just about being honest with the customer and letting them know, they type of rope that is required. That honesty and trust is of utmost importance for the safety of your workers and the proper maintenance of your cranes.
Mazzella has one of the largest crane ropes inventories in the United States. The company provides wire rope assemblies and manufactures bridge cables, crane cables, steel mill cables and thousands of OEM assemblies in sizes from ¼ to 3-inch diameter and 9 to 52 millimeter diameter, domestic and non-domestic and in stock and ready for same or next-day shipment.
Radically redesigned with never-before-seen features – both inside and out – the S-series will set the standard in lifting for years to come. The newly designed structure includes next-generation features such as off-set reeving, stepless hoisting movement and synthetic rope. The tilted rope drum enables more direct rope angles to decrease the wear and tear of reeving components. And offset reeving means more balanced wheel loads for less stress on the crane structure.
The evolutionary synthetic rope is durable but light and doesn’t require lubrication. The rope also features a strong, symmetric structure for less rope defects and safer handling. Rope angle measurement allows for the use of Smart Features including Hook Centering, Snag Prevention and Follow Me.
Single girder overhead travelling crane on the rope guide, also known as rope row device, is a relatively simple damage to the attachment. However, many customers do not know how to replace the rope guide. This article briefly introduced the replacement guide rope device approach and process, for your reference.
Single girder overhead travelling crane replacement guide rope device is necessary with matching. Some manufacturers produce can not use the traditional rope guide. Please pay attention to communicate with us when you buy. When replacing the rope guide, should first cut off the power, remove the wire rope. After removing the hexagonal screw of the rope guide, you can take down the rope guide along the wire rope. During this period, it is necessary to pay attention to the wire rope into the rope groove before installing the rope guide, so that the wire rope does not enter the groove, there may again crush the rope guide.
First remove the fixed screws fixed in the rope guide; open the rope guide, the block in the rope guide on the side facing outward, the rope guide into the; wire rope head into the rope guide, adjust the rope guide, straighten out the winding order of the wire rope; wire rope head into the fixed pile, wedge it with iron wedge; fixed rope guide, install all the fixed screws of the rope guide; start, adjust the rope guide. This is to ensure that the upper and lower rope guide can accurately cut off the fire source, do not let the wire rope relax the good position; single girder overhead crane guide rope device device is simple, the device is strong.
Your crane"s wire rope works hard. (Almost as hard as you do.) It can deteriorate more quickly than you might think, posing a real danger for you and your crew. In this article, we"ll answer the following questions.
Before we get into that, let"s take a brief moment to go over the proper wire terminology. Understanding the make-up of the wire rope allows you to have a clear understanding of when the rope needs to be replaced.
Flexible steel wire rope is made up of individual wires that make up a strand; these strands are then wrapped around a central core to make up a rope.
Understanding the difference between a wire and a strand is critical. If a strand (grouping of wires) in the rope breaks, the crane wire would need to be replaced. However, if a single wire in the strand breaks, the rope itself may still be usable.
Rag & Visual Inspections: In this method, you use a rag in your inspection, pulling it slowly across the strand, stopping for a closer and more detailed inspection wherever the rag gets caught on a wire.
The Diameter Measurement Method: This method involves comparing the diameter of your rope at various intervals with the rope"s official diameter per the manufacturer"s guidelines. A variation in the rope"s diameter can alert you to potential interior damage that a visual inspection would miss.
Localized Flaw Inspections (LF) vs. Loss of Metallic Area Inspections (LMA) - Both methods use electromagnetics to search for a wire rope"s internal damage.
According to OSHA"s safety regulations, you"re required to inspect your crane"s wire ropes at least every 12 months by qualified professionals. However, OSHA and other experts also recommend inspecting your wire ropes more frequently, such as after every initial installation or repair, or daily before each shift to ensure a safe work environment.
As discussed at the very beginning of this article, we can break down wire rope into three parts. First, wires, which make up strands, and then the strands wrapped around the central core make the rope. Of your total number of wires, you never want more than 10% to be damaged before you need to look into crane wire rope replacement.
