TM5-3810-305-10 The size of the groove is not the only critical item to be examined closely. The condition of the groove is also an important factor of concern. Is it smooth or imprinted? If the groove is imprinted, then it must be re-machined or, if it is imprinted too deeply, it means that sheave, roller or drum must be replaced. If replacement is indicated, a larger sheave or drum should be installed if possible, or a harder material should be specified for the replacement Groove examination should also concern itself with how the groove is wearing. If it is worn off- center, thereby forcing the rope to undercut or to rub against the flange, it then becomes necessary to correct the alignment of the reeving system, and to specify a harder material. When checking the grooves, the bearings of the sheaves and rollers should also be examined. They should turn easily. If not, each bearing must be properly lubricated. “Wobble” in the sheave, from broken or worn bearings, is not acceptable. Bad bearings will set up vibrations in the wire rope that can cause rapid deterioration unless the condition is remedied. Bad bearings also increase the force on the rope that is needed to move a given load, since friction forces will be greatly increased. Sheaves with broken flanges may allow the rope to jump from the sheave and become fouled in the machinery. When this happens, the rope is cut, curled, and the crowns of the wires in the strands are burred. There is ample evidence to support the rule that sheaves with broken flanges must be replaced immediately. A sheave or drum with a flat spot can induce a “whip” into the line. This whip, or wave, travels until it is stopped by the end terminal, at which point the rope may bend severely. This condition helps to accelerate the fatigue breakage of wires. Sometimes the reeving is such that the whip or wave is arrested by a sheave, or the drum itself. In these circumstances, the whipping will cause wire breaks along the crowns of the strands. Obviously, sheaves or drums that excite vibra- tions of this sort must be repaired or replaced. Guideline to Inspections and Reports for Equipment. wire Rope and Wire Rope Slings 1. 2. 3. Maintain all inspection records and reports for the length of time deemed appropriate. Prior to each daily use, the following proce- dure should be followed: a. b. c. d. Check all equipment functions. Lower load blocks and check hooks for deformation or cracks. During lowering procedure and the follow- ing raising cycle, observe the rope and the reeving.  Particular  notice  should  be  paid  to kinking, twisting or other deformities. Drum winding conditions should also be noted. Check wire rope and slings for visual signs of anything that can cause them to be unsafe to use, i.e., broken wires, excessive wear, kinking or twisting, and marked corrosion.  Particular  attention  should  be given to any new damage during operation. Monthly Inspections are recommended with a signed report by an authorized competent in- spector.  The  Monthly  Reports  should  include inspection of the following: a.  All  functional  operation  mechanisms  for excessive wear of components, brake system parts and lubrication. b.  Limit  switches. 4-44