overhead crane wire rope inspection made in china

Wire ropes undergo constant stress and wear through daily use. So, wire rope requires monthly inspection in accordance with this section to reduce the risk of failure and potential resulting injury or property damage. In addition, this section covers criteria to use in determining when to replace rope, and requires inspection of rope on equipment that has been idle for a month or more, before the rope and equipment can be returned to service.

A thorough inspection of all ropes shall be made at least once a month and a certification record which included the date of inspection, the signature of the person who performed the inspection and an identifier for the ropes which were inspected shall be kept on file where readily available to appointed personnel. Any deterioration, resulting in appreciable loss of original strength, shall be carefully observed and determination made as to whether further use of the rope would constitute a safety hazard. Some of the conditions that could result in an appreciable loss of strength are the following:

All rope which has been idle for a period of a month or more due to shutdown or storage of a crane on which it is installed shall be given a thorough inspection before it is used. This inspection shall be for all types of deterioration and shall be performed by an appointed person whose approval shall be required for further use of the rope. A certification record shall be available for inspection which includes the date of inspection, the signature of the person who performed the inspection and an identifier for the rope which was inspected.

Wear and damage to wire rope can’t always be seen on the surface. Konecranes RopeQ Magnetic Rope Inspection pairs visual inspection with non-destructive testing to detect internal broken wires that may escape detection through traditional inspection methods.

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.

If the qualified person determines that, though not presently a safety hazard, the deficiency needs to be monitored, the employer must ensure that the deficiency is checked in the monthly inspections.

All documents produced under this section must be available, during the applicable document retention period, to all persons who conduct inspections under this section.

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Overhead cranes, new or old installed, must be tested and certificated qualified, and get the acceptance inspection, before being put into work. Crane inspection and crane testing are necessary and important for crane commissioning and crane acceptance, which is indispensable procedure to check the overhead crane manufacturing and installation quality, and guarantee crane safety during operation.

Besides crane commissioning and acceptance inspection, the regular overhead crane inspection and loading test are required each and every year. However, in the following, the crane test and crane inspection for overhead crane commission and acceptance will be put in length.

For a newly installed overhead crane or overhauled crane, before commissioning, we should organize experienced electrician, fitter, crane operators and relevant technical personnel to check the overhead crane comprehensively. The crane inspection main contents are as follows:

3) Overhead crane brake should be accurate and reliable. Two brakes should be consistent with each other, which are installed for the running mechanism of overhead crane.

After inspection and preparation, the overhead crane operation test can proceed. The running test of overhead crane can be divided into the following three steps:　no－load test, static load test, and movement test.

Overhead crane no-load test are mainly divided into the three parts, the crane trolley travelling test, overhead crane travel test, and no-load hook test.

Hanging a plumb in middle of crane girder to examine the original bending degree. Operating trolley/hoist come to middle of girder, lifting loads 1.25times of rated capacity, up to 100mm, and keep this condition 10min on both sides of girder.

Place trolley/hoist stop in middle, lifting rated capacity to test girder’s resilience downwarping, which should not be more than L/700. For single girder overhead crane, the resilience downwarping should be not more than L/600.

CLEVELAND, OH – Mazzella Lifting Technologies, a Mazzella Company, is pleased to announce the acquisition of Denver Wire Rope & Supply. This acquisition will strengthen Mazzella’s footprint west of the Mississippi River and reinforce Mazzella’s commitment to be a one-stop resource for lifting and rigging services and solutions.

Denver Wire Rope & Supply has been in business since 1983 and services a variety of industries out of their location in Denver, CO. Denver Wire Rope & Supply is a leading supplier of rigging products, crane and hoist service, below-the-hook lifting devices, and certified rigging inspection and training. Effective immediately, Denver Wire Rope & Supply will operate as Mazzella / Denver Wire Rope. Terms of the transaction are not being disclosed.

“Denver Wire Rope & Supply will complement the wide range of products and services that Mazzella Companies offers. We are dedicated to being a single-source provider for rigging products, overhead cranes, rigging inspections, and rigging training. Both companies commit to a customer-first mentality, providing the highest-quality products, and leading by example when it comes to safety and sharing our expertise with customers and the market,” says Tony Mazzella, CEO of Mazzella Companies.

“Our team and family are excited to be part of the Mazzella Companies. This acquisition strengthens our place in the market and allows our team to continue to provide excellent service and products to our valued customer base and expand our offering,” says Ken Gubanich, President of Denver Wire Rope & Supply.