According to OSHA, only "trained personnel should carry out inspections," and according to the Crane Manufacturers Association of America, a certified crane inspector should get 2,000+ hours of field experience and training.
We at Americrane & Hoist Corporation are just the experts you need, qualified to offer OSHA inspections and provide operator safety training classes to your employees. Contact us today!
In this Crane Rope Products brochure, you’ll find valuable product information and specifications to help you choose the right rope for your application.
Twisted hoist lines can bring a construction project to a sudden halt, resulting in downtime. But the good news is that you can minimize block rotation through proper installation, handling and corrective measures. In this reference document, you will better understand torque and gain tips on how to reduce block rotation.
No single rope can do it all. In this reference document, you will learn how the characteristics of specific ropes should greatly influence your rope choice including: strength, fatigue resistance, crushing resistance, resistance to metal loss and deformation, and resistance to rotation.
In this Product Bulletin, you will learn about the various causes of crushing, the effects of crushing and how to properly evaluate the crushing. Additionally, observations about drum crushing from WireCo WorldGroup engineers are included.
In this product bulletin, you will learn why Category 1 Ropes are special wire ropes that must be handled differently than other wire ropes. Understand why WireCo WorldGroup recommends not removing the welded ends. And, learn the proper step-by-step recommended procedure for cutting and preparing Category 1 Ropes.
In this product bulletin, you will learn WireCo WorldGroup’s preferred technique for installing a hoist rope onto a crane. Learn tips on relieving twist during installation.
In this reference document, you will learn WireCo WorldGroup’s preferred technique for installing rope onto a crane. Additionally, you will learn tips on breaking in your new wire rope, relieving twist, rigging in tight quarters, and cleaning and lubricating ropes.
Despite their durability and strength, wire ropes used on cranes will wear out and need to be retired from service. This reference document will better explain why regular inspection is so crucial to your long-term success.
Learn how to properly install wire rope on mobile cranes. Two factors are key to proper installation no matter what type of equipment, or which wire rope is being used: making sure the rope is free of twist and assuring that the rope is tightly spooled on the drum.
When a load is placed on a rope, torques are created within the rope as wires and strands try to straighten out. Ropes are designed to operate with these load-created torques within them. In this product bulletin, learn four methods of making a lift that is within the capacity of a single-part line. And finally, you will understand the removal criteria of rotation resistant rope.
Using an active, in-line, anti-friction swivel with the majority of types and classes of wire ropes is detrimental to their service life and can lead to unpredictable conditions during operation. This product bulletin provides the basic reasoning behind why swivels aren"t recommended for use with wire ropes except for those that exhibit a similar torque characteristic to that of a category 1 rotation-resistant rope.
XLT4 is designed to be used with a design factor as low as 3.5 on mobile cranes. In this product bulletin, you will learn more about the ASME B30.5 design factor requirements.
XLT4 was designed and engineered to be compatible with a full complement of end terminations including wire rope clips, wedges and swaged crane buttons. In this product bulletin, learn how Union’s 4-strand crane rope delivers more strength than premium 6-strand, and equal or greater stability under load than Category 1 35x7 style rotation-resistance ropes.
XLT4 is truly the four strand mobile crane hoist rope that is unequaled. After reading this product bulletin, you will understand why. You will learn how XLT4 was designed specifically to meet the special wire rope requirements of mobile crane operations and how XLT4 offers a unique combination of characteristics.
More area equals less wear. In this product bulletin, learn why this is important for our XLT4 rope product. After reading this product bulletin, you will understand why XLT4 Crane Rope provides a greater rope footprint when in contact with drums and sheaves and what this means for your application performance. Additionally, you will learn why XLT4 offers less scrubbing and abrasion and why this reduces contact pressure on ropes.
