Wire Rope Safe Working Load

Characteristics of Wire Rope

Kinks

Equipment Operator Basic - Beginning construction equipment operators manual
Page Navigation
339

Figure 13-7.-Correct and incorrect methods of measuring wire rope. at least 5 feet apart. Use the average of the three measurements as the diameter of the rope. NOTE: A crescent wrench can be used as an expedient means to measure wire rope. WIRE ROPE SAFE WORKING LOAD The term safe working load (SWL) of wire rope means the load that can be applied and still obtain the most efficient service and also prolong the life of the rope. The formula for computing the SWL of a wire rope is the diameter of the rope squared, multiplied by 8 (D x D x 8 = SWL in tons). Example: The wire rope is 1/2 inch in diameter. Compute the SWL for the rope. The first step is to convert the 1/2 into decimal number by dividing the bottom number of the fraction into the top number of the fraction: ( 1 divided by 2 = .5). Next, compute the SWL formula: (.5 x .5 x 8 = 2 tons). The SWL of the 1/2-inch wire rope is 2 tons. NOTE: Do NOT downgrade the SWL of wire rope due to being old, worn, or in poor condition. Wire rope in these conditions should be cut up and discarded. WIRE ROPE FAILURE Some of the common causes of wire rope failure are the following: l l l l size l Using incorrect size, construction, or grade Dragging over obstacles Lubricating improperly Operating over sheaves and drums of inadequate Overriding or crosr winding on drums . Operating over sheaves and drums with improperly fitted grooves or broken flanges . