T M 5 - 3 8 1 - 3 0 5 - 1c.d.e.f.Crane hooks for excess throat opening ortwisting along with a visual for cracks.Wire rope and reeving for conditionscausing possible removal.Wire rope slings for excessive wear,broken wires, kinking, twisting and me-chanical abuse.All end connections such as hooks, shack-les, turnbuckles, plate clamps, sockets, etc.for excessive wear and distortion.4. An Annual Inspection with a signed reportmust be made for the following:a.b.c.d.Crane hook for cracks.Hoist drum for wear or cracks.Structural members for cracks, corrosionand distortion.For loose structural connections such asbolts, rivets and weldments.Wire Rope InspectionThe following is a fairly comprehensive listing ofcritical inspection factors. It is not, however,presented as a substitute for an experiencedinspector. It is rather a user’s guide to the ac-cepted standards by which ropes must be judged.1. Abrasion: Rope abrades when it movesthrough an abrading medium or over drumsand sheaves. Most standards require that ropeis to be removed if the outer wire wear ex-ceeds 1/3 of the original outer wire diameter.This is not easy to determine and discoveryrelies upon the experience gained by theinspector in measuring wire diameters ofdiscarded ropes.2. Rope stretch: All ropes will stretch whenloads are initially applied. As rope deterio-rates from wear, fatigue, etc. (excludingaccidental damage), continued application ofa load of constant magnitude will producevarying amounts of rope stretch. A “stretch”curve plotted for stretch vs. time (Figure 4-41) displays three discrete phases:a.b.c.Initial stretch, during the early (beginning)period of rope service, caused by the ropeadjustments to operating conditions (con-structional stretch).Following break-in, there is a long period -the greatest part of the rope’s service life -during which a slight increase in stretchtakes place over an extended time. Thisresults from normal wear, fatigue, etc. Onthe plotted curve - stretch vs. time - thisportion would almost be a horizontalstraight line, inclined slightly upward fromits initial level.Thereafter, the stretch begins to increase ata quicker rate. This means that the rope isreaching the point of rapid deterioration; aresult of prolonged subjection to abrasivewear, fatigue, etc. This second upturn ofthe curve is a warning indicating that therope should soon be removed.Figure 4-41. S tretch vs. Time4-45
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