Wire ropes are mechanical devices that consist of moving parts working in sync to support a heavy load and move it to its desired direction. The rigging and lifting industry benefits largely from the utilities of the wire rope. Especially when they are used in overhead lifting equipment such as cranes and hoists. The wire rope is attached firmly to a hoist or crane, and the load is fitted using swivels, hooks, or shackles, facilitating controlled movement. It is used in many applications to support suspension towers or bridges and lower or lift elevators.
Wire ropes have become the preferred lifting device in many industrial applications. It has its fair share of reasons as well. Firstly, the unique design allows flexibility, strength, and the ability to handle bending stresses. Depending on the rope"s material, wire, and strand structure, it will provide different sets of benefits for the specific application it is used in.
Selecting the right wire rope for the right application is a process that involves careful thought. Thoughts involving proper analysis of the above aspects of the wire rope and the particular lifting application is required.
The following factors might prove to be impactful in damaging or breaking a wire rope. Wear and tear on areas that are directly in contact with drums and hoist sheaves.
Lack of proper lubrication and heat exposure leading to corrosion. At temp beyond 120 degrees Celsius, a fibre core wire rope will give way and break.
Improper installations are also a common issue that can cause the wire rope to break. Improper installation kinks create a weak section in the rope, which is exploited with prolonged use.
The coil of rope should be placed on the ground and rolled out straight, ensuring that it does not become contaminated with dust, grit, moisture or other harmful material.
The rope should never be pulled away from a stationary coil as this will induce turn into the rope and form kinks. If the coil is too large to physically handle it may need to be placed on a turntable which will allow the rope to be paid out as the end of the rope is pulled away from the coil.
Where multi-layer coiling is involved the rope should be placed in equipment that has the capability of providing a back tension in the rope as it is being transferred from the supply reel to the drum. This is to ensure that the underlying laps of rope, particularly in the bottom layer, are wound tightly on the drum.
The supply reel should be positioned such that the fleet angle during installation is kept to a minimum. If a loop forms in the rope it should not be allowed to tighten to form a kink.
The reel stand should be mounted so as not to create a reverse bend during reeving, i.e. for a drum with an upper wind rope, take the rope off the top of the supply reel
Otherwise, winding can be performed by hanging the wire drum up in a crane hook, the hook must be lowered max., A sufficient weight (2.5% -5% of the wire MBL) must be hooked, and the steel wire could be wound close to the drum
Steel Wire rope is a very complex machinery element which primary function is the transmission of tensile forces. Its basic constructional design allows repeated changes in the direction of pull through reeving systems incorporating drums and sheaves. General purpose wire ropeshave been developed and standardized in national and international standards . However the increasing demand for higher breaking strength, greater flexibility, better rotation resistance , and extended rope life cannot be met by such general purpose steel wire ropeconstructions. Horizon Cable is a stocking distributor for Python Wire Rope, which through research, development and engineering over many years has developed rope constructions that have significantly improved operating life. There are vast array of applications that Python Wire Rope can be installed by Horizon Cable Service in Oklahoma, Texas, Wyoming, Kansas, North Dakota and New Mexico to improve service life. Below are a few of the proven applications for our high performance wire ropes:
One benefit to High Performance Wire Rope is the increased breaking strength over standard wire ropes. This is achieved in the manufacturing process by compaction processes. Standard ropes are drawn which create a round outer circumference, but compacted ropes have flat outer service. The two types of compaction are STRAND COMPACTION and SWAGE COMPACTION. Strand compaction is the most popular, in this process the compaction is applied to the individual wires, where the swage compaction is applied to the entire wire rope itself. Both have their advantages for particular applications.
Rotation resistant ropes can fall under three different classes Spin Resistant, Rotation Resistant, and Non Rotating. In all of these types of wire ropes the outer layer is twisted opposite for the inner layers. Rotation resistant and spin resistant ropes will have one inner layer, while non-rotating lines will have multiple inner strands rotating a different direction from the outers.