“Over the years, we have had numerous companies show interest in purchasing Denver Wire Rope & Supply, none seemed to be the right fit. We are looking forward to becoming a part of an aggressive, passionate, and progressive organization. As a family business for over 36 years, it is important to us that our customers/friends, suppliers, and team members continue to be treated with first-class service, products, and employment opportunities. Again, we are very enthusiastic about our future and look forward to being a quality supplier for your crane, safety training, rigging, and hoisting needs for years to come,” says Gubanich.

“We wish Ed and Carol Gubanich all the best in their retirement. We welcome Ken and the other second and third-generation Gubanich family members, as well as the entire Denver Wire Rope Team, into the Mazzella organization,” says Mazzella.

We’ve changed our name from Denver Wire Rope to Mazzella. Aside from the new name and logo, our member experience is virtually unchanged. Here are some common questions and answers related to this change.

In 2019, Denver Wire Rope & Supply was acquired by Mazzella Companies to expand lifting and rigging products and services to the western half of the United States.

In 1954, James Mazzella founded Mazzella Wire Rope & Sling Co. in Cleveland, OH. For over 65 years, the company has grown organically by nurturing historic relationships, expanding its product offerings, and entering new markets through acquisition.

Today, Mazzella Companies is one of the largest privately held companies in the lifting and rigging industries. Since our humble beginnings, we’ve grown to over 800 employees with over 30 locations across North America. Our product offerings have expanded from basic rigging products, to include:Overhead crane fabrication

Wire ropes are widely employed components in diverse areas, such as in industrial production, tourist cable cars, mining, metallurgy, shipbuilding, and elevators. Wire rope is a heavily loaded component, and long-term continuous operation eventually result in corrosion, wear, broken wires, loose wires, and fatigue, which decrease the loading strength of the rope, and can cause accidents, resulting in property damage and injury [1]. The traditional damage detection method is artificial visual inspection, which is a low efficiency, time-consuming, and unreliable method [1]. The development of a fast, non-destructive, and automatic detection technology is therefore necessary.

Wire rope defects include three main types: the loss of metallic area (LMA), local faults (FLs), and structural faults (SFs). The main non-destructive testing (NDT) methods employed for wire rope inspection include electromagnetic detection, ultrasonic guided wave (UGW) evaluation, radiation testing, eddy current inspection, and optical detection [1]. However, designing a precise detection device that can quantitatively determine the characteristics of defects, such as the number of broken wires, remains problematic, particularly when operating in severe environments [2].

The UGW method has been shown to provide a detection speed that is faster than other methods, but the method demonstrates a low anti-interference ability and suffers from strong background noise [3,4,5,6,7]. Treyssède and Laguerre’s [3] applied the transmission characteristics of UGW for wire rope testing. The researchers developed a semi-analytical finite element method, and calculated the optimal excitation and receiving sites. This approach provided a wave dispersion curve for spiral steel rope. Vanniamparambil [4] proposed a novel detection method that combined three technologies: UGW, acoustic emission techniques, and digital image processing. Xu [7] evaluated the detection precision of the UGW method for wire rope defects obtained at different frequencies, showing that wire ropes at higher frequencies had longer recovery lengths for their elastic waves. Raisuitis [5] investigated the propagation of UGWs along composite multi-wire ropes with various types of acoustic contacts between neighboring wires and the plastic core. Tse and Rostami [6] investigated the efficiency of employing the magnetostriction of ferromagnetic materials in conjunction with the UGW method for wire rope defect inspection, and the location and severity of defects were approximately identified and characterized using the short-time Fourier transform and wavelet analysis. Other detection methods, such as radiation testing [8] and eddy current inspection [9], have not been applied to wire rope inspection to a large extent.

Electromagnetic detection methods are commonly employed for the NDT of wire rope [2]. The basic principle behind wire rope electromagnetic detection is illustrated in Figure 1. The lower permeability of the air leads to magnetic field leakage (MFL) from the rope defect, and the strength of the MFL can be obtained from an appropriately designed magnetic detection device. In terms of the type of excitation source employed, electromagnetic detection can be divided according to the use of a coil [10,11] or a permanent magnet [12,13,14,15,16,17] for generating a magnetic field. Modified main-flux equipment has been developed for wire rope inspection, which induced changes in the electromagnetic field strength owing to the leakage field derived from defects in various large-diameter wire ropes [10]. Other researchers [11] employed a pair of saddle coils for the magnetization of a steel track rope, and this system was applied to detect small, inner flaws in the rope. Permanent magnets have been employed in a saddle structure to saturate wire rope in a uniform magnetic field [14,15,16,17]. Wang et al. [12] investigated the effect of excitation distance and the lift-off distance between the sensors and the wire rope surface on the detection precision. The researchers accordingly modified the magnetic circuit of the detector to restrain the impact of fluctuations in the sensor lift-off distance. Xu et al. [18] developed a magnetic excitation model. Based on this model, the researchers established design criteria for the size of the excitation structure, proposed a theoretical framework for the excitation structure size based on numerical analysis, and adjusted the theoretical design using finite element analysis (FEA).

