Bureau of safety and environmental enforcement new orleans gulf of mexico ocs regional office january 20. The surrounding strands are thus deprived of support, and the ropes strength and dependability are. A wire rope distributor received a hoist rope and sockets from a rubbertired gantry. Boom hoist wire rope line failure results in fatality high. The analysis of the mechanical tests results of the new rope revealed the fact that the rope had been manufactured in other rope grade.
Pdf failure of an old rope from a stringing lattice transmission towers occurred in winter while the rope was being removed to make way for a new. Some research has been carried out on analysis of wire ropes and the fe approach is also reported by some researchers in the recent past. An examination of the failed boom hoist wire rope revealed that the wire rope had gone without the proper lubrication, which was the responsibility of the insured per the attached lease agreement, bristow remembers. Therefore, there is requirement for a general and accurate strand model which is. The extent of damage to elevator rope failures is often severe and it may sometimes be difficult to distinguish between preexisting damage and damage occurring as a result of the failure.
Pdf failure analysis of crane wire rope azmi rahmat. Failure investigation revealed fatigue cracks initiating at nonmetallic inclusions near the surface of individual wire strands in the rope. Protect your company from wire rope failures by following. Failure analysis, metallurgical services and corrosion testing. Once the test was started, measurements of the rope external temperature were taken using an optical laser pyrometer.
The work of a wire rope detective resembles very much that of sherlock holmes. The proposed rope model gives remarkable results by means of wire by wire analysis scheme. Typical failure modes of wire ropes include fracture, wear, corrosion, geometric failure and thermal failure. A member has reported a serious incident onboard a vessel where the main hoist wire rope of the main crane parted whilst deployed subsea. The distributor hired iti field services to conduct an analysis on the rope and sockets to determine the cause of the failure and to produce written documentation. Comparison of fatigue data for polyester and wire ropes relevant to deepwater moorings stephen j banfield, john f flory, john w s hearle, martin s overington. A wire rope consists of many wires twisted together to make a complex structure combining axial. The actual range of wire rope constructions is wide and varied. A failure analysis of a broken multi strand wire rope from a crane was performed. Fatigue can be a problem with moderate tensile loads and a properly lubricated wire rope with the vgroove drum design. It is possible to calculate, based on feyrers formula, for a set of given parameters rope design, nominal rope diameter, diameter of sheaves, line pull, nominal wire tensile strength and length of most heavily strained rope zone, the. Arcing moltenends 8 cutends 9 mechanicaldamage 1011 scribermarks 12 weldingrelatedwirebreaks hotwelds coldwelds 14 wiredrawing problems. The inclusions were identified as alcati silicates. Metallurgical failure analysis of wire rope cables chemaxx.
The rope is not always to be the only accused parameter. Failure analysis and safety protection of a certain type of wire. Service life prediction of running steel wire ropes. In this work, the corresponding failure mechanisms. A steel wire rope has failed and the accident has caused a lot of damage. The rope was inspected for wire breaks, local damage, wear etc. Our inspector has found 10,000 wire breaks, but the discard number was not reached in any single rope section of a length of 6 x d or 30 x d. The rope user, and maybe also a judge in court, will want to know whether the rope was murdered by external factors or committed suicide e. In extreme cases the rope may be unfit for safe use. Papers and conferences massmin 2012, 6th international conference and exhibition on mass mining. Failure analysis of hoisting steel wire rope sciencedirect.
Key words independent wire rope core, double helical geometry, relative rotation, modeling wire rope. Failure analysis of a drilling wire rope article pdf available in journal of failure analysis and prevention 125 october 2012 with 1,831 reads how we measure reads. Papers and conferences wire rope and rope engineering. Do not downgrade the swl of wire rope because it is old, worn, or in poor condition. Some of the common causes of wire rope failure are the following. We were given the mandate to determine the reasons for the fracture of the wire rope and also to suggest measures to. Pdf a failure analysis of a broken multi strand wire rope from an offshore platform crane was performed. Using incorrect size, construction or grade dragging over obstacles improper lubrication.
Department of labor occupational safety and health administration. Wire rope in these conditions should be cut up and discarded. The results show good agreement with other available results but with a simpler and more practical approach. Wire rope failure location in the lattice boom crawler crane. Analyzing the causes for rope failure or rope fast deterioration must include all parameters which will consider the rope quality, machine parameters, practice of the operators and maintenance team. These wire ropes are moving during the lifting process. Analysis of bending fatigue in a 2inch iwrc wire rope author. Barbara carlsward eastern illinois university school of technology, charleston, illinois. Wire rope forensics wire rope forensics 2 these two authors have pooled their experience in order to create this document.
The fracture of the steel wires in the wire rope showed characteristics of fatigue. These results have indicated that as a wire rope accumulates bending cycles, its strength first decreases because of wear and then increases due to cold working of the wires. Wire ropes, pulleys, counterweights, and connecting systems are used for auto tensioning of contact wires of electric railways. Sheaves and drums sheaves and drums play a very important part in overall rope life. A tree trimmer died when the aerial bucket lift cherry picker he was working from collapsed and fell to the ground. In this case, with the torque wrench manufacturers approval, stainless steel cables were installed. Failure analysis at the kennedy space center victoria l. Overloading a rope also causes its diameter to be reduced. The water depth at the location was approximately 1600m. One rope specimen was cycled on a sheave with tread diameter 1120 mm. Sheaves grooves very seldom if ever wear widerlarger than they were originally machined, wire rope reduced diameter causes sheave grooves to. Examination of failure of fibers from synthetic rope with foreign inclusions using polarized light microscopy dr.