6 strand high strength swage compacted rope that is perfect for applications that require a crush resistant rope to be used in multi-layer winding systems; e.g. boom hoist on lattice boom mobile and tower cranes
Python Compac 18 is recommended for bot multipart load and single part applications where medium rotational stability is needed. Use as main and auxiliary hoist line on Grove, link belt, Manitowoc, Terex and other us made mobile and truck cranes. Also used very successfully as a pulling rope on underground cable pulling winches.
Main and auxiliary hoist line for European type mobile and for all types of construction tower cranes which require a high strength rotation resistant rope construction. Excellent rotation resistant properties make this rope the preferred choice for all single and multiple line reeving systems.
Sometimes, it can seem like the buying process is overly complicated, and Mazzella does that on purpose to avoid as many issues as possible when the new rope is installed.
The reason for that is so our customers avoid putting the wrong types of ropes on cranes and unnecessarily increasing the risk of injuries to workers or damage to loads being lifted. The processes that we go through are to make sure we prevent that added risk and put the correct rope on the correct machine, per Original Equipment Manufacturer (OEM) specifications.
Mazzella wire ropes specialists ask these questions to understand your circumstances and what your needs are. With this information, Mazzella will be better prepared to get the correct rope to match your company’s needs.
Most of the time, the customer should have access to an operations manual in their crane that will show what rope diameter and length is specified for that machine and that configuration. The customer may have to measure or come up with his own calculations on length.
The rope has to be specific to the lagging of the drum for that machine, which is why there are multiple variations for each size of wire rope because each kind is specific to the type of crane, and it shouldn’t be substituted. Mazzella will only install the rope that is the correct brand and tolerance on a particular crane.
On the less severe side, you’re just going to have bad performance, or it might not work at all. You could have twist and/or spooling issues. That could lead to the crane failing altogether, which creates downtime as you wait for the correct wire rope to be ordered/delivered, and then, installed.
Many people who own cranes are working for somebody else when they’re doing jobs, so if the rope doesn’t work, they’re paying for work that is not getting done, and then, falling behind schedule.
Sometimes, customers assume that there’s a one-size-fits-all replacement, that if it’s a non-rotating rope, it should work on every application. There’s a lot of misinformation on what will work and what won’t work.
With our experience and access to all brands of wire rope, Mazzella guarantees we can get you the right rope for your cranes. If Mazzella isn’t comfortable with the project, we won’t supply the wire rope.
If the wrong wire rope is ordered and delivered, it could be hours or days before the correct rope is on location. Especially with a lot of the larger cranes, manufacturers are shipping model-specific ropes all over the country, and depending on location and money, that could add time to the replacement process and cause delays on your worksite.
With our large inventory of rope and commitment to 24-hour service, Mazzella can have a new spool of wire on a truck and out for delivery to you in a matter of hours.
Say you and your company avoid the pitfalls of ordering the wrong crane rope and have a new spool of wire rope on its way. Once the order process is done, what can your company do to prepare for delivery and installation?
There’s a lot of downtime and sitting around waiting associated with making a mistake in the preparation process, so the more prepared you can be for the install, the better. You don’t want a situation where your crane is inactive because of an oversight or completely avoidable situation.
Also, Mazzella recommends you measure your sheaves with a sheave gauge. A sheave gauge will help you measure the wear of the root, the amount of wear on the groove wall and the diameter of the wire rope.
Okay, so after you order the correct rope and have the requisite space and approval for installation, how long will it take to remove and replace the old rope when the technician, assistants, and supplies arrive on-site?
For some small cranes, the timeframe could be as little as 45 minutes, but for larger cranes, removing the old rope and installing the new one could be a several-hour process.The application
There’s a lot of factors that go into a successful crane ropes installation. The most important thing is the quicker your supplier responds to your order and gets a rope on location, the quicker that rope gets installed properly, which saves you time and money.
Once a new crane rope is installed, a break-in period or tension period is recommended to make sure everything is performing correctly, and help you avoid shock-loading the newly installed wire rope.