Obtaining a precise MFL signal is the most important aspect for the accurate electromagnetic NDT of wire rope. For MFL signal acquisition, a commonly employed in-service NDT method utilizes an induction coil [10,17], Hall effect sensor [14,18,19,20,21], giant magnetoresistive (GMR) sensor [11,22], and tunnel magnetoresistive (TMR) sensor [23]. Jomdecha and Prateepasen [10] modified a conventional induction coil into a coil array that densely covered the wire rope to acquire the MFL signal. Wang and Tian [14] utilized FEA to address the problems associated with the weak MFL signals derived from small defects, and they investigated the gathered magnetism of the magnetization rope. They designed a detector with an annular pole polymagnet on one side using Hall elements as inductors. This detection system was able to capture weak MFL signals within the strong magnetic field. Xu and Wang [18] developed an online modular-detector NDT system using a Hall effect sensor that successfully detected inner broken wires. The researchers also presented three filtering algorithms. Detectors based on Hall effect sensor arrays have been widely applied for NDT under strong magnetic field conditions [19,20,21]. Cao [19] created an image from the defect data which was obtained by Hall sensors array, and applied digital image processing to extract and detect defect characteristics. Zhang et al. [20] employed signal processing to suppress the effect of lift-off distance, and applied statistical processing to distinguish different types of defects and to obtain binary image data describing the spatial extent of defects. Zhang et al. [21] applied a space filter to suppress the texture of strand waves after obtaining MFL gray-level images of wire rope defects, and the image spectrum texture was extracted as the characteristic vector used for recognition. GMR sensors have been employed for MFL signal acquisition because of their high sensitivity, high precision, and small size. GMR sensors were placed into a sensor array and densely distributed on the wire rope surface in a manner similar to that employed in a Hall effect sensor application [11]. Zhang and Tan [22] utilized the high sensitivity of a GMR sensor to develop a detection technique based on remanence magnetization, which combined the benefits of a simple structure and high detection speed with high precision. Wu et al. [23] demonstrated that TMR sensors can be applied to detect small discontinuities on a wire rope surface.

MFL signals contain a variety of distinct noise signals, which makes the development of an efficient de-noising algorithm challenging work. Currently, a number of noise reduction algorithms are commonly employed, including wavelet analysis de-noising, low-pass filter, notch filter [21], adaptive filter [20], morphological filter [24], and a de-noising algorithm based on compressed sensing (CS) [22]. Zhang et al. [20] applied digital image processing to develop a space filter for smoothing the defects in an MFL signal image. Zhang et al. [21] proposed a baseline estimation algorithm to suppress the effect of undulations in the lift-off distance and an adaptive notch filtering algorithm to filter the strand wave for increasing the signal-to-noise ratio. Zhang and Tan [22] utilized wavelet multi-resolution analysis to eliminate the baseline of the signal. Their work was based on the CS wavelet de-noising algorithm, and they calculated the best sparse transform expression to completely filter out the noise. Tian et al. combined the wavelet transform and the morphological transform to create a morphological filter algorithm that suppressed the interference associated with the baseline drift in the wire rope signal. Artificial neural networks have been widely applied to realize the quantitative detection of wire rope defects. These networks operate much like back propagation (BP) neural networks employed by a number of researchers [20,21,22]. However, BP neural networks suffer from some limitations and shortcomings, such as poor generalization and slow convergence.

Devices based-on the x-ray method are generally bulky, heavy, and suffer from high maintenance costs, and furthermore, it is difficult to accurately locate defect positions with the UGW detection method, which suffers from external disturbances and limited detection length. The eddy current inspection method is difficult to apply in practice for producing coils on-site, and the system is difficult to manage. However, conventional electromagnetic NDT typically utilizes a large, heavy excitation device as well. Moreover, extracting defect information from the induction coil is difficult, and, in addition, the sensitivity of Hall effect sensors is low. Conventional digital filter algorithms cannot adequately suppress the noise in the MFL signal. This limited ability to reduce noise makes it difficult to separate the defect signal and the strand wave under low signal-to-noise ratio conditions while processing the signal.

To overcome the disadvantages of existing detection devices, we developed a prototype device based on the RMF of a wire rope. This inspection method utilizes GMR sensors for excitation signal acquisition. After magnetizing the wire rope with permanent magnets, the GMR sensor array was utilized to obtain the RMF strength of the rope surface. This detection system is non-contact and non-invasive which prolongs the service life of test equipment. A novel filter algorithm based on the Hilbert-Huang transform (HHT) and compressed sensing wavelet filtering (CSWF) was developed to suppress the various system noises. The HHT was employed to remove the DC component of the signal and balance the sensor channels. CSWF was employed to suppress high-frequency noises and strand waves. Then, we applied digital image processing to create a binary image using a filter based on corrosion and expansion. Subsequently, defects were located and segmented within the gray-level image. Because an 18 GMR sensor array was employed, the resulting gray-level image included only 18 pixels in its circumference. Three spline interpolations were performed to improve the circumferential resolution of the gray-level image. Thirteen image characteristics comprising 6 image textures and seven invariant moments were extracted as defect feature vectors. A radial basis function (RBF) neural network, which is a fast-learning classification network that provides a global optimum, was adopted to quantitatively detect the number of broken wires in the rope. Experimental results demonstrate that, when the absolute limiting error for the detected number of broken wires is 2, the recognition rate is as high as 93.75% with an average recognition error of 0.7813 wires.

History repeats itself; and this is no different when applied to crane maintenance. If you use the same approach towards a typical maintenance procedure you will ultimately achieve the same result. Generally, this is considered a good thing when applied to maintenance because predictability allows for more consistency, thus eliminating unscheduled downtime.

On the other hand, simply performing a routine inspection, time after time without any documentation, prevents the user from obtaining important information that is critical to the overall operating cost of the equipment employed.

When you look at the applicable overhead crane code from country to country you will easily find the criteria for retiring a crane wire rope from service. They clearly outline criteria when to replace wire rope.

The clues are not in the retirement criteria but they can be found during the rope inspection itself. It is these clues that can help the crane user to take a course of action to improve wire rope life and achieve the cost benefits that go along with this improvement.

The best recommendations from wire rope engineers are those where they have had the opportunity to examine the rope in service at or near the end of the rope’s life. They are able to look at the affected area of the wire rope and examine the equipment that is part of the rope path. From this examination, they are usually able to determine the primary cause of rope retirement. They usually fall into one of three categories: rope related, equipment related and/or operator related.

Of course, it is not always possible to have a wire rope engineer examine a rope in every instance. That is the job of the rope inspector. Since it is this person that has the opportunity to examine the rope in all conditions, it would be appropriate for these inspectors to learn what the rope inspection is actually telling them. The best way to accomplish this is to start documenting the inspections in a wire rope inspection log.

The wire rope inspection log becomes a valuable tool because you can see the rope’s history at a glance. By saving these logs for individual ropes, an inspector can look for trends that might require a course of corrective action. As an example, if you keep seeing ropes coming out of service due to corrosion, then you would review the type of lubricant being applied and its frequency of application.

An overhead hoist is basically a wire rope fatigue machine. The rope never touches itself. It simply cycles back and forth through sheaves while it is coming on and off the drum. Hence, ropes are usually retired because of broken wires. This may be simply due to fatigue, however, the inspector should check the type and nature of the broken wires and see if there is a pattern to their location. Unusual wire breaks or patterns should be further investigated as they may be equipment or operator related.

If the problem is equipment related and not picked up at the individual inspection, a review of previous forms may show a downward trend in rope life that might be related to wear on the sheaves and/or hoist drum. This is the type of problem that will have premature damage in the same area rope after rope. It is a good idea to keep previous rope inspection histories so that you can make this comparison. Often, the report is thrown out once the rope is retired from service and valuable information is lost.

If the cause is operator related (a popped rope core due to shock loading, for example), then you have documentation that will enable you to help the operator recognise the problem if it occurs more than once. One of the more common operator problems is from side loading the wire rope on an overhead crane. This is hard on the rope but can also cause the rope to jump a drum groove that could sever or severely damage the rope. This is an operational problem and should be pointed out to employees as being a dangerous practice.

One of the solutions in improving rope life after reviewing the inspection logs may be simply changing the rope construction. With this inspection information in hand you can now consult your wire rope supplier to see if there are any rope constructions that will provide longer rope life. Wire rope catalogues are helpful in making your decision, but not all rope constructions shown in catalogues are necessarily available from stock. This is why it is recommended that you contact your supplier for availability of different rope constructions.

With little or no change in cost, you might be able to select one of many general purpose rope constructions available to increase your operating rope life. Most often, overhead hoists are already fitted with 6x37 classification wire ropes that are best suited for fatigue applications. If your crane is fitted with a 6x19 classification rope, then switching to a 6x37 classification wire rope will increase fatigue life. If your hoist is already fitted with a 6x37 classification rope and you are looking for increased performance (lower operating costs), then your next option would be to consider a high performance wire rope construction.