The wire consists of seven strands, one central strand and six strands around it. Pdf failure analysis of failed wire rope researchgate. Continue reading catastrophic failure of vessel main crane wire. A failure analysis of a broken multi strand wire rope from an offshore platform crane was performed. Background a wire rope broke while lifting a load of reinforcing steel estimated to weigh 2. The large size wires were found fractured by cyclic. The stiffness of the rope, k, depends on the length of the rope. Failure to lubricate the rope is another cause of reduced diameter since the fiber core will dry out and eventually collapse or shrink. A short history of wire rope 1 the use of ropes in early civilizations 2 2 ropes in the middle ages 3 3 the albert rope 4 4 strands with a centre wire 8 5 multilayer strands 8 6 the parallel lay strand 9. Wirebreaksandfailureanalysis page preface 1 typesofwirebreaks 2 causesofbreaks 3 preventionofbreaks 4 wirebreakclassification 5 possible sourceofinclusions 6 i process related problems 7 annealing problems. The companion rope was taken for residual break strength testing.
Following a tragic accident during a routine drill procedure, a national accident investigation body approached consultancy experts from the test. Article pdf available in engineering failure analysis 21. Magnetic ndt suggested that the wire hoist ropes, when measured in 2009, still were within a reasonable safety factor, but did not contain any comparable data to a new wire hoist rope. Service life determination of wire hoist ropes using. Eq2 where m is the called the rope modulus change in force for a given stretch, and l is the rope length. Wire rope lubricantpreservative should be applied according to the directions, making sure it has fully penetrated through the cable. Each application has to be considered individually in terms of the degree of degradation allowable. Failure analysis on the wire rope for lifting equipment. Thus, when a rope fractures, mechanical damage can occur as a result of the event. Pdf failure analysis of crane wire rope researchgate.
K schrems and d maclaren 1997 failure analysis of a mine hoist rope, engineering failure analysis, vol. Metallurgical failure analysis of wire rope cable aerial bucket lift. Examination of failure of fibers from synthetic rope with. The test house wire rope failure analysis case study. To maximize rope service life, it is imperative that the equipment have properly maintained sheaves and drum lagging. Wire rope failure in marine tragedy requires failure investigation from consultancy experts. Wire rope theory is based on equilibrium equations which are.
Additionally, potential failures can be predicted, resulting in effective. It has been noted however that these factors may have strong influence on the mechanism of rope failure 1, 2. The bucket is positioned via a combination of booms, hydraulic cylinders and wire rope cables. Certification and marking make sure that the relevant certificate has been obtained before taking the rope into use for a lifting. Technical information 54 warning failure to carry out or pay attention to any of the above could result in a loss of strength andor a reduction in performance. Department of labor occupational safety and health. The failure of a multistrand wire rope used in drilling rig hook is investigated in this case study. The vessel crane was involved in operations in which a 20 tonne clump weight was suspended from the crane main hoist wire. It was noted that the rope was heavily corroded and there was no externally visible lubrication figure 1. However complete failure of a wire rope requires that many wires. A wire rope in one such auto tensioning system suffered premature failure.
On the wire surface were observed decarburised cracks which act as initiation sites for fatigue crack propagation during the application of the wire rope. Boom hoist wire rope line failure results in fatality high island area block a557, platform a ocsg 03484 16 august 2011. The rope and sockets were returned by the customer who believed the rope and sockets failed. Failure of an old rope from a stringing lattice transmission towers occurred in winter while the rope was being removed to make way for a new rope. The report provides an analysis of the results of the first wire rope to be fatigued on this machine. Design modifications to increase fatigue life of fiber ropes. The phenomena of rope evaluation by conducting nondestructive tests by assessing the localized flaws viz. Clara wright national aeronautics and space administration, kennedy space center, fl, 32899 history has shown that failures occur in every engineering endeavor, and what we learn from those failures contributes to the knowledge base to safely complete future missions.
Sheave and drum diameter all wire ropes operating over sheaves and drums are subjected to bending stresses, which eventu. Moreover, the ropes were very far along in the degradation process. The wire rope failed during the raising of the rig and caused some serious damage to the rig. Sheave groove inspection yoakum technical consulting llc 710 brannon field lane houston tx 77041 6 misconceptions on sheave gauging. Very highstrength steel wires had already been existence for more than a hundred years. Analysis with finite element method of wire rope ass. Industrial rope access is the use of specialized rope techniques to place workers in hardtoreach locations to perform onsite failure analysis in hard to reach areas. There are many of published studies on stress analysis, life prediction for wire ropes 17. The precise sequence of events leading to the failure were not known, but the load did not drop because the rope jammed in the gap between sheave and support bracket. This paper presents a study carried out on simple 7 wire single strand rope using the analytical as well as fe approach. I also noted significant broken wires within the rope strands at. The size and number of wires in each strand, as well. Md kuruppu, a tytko and ts golosinski 2000 loss of metallic area in winder ropes subject to external wear, engineering failure analysis, vol.
Short ropes are very stiff, and long ropes are less stiff. New technology for the testing and simulating the performance and service life of wire ropes spin and non spin, installed at. The main reasons for the failure of the wire rope were fatigue and poor inspection. Rope damage after a short time in the hoist system operation of the drilling rigs. Catastrophic failure of vessel main crane wire imca.