The break-in period is recommended because installation and spooling equipment are not going to put adequate tension on the rope. A break-in period consists of putting a low percentage of the working load limit weight on the rope for several lift cycles, and running the blocks up to the boom length (working height) and back down.
If a brand-new wire rope on a crane is not broken in properly before lifting a large load, it potentially could damage the rope and render useless the equipment that was just installed on your machine.
While we’re in the business of selling crane ropes, we’re also in the business of building relationships and trust. We’ll always work with and serve you, and are committed to making sure you get the correct products for the right applications.
Crane rope issues don’t happen just 9-to-5, Monday through Friday. They happen Friday nights, holidays, weekends, early mornings. They’re always on the clock, and it’s just about being honest with the customer and letting them know, ‘this is the rope you need.’
We have one of the largest crane ropes inventories in the United States…ready for immediate delivery! We provide wire rope assemblies, and manufacture bridge cables, crane cables, steel mill cables, and thousands of OEM assemblies:In sizes from ¼” to 3” diameter and 9mm to 52mm diameter
We stock a large inventory of high-performance wire ropes available for immediate delivery. We stock our various high-performance ropes at our many locations in sizes from 1/4” to 3” diameter and 9 mm to 52 mm diameter.
Welcome toThe Hoist Guy"s Blog, where our resident Hoist Guy,Andrew T. Litecky, shares his knowledge and experience of many years in theoverhead material handlingindustry.
A customer recently contacted us to reorder the wire rope component of their Electrolifttwin hook monorail hoist. While the hoist was only a year old, they had replaced the wire rope twice within six months. They sent a picture of the damaged rope and asked for reasons why the wire rope was failing.What’s killing my wire rope?
It’s important to note that the wire rope used for hoists and overhead cranes is specially made of extra flexible Improved Plow Steel (IPS). It’s considered superior in durability and tensile strength (bending) to standard, everyday wire rope.
When properly sized and lubricated, a wire rope should last for years, even with frequent use. Wire rope hoists are recommended for heavy duty applications, high frequency usage and where long lifts are needed.
The Answer:Most likely, there’s a problem with how the hoist is operated. Wire rope failure is almost always due to operator error. By design, hoist hook blocks must be raised and lowered straight up and straight down, and the wire rope cable wraps around the drum, within the grooving, in one layer. In the course of picking up a load, if the operator side pulls the rope by more than about three degrees from vertical, the wire rope will jump the drum’s grooves.
Once the grooves are jumped, the operator must realize the error and stop using the hoist immediately. To correct the issue, the load must be lowered and the wire rope must be allowed to return it to the correct drum grooves. If the operator continues to use the hoist with the wire rope piled up at one end of the drum, the rope gets pinched and the cable can become damaged. Also in the course of usage, if the cable goes slack and the wire rope jumps over the drum guard, it could get caught between the drum and the shaft, and the wire rope could fail.
To prevent this problem, we recommend operator training classesand regular inspection of the unit. Every shift should start with an examination of the rope by lowering the hook all the way down. If the rope is damaged, including even one strand broken, stop the process and get the rope replaced. We recommend keeping spare ropes in stock to avoid downtime and
Wire rope forms an important part of many machines and structures. It is comprised of continuous wire strands wound around a central core. There are many kinds of wire rope designed for different applications. Most of them are steel wires made into strands wound with each other. The core can be made of steel, rope or even plastics.
Wire ropes (cables) are identified by several parameters including size, grade of steel used, whether or not it is preformed, by its lay, the number of strands and the number of wires in each strand.
A typical strand and wire designation is 6x19. This denotes a rope made up of six strands with 19 wires in each strand. Different strand sizes and arrangements allow for varying degrees of rope flexibility and resistance to crushing and abrasion. Small wires are better suited to being bent sharply over small sheaves (pulleys). Large outer wires are preferred when the cable will be rubbed or dragged through abrasives.
There are three types of cores. An independent wire rope core (IWRC) is normally a 6x7 wire rope with a 1x7 wire strand core resulting in a 7x7 wire rope. IWRCs have a higher tensile and bending breaking strength than a fiber core rope and a high resistance to crushing and deformation.