Examples of these high performance ropes are Dyform-6 and Dyform-8 (shown right). During the outer strand manufacturing process, the wires are drawn through a special Dyforming die that compacts the finished strand and results in a smooth flat surface around its periphery. This compacting process provides the rope with both a greater surface area and increased metallic area. This results in greater wire rope fatigue life due to the lower bearing pressures and stress levels. An added benefit is reduced wear on the crane’s sheaves and drums because of the rope’s increased surface area. It is more evident in the Dyform-8 construction because of the two extra strands in its construction. Dyform-8 is also available with a plastic covered core which enhances its fatigue life and should be considered for the most severe crane applications.

An American steel company located in the Midwest found itself experiencing short rope life on its anti-sway block P&H crane. The rope originally specified for the crane was a 6x37 IWRC wire rope. This general purpose wire rope lasted only four to five weeks under normal usage. The rope was removed from service after meeting the broken wire retirement criteria as outlined in the ASME B30.2 code. Because it kept good wire rope inspection records, the company realised that it needed to start looking for a better performance wire rope construction. After experimenting with (and documenting) different rope constructions, the company finally settled on Dyform-8. This construction achieved 13 months of continuous service, a more than elevenfold increase in performance over the original rope construction.

Dyform-6 and Dyform-8 are just two of many high performance rope constructions available on the market today. Though costing more than general purpose ropes, their increased operating life usually exceeds their premium. Again, consultation with the rope supplier is essential in making the correct selection to suit your particular application and design factors.

It must be pointed out that the condition of a crane’s sheaves and/or drum may be causing less than desired wire rope life. There will be no improvement in rope life by putting a high performance wire rope in a worn, undersize sheave. Check the sheave and drum groove profiles before any new wire rope is installed.

Also, if you feel that you are not receiving adequate performance from your current wire ropes, there is an important point to check before opting for high performance wire ropes. Are you receiving the ropes that you think you are getting? To make sure that you are obtaining the wire rope you ordered, request a copy of the actual wire rope manufacturer’s test certificate. Performance can vary from manufacturer to manufacturer which further illustrates the importance of keeping good records that also give you the opportunity to compare brands.

Wire rope is a large part of the crane’s operating cost over its lifetime and this is reflected in the Crane Manufacturers Association of America (CMAA) specification 70 – ‘Specifications for top running bridge & gantry type multiple girder electric overhead travelling cranes’ – where higher duty cranes use larger drum and sheave diameters which provide for better rope life. The chart (next page) lists these classes along with their guide for the type of rope construction and minimum bending ratio requirements.

When considering the purchase of a new crane, the user can review these classes and select the most economical crane based on their requirements. Obviously, the smaller the sheave and drum diameters, the less expensive the crane. However, wire rope life (measured in cycles) will be adversely affected. Additionally, other crane components may not be suitable for high duty-cycle operation. Therefore, it is extremely important to work with the crane manufacturer to select the right class for the right application.

As mentioned earlier, there are many wire rope constructions on the market. As a sensible approach to designing or looking at new unproven overhead hoisting systems, it is best to select ropes conservatively like the general purpose ropes as outlined in the CMAA table. This will allow the user to employ high performance wire ropes like Dyform-6 and Dyform-8 if the application needs it. If a crane designer selects the ultimate rope for a new and untried system, if rope life proves to be less than desirable the crane user may not have the option to change to a high performance rope alternative. This could lead to higher than expected maintenance costs. If the crane is fitted with high performance ropes from the factory, it is advisable to verify the crane’s performance with the crane manufacturer.

The message for crane manufacturers is: it is fine to use these high performance ropes on new systems, but they should be tested for wire rope reliability before being released to consumers.

The first step to evaluating rope performance is history. Wire rope always tells its story through proper examination and the rope inspector will soon find that keeping good rope records will allow one to see what type of problems are being experienced; or what gains can be realised by changing rope constructions or manufacturers. These well documented inspections will tell inspectors what they need to know. By examining the past, you can improve your future. John Manka is a wire rope consultant with 24 years experience in the industry

Rope diameter is specified by the user and is generally given in the equipment manufacturer’s instruction manual accompanying the machine on which the rope is to be used.

Rope diameters are determined by measuring the circle that just touches the extreme outer limits of the strands— that is, the greatest dimension that can be measured with a pair of parallel-jawed calipers or machinist’s caliper square. A mistake could be made by measuring the smaller dimension.

The right way to unreel.To unreel wire rope from a heavy reel, place a shaft through the center and jack up the reel far enough to clear the floor and revolve easily. One person holds the end of the rope and walks a straight line away from the reel, taking the wire rope off the top of the reel. A second person regulates the speed of the turning reel by holding a wood block against the flange as a brake, taking care to keep slack from developing on the reel, as this can easily cause a kink in the rope. Lightweight reels can be properly unreeled using a vertical shaft; the same care should be taken to keep the rope taut.