A wire strand core (WSC) rope has a single wire strand as its core instead of a multistrand wire rope core. WSC ropes are high strength and are mostly used as static or standing ropes.
Wire ropes also have fiber cores. Fiber core ropes were traditionally made with sisal rope, but may also use plastic materials. The fiber core ropes have less strength than steel core ropes. Fiber core ropes are quite flexible and are used in many overhead crane applications.
The lay of a wire rope is the direction that the wire strands and the strands in the cable twist. There are four common lays: right lay, left lay, regular lay and lang lay. In a right lay rope the strands twist to the right as it winds away from the observer. A left lay twists to the left. A regular lay rope has the wires in the strands twisted in the opposite direction from the strands of the cable. In a lang lay rope, the twist of the strands and the wires in the strands are both twisted the same way. Lang lay ropes are said to have better fatigue resistance due to the flatter exposure of the wires.
Wire ropes are made mostly from high carbon steel for strength, versatility, resilience and availability and for cost consideration. Wire ropes can be uncoated or galvanized. Several grades of steel are used and are described in Table 1.
Steel cable wire is stiff and springy. In nonpreformed rope construction, broken or cut wires will straighten and stick out of the rope as a burr, posing a safety hazard. A preformed cable is made of wires that are shaped so that they lie naturally in their position in the strand, preventing the wires from protruding and potentially causing injury. Preformed wire ropes also have better fatigue resistance than nonpreformed ropes and are ideal for working over small sheaves and around sharp angles.
Lubricating wire ropes is a difficult proposition, regardless of the construction and composition. Ropes with fiber cores are somewhat easier to lubricate than those made exclusively from steel materials. For this reason, it is important to carefully consider the issue of field relubrication when selecting rope for an application.
There are two types of wire rope lubricants, penetrating and coating. Penetrating lubricants contain a petroleum solvent that carries the lubricant into the core of the wire rope then evaporates, leaving behind a heavy lubricating film to protect and lubricate each strand (Figure 2). Coating lubricants penetrate slightly, sealing the outside of the cable from moisture and reducing wear and fretting corrosion from contact with external bodies.
Both types of wire rope lubricants are used. But because most wire ropes fail from the inside, it is important to make sure that the center core receives sufficient lubricant. A combination approach in which a penetrating lubricant is used to saturate the core, followed with a coating to seal and protect the outer surface, is recommended. Wire rope lubricants can be petrolatum, asphaltic, grease, petroleum oils or vegetable oil-based (Figure 3).
Petrolatum compounds, with the proper additives, provide excellent corrosion and water resistance. In addition, petrolatum compounds are translucent, allowing the technician to perform visible inspection. Petrolatum lubricants can drip off at higher temperatures but maintain their consistency well under cold temperature conditions.
Various types of greases are used for wire rope lubrication. These are the coating types that penetrate partially but usually do not saturate the rope core. Common grease thickeners include sodium, lithium, lithium complex and aluminum complex soaps. Greases used for this application generally have a soft semifluid consistency. They coat and achieve partial penetration if applied with pressure lubricators.
Petroleum and vegetable oils penetrate best and are the easiest to apply because proper additive design of these penetrating types gives them excellent wear and corrosion resistance. The fluid property of oil type lubricants helps to wash the rope to remove abrasive external contaminants.
Wire ropes are lubricated during the manufacturing process. If the rope has a fiber core center, the fiber will be lubricated with a mineral oil or petrolatum type lubricant. The core will absorb the lubricant and function as a reservoir for prolonged lubrication while in service.
If the rope has a steel core, the lubricant (both oil and grease type) is pumped in a stream just ahead of the die that twists the wires into a strand. This allows complete coverage of all wires.
After the cable is put into service, relubrication is required due to loss of the original lubricant from loading, bending and stretching of the cable. The fiber core cables dry out over time due to heat from evaporation, and often absorb moisture. Field relubrication is necessary to minimize corrosion, protect and preserve the rope core and wires, and thus extend the service life of the wire rope.