The wrong way to unreel.If a reel of wire rope is laid on its flange with its axis vertical to the floor and the rope unreeled by throwing off the turns, spirals will occur and kinks are likely to form in the rope. Wire rope always should be handled in a way that neither twists nor unlays it. If handled in a careless manner, reverse bends and kinks can easily occur.

The right way to uncoil.There is only one correct way to uncoil wire rope. One person must hold the end of the rope while a second person rolls the coil along the floor, backing away. The rope is allowed to uncoil naturally with the lay, without spiraling or twisting. Always uncoil wire rope as shown.

The wrong way to uncoil.If a coil of wire rope is laid flat on the floor and uncoiled by pulling it straight off, spirals will occur and kinking is likely. Torsions are put into the rope by every loop that is pulled off, and the rope becomes twisted and unmanageable. Also, wire rope cannot be uncoiled like hemp rope. Pulling one end through the middle of the coil will only result in kinking.

Great stress has been placed on the care that should be taken to avoid kinks in wire rope. Kinks are places where the rope has been unintentionally bent to a permanent set. This happens where loops are pulled through by tension on the rope until the diameter of the loop is only a few inches. They also are caused by bending a rope around a sheave having too severe a radius. Wires in the strands at the kink are permanently damagedand will not give normal service, even after apparent “re-straightening.”

When wire rope is wound onto a sheave or drum, it should bend in the manner in which it was originally wound. This will avoid causing a reverse bend in the rope. Always wind wire rope from the top of the one reel onto the top of the other.Also acceptable, but less so, is re-reeling from the bottom of one reel to the bottom of another. Re-reeling also may be done with reels having their shafts vertical, but extreme care must be taken to ensure that the rope always remains taut. It should never be allowed to drop below the lower flange of the reel. A reel resting on the floor with its axis horizontal may also be rolled along the floor to unreel the rope.

Wire rope should be attached at the correct location on a flat or smooth-faced drum, so that the rope will spool evenly, with the turns lying snugly against each other in even layers. If wire rope is wound on a smooth-face drum in the wrong direction, the turns in the first layer of rope will tend to spread apart on the drum. This results in the second layer of rope wedging between the open coils, crushing and flattening the rope as successive layers are spooled.

A simple method of determining how a wire rope should be started on a drum. The observer stands behind the drum, with the rope coming towards him. Using the right hand for right-lay wire rope, and the left hand for left lay wire rope, the clenched fist denotes the drum, the extended index finger the oncoming rope.

Clips are usually spaced about six wire rope diameters apart to give adequate holding power. They should be tightened before the rope is placed under tension. After the load is placed on the rope, tighten the clips again to take care of any lessening in rope diameter caused by tension of the load. A wire rope thimble should be used in the eye of the loop to prevent kinking.

U-bolt Clips.There is only one correct method for attaching U-bolt clips to wire rope ends, as shown in TheRightWayimage below. The base of the clip bears on the live end of the rope; the “U” of the bolt bears on the dead end.

Compare this with the incorrect methods. Five of the six clips shown are incorrectly attached—only the center clip in the top view is correct. When the “U” of the clip bears on the live end of the rope, there is a possibility of the rope being cut or kinked, with subsequent failure.

Proper seizing and cutting operations are not difficult to perform, and they ensure that the wire rope will meet the user’s performance expectations. Proper seizings must be applied on both sides of the place where the cut is to be made. In a wire rope, carelessly or inadequately seized ends may become distorted and flattened, and the strands may loosen. Subsequently, when the rope is operated, there may be an uneven distribution of loads to the strands; a condition that will significantly shorten the life of the rope.

Either of the following seizing methods is acceptable. Method No. 1 is usually used on wire ropes over one inch in diameter. Method No. 2 applies to ropes one inch and under.

Method No. 1: Place one end of the seizing wire in the valley between two strands. Then turn its long end at right angles to the rope and closely and tightly wind the wire back over itself and the rope until the proper length of seizing has been applied. Twist the two ends of the wire together, and by alternately pulling and twisting, draw the seizing tight.

The Seizing Wire. The seizing wire should be soft or annealed wire or strand. Seizing wire diameter and the length of the seize will depend on the diameter of the wire rope. The length of the seizing should never be less than the diameter of the rope being seized.

Proper end seizing while cutting and installing, particularly on rotation-resistant ropes, is critical. Failure to adhere to simple precautionary measures may cause core slippage and loose strands, resulting in serious rope damage. Refer to the table below ("Suggested Seizing Wire Diameters") for established guidelines. If core protrusion occurs beyond the outer strands, or core retraction within the outer strands, cut the rope flush to allow for proper seizing of both the core and outer strands.

The majority of wire rope problems occurring during operation actually begin during installation, when the rope is at its greatest risk of being damaged. Proper installation procedures are vital in the protection and performance of wire rope products.

Until the rope is installed it should be stored on a rack, pallet or reel stand in a dry, well-ventilated storage shed or building. Tightly sealed and unheated structures should be avoided as condensation between rope strands may occur and cause corrosion problems. If site conditions demand outside storage, cover the rope with waterproof material and place the reel or coil on a support platform to keep it from coming directly in contact with the ground.

While lubrication is applied during the manufacturing process, the wire rope must still be protected by additional lubrication once it is installed. Lubricants will dry out over a period of time and corrosion from the elements will occur unless measures are taken to prevent this from happening. When the machine becomes idle for a period of time, apply a protective coating of lubricant to the wire rope. Moisture (dew, rain, and snow) trapped between strands and wires will create corrosion if the rope is unprotected. Also apply lubricant to each layer of wire rope on a drum because moisture trapped between layers will increase the likelihood of corrosion.

Always use the nominal diameter as specified by the equipment manufacturer. Using a smaller diameter rope will cause increased stresses on the rope and the probability of a critical failure is increased if the rated breaking strength does not match that of the specified diameter. Using a larger diameter rope leads to shorter service life as the rope is pinched in the sheave and drum grooves which were originally designed for a smaller diameter rope. Just as using a different diameter rope can create performance problems, so can the use of an excessively undersized or oversized rope.

Measure the wire rope using a parallel-jawed caliper as discussed in Measuring Rope Diameter at the top of this page. If the rope is the wrong size or outside the recommended tolerance, return the rope to the wire rope supplier. It is never recommended nor permitted by federal standards to operate cranes with the incorrect rope diameter. Doing so will affect the safety factor or reduce service life and damage the sheaves and drum. Note that in a grooved drum application, the pitch of the groove may be designed for the rope’s nominal diameter and not the actual diameter as permitted by federal standards.

Wire rope can be permanently damaged by improper unreeling or uncoiling practices. The majority of wire rope performance problems start here.Improper unreeling practices lead to premature rope replacement, hoisting problems and rope failure.

Place the payout reel as far away from the boom tip as is practical, moving away from the crane chassis. Never place the payout reel closer to the crane chassis than the boom point sheave. Doing so may introduce a reverse bend into the rope and cause spooling problems. Follow the guidelines highlighted under Unreeling and Uncoiling and Drum Winding. Take care to determine whether the wire rope will wind over or under the drum before proceeding. If the wire rope supplier secured the end of the rope to the reel by driving a nail through the strands, ask that in the future a U-bolt or other nondestructive tie-down method be used; nails used in this manner damage the rope.

Take extra precaution when installing lang lay, rotation-resistant, flattened strand or compacted ropes. Loss of twist must be avoided to prevent the strands from becoming loosened, causing looped wire problems.

The end of the rope must be securely and evenly attached to the drum anchorage point by the method recommended by the equipment manufacturer. Depending on the crane’s regulatory requirements, at least two to three wraps must remain on the drum as dead wraps when the rope is unwound during normal operations. Locate the dead end rope anchorage point on the drum in relation to the direction of the lay of the rope. Do not use an anchorage point that does not correspond with the rope lay. Mismatching rope lay and anchorage point will cause the wraps to spread apart from each other and allow the rope to cross over on the drum. Very gappy winding will occur resulting in crushing damage in multilayer applications.

Back tension must be continually applied to the payout reel and the crewman installing the rope must proceed at a slow and steady pace whether the drum is smooth or grooved.Regardless of the benefits of a grooved drum, tension must be applied to ensure proper spooling. An improperly installed rope on a grooved drum will wear just as quickly as an improperly installed rope on a smooth drum. If a wire rope is poorly wound and as a result jumps the grooves, it will be crushed and cut under operating load conditions where it crosses the grooves.

Every wrap on the first or foundation layer must be installed very tightly and be without gaps. Careless winding results in poor spooling and will eventually lead to short service life. The following layers of rope must lay in the grooves formed between adjacent turns of the preceding layer of rope. If any type of overwind or cross-winding occurs at this stage of installation and is not corrected immediately, poor spooling and crushing damage will occur.

On a multilayer spooling drum be sure that the last layer remains at least two rope diameters below the drum flange top. Do not use a longer length than is required because the excess wire rope will cause unnecessary crushing and may jump the flange. Loose wraps that occur at any time must be corrected immediately to prevent catastrophic rope failure.