If a cable is dirty or has accumulated layers of hardened lubricant or other contaminants, it must be cleaned with a wire brush and petroleum solvent, compressed air or steam cleaner before relubrication. The wire rope must then be dried and lubricated immediately to prevent rusting. Field lubricants can be applied by spray, brush, dip, drip or pressure boot. Lubricants are best applied at a drum or sheave where the rope strands have a tendency to separate slightly due to bending to facilitate maximum penetration to the core. If a pressure boot application is used, the lubricant is applied to the rope under slight tension in a straight condition. Excessive lubricant application should be avoided to prevent safety hazards.
Some key performance attributes to look for in a wire rope lubricant are wear resistance and corrosion prevention. Some useful performance benchmarks include high four-ball EP test values, such as a weld point (ASTM D2783) of above 350 kg and a load wear index of above 50. For corrosion protection, look for wire rope lubricants with salt spray (ASTM B117) resistance values above 60 hours and humidity cabinet (ASTM D1748) values of more than 60 days. Most manufacturers provide this type of data on product data sheets.
Cable life cycle and performance are influenced by several factors, including type of operation, care and environment. Cables can be damaged by worn sheaves, improper winding and splicing practices, and improper storage. High stress loading, shock loading, jerking heavy loads or rapid acceleration or deceleration (speed of the cable stopping and starting) will accelerate the wear rate.
Corrosion can cause shortened rope life due to metal loss, pitting and stress risers from pitting. If a machine is to be shut down for an extended period, the cables should be removed, cleaned, lubricated and properly stored. In service, corrosion and oxidation are caused by fumes, acids, salt brines, sulfur, gases, salt air, humidity and are accelerated by elevated temperatures. Proper and adequate lubricant application in the field can reduce corrosive attack of the cable.
Abrasive wear occurs on the inside and outside of wire ropes. Individual strands inside the rope move and rub against one another during normal operation, creating internal two-body abrasive wear. The outside of the cable accumulates dirt and contaminants from sheaves and drums. This causes three-body abrasive wear, which erodes the outer wires and strands. Abrasive wear usually reduces rope diameter and can result in core failure and internal wire breakage. Penetrating wire rope lubricants reduce abrasive wear inside the rope and also wash off the external surfaces to remove contaminants and dirt.
Many types of machines and structures use wire ropes, including draglines, cranes, elevators, shovels, drilling rigs, suspension bridges and cable-stayed towers. Each application has specific needs for the type and size of wire rope required. All wire ropes, regardless of the application, will perform at a higher level, last longer and provide greater user benefits when properly maintained.
Lubrication Engineers, Inc. has found through years of field experience, that longer wire rope life can be obtained through the use of penetrating lubricants, either alone or when used in conjunction with a coating lubricant. Practical experience at a South African mine suggests that life cycles may be doubled with this approach. At one mine site, the replacement rate for four 44-mm ropes was extended from an average 18.5 months to 43 months. At another mine, life cycles of four 43-mm x 2073 meter ropes were extended from an average 8 months to 12 months.
In another study involving 5-ton and 10-ton overhead cranes in the United States that used 3/8-inch and 5/8-inch diameter ropes, the average life of the ropes was doubled. The authors attribute this increased performance to the ability of the penetrating lubricant to displace water and contaminants while replacing them with oil, which reduces the wear and corrosion occurring throughout the rope. A good spray with penetrating wire rope lubricant effectively acts as an oil change for wire ropes.
In these examples, the savings in wire rope replacement costs (downtime, labor and capital costs) were substantial and dwarfed the cost of the lubricants. Companies who have realized the importance of proper wire rope lubrication have gained a huge advantage over those who purchase the lowest priced lubricant, or no lubricant at all, while replacing ropes on a much more frequent basis.
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.
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.
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.
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.
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).
All wire rope manufacturers and users closely follow the stan