The use of a mallet is acceptable to ensure tight wraps, however a steel-faced mallet should be covered with plastic or rubber to prevent damage to the rope wires and strands.

Rotation-resistant ropes of all constructions require extra care in handling to prevent rope damage during installation. The lay length of a rotation-resistant rope must not be disturbed during the various stages of installation. By introducing twist or torque into the rope, core slippage may occur—the outer strands become shorter in length, the core slips and protrudes from the rope. In this condition the outer strands become over- loaded because the core is no longer taking its designed share of the load. Conversely, when torque is removed from a rotation-resistant rope core slippage can also occur. The outer strands become longer and the inner layers or core become overloaded, reducing service life and causing rope failure.

The plain end of a wire rope must be properly secured. If the entire cross section of the rope is not firmly secured, core slippage may occur, causing the core to pull inside the rope’s end and allowing it to protrude elsewhere, either through the outer strands (popped core) or out the other end of the line. The outer layer of the outside strands may also become overloaded as there is no complete core-to-strand support.

Secure the ends of the rope with either seizing or welding methods as recommended under Seizing Wire Rope. It is imperative that the ends be held together tightly and uniformly throughout the entire installation procedure, including attaching the end through the wedge socket and the drum dead end wedge

When installing a new line, connect the old line to the new line by using a swivel-equipped cable snake or Chinese finger securely attached to the rope ends. The connection between the ropes during change-out must be very strong and prevent torque from the old rope being transferred into the new rope.Welding ropes together or using a cable snake without the benefit of a swivel increases the likelihood of introducing torque into the new rope. A swivel-equipped cable snake is not as easy as welding the ropes, but this procedure can be mastered with a little patience and practice.

TCK.W invented current the world"s most advanced "magnetic memory wire rope AI weak magnetic detection technology" (referred to as: TCK.W technology), and owns all the intellectual property rights of this technology. TCK.W won the 2018 Offshore Technology Conference (USA) OTC Spotlight on New Technology Award

TCK.W technology meets the market requirements of wire rope inspection for the first time and has the exclusive ownership of the technology worldwide.

TCK.W products have been accepted by users in China, the United States, the European Union, Japan, South Korea, Singapore and other countries. Users spread over ports, oil, mining, ships, construction, steel and metallurgy, national defense, cranes, elevators, ropeways, and cable-stayed Bridge and many other fields.

TCK.W will replace and eliminate current inspection technology in the wire rope inspection fields and become globe leader of the company in this field.

Designed for higher breaking strength and better strength to weight ratio, our crane wire rope is made of high-toughness steel wires that have been stretched to their tolerance limit prior to being stranded together to form a rope with optimum spacing between each strand.

Even if wire strands are tightly twisted, there still be spaces in places where the strand touches with each other. To improve the fill factor of the wire rope, we have added irregularly-shaped wire strand to the rope and sent it through rotary swaging process. Steel wires that are laid in a parallel pattern increase the cross section of the rope. Safety

Special-purpose steel rope is commonly seen in various engineering projects. Via precision design and rigorous test, the rope usually can meet very high safety standards. A large number of wires are arranged in a parallel pattern to form a strand. Various strands then are twisted to produce the steel rope. Such a rope-making method ensures an improved safety performance of the rope Rotation

Our rotation-resistant wire rope contains several strands laid helically around an independent rope core. The lay direction of outer strands is opposite to that of the independent core so that the overall rope can be non-rotating. This series of rope mainly functions as a lifting tool in the crane. It also can be used in a rope take-up system that requires many times of rope winding. Bending Fatigue

Increasing the number of strands within a rope and wires in a strand can lead to an extended contact between the rope and the sheave groove or grooved cable drum, thereby reducing the stress acted on average rope. Through adding irregularly-shaped strand to the wire as well as rotary

Unirope LTD. is an ISO 9001 and LEEA-Lifting Equipment Engineers Association certified company, specializing in the manufacturing, distribution, testing, certification and inspection of Lifting- and Rigging Products. Unirope is servicing the industry since 1956.

In Germany we manufacture High Performance PYTHON® Wire Rope which we stock in a wide variety of constructions for Tower Cranes, Mobile and Truck Cranes, Overhead Cranes, Gantry Cranes in Construction, Automotive and the Steel Industry. We also stock a large variety of standard and custom designed ropes meeting national and international standards.

The SLINGMAX® product line includes TWIN PATH® Slings made from high strength K-SPEC® fibres, super flexible GATOR FLEX® and TRI-FLEX® wire rope slings, and much more. We also provide a complete range of wire rope fittings, rigging hardware, magnets, clamps, hoists, synthetic ropes, and all types of lifting slings. Find Out More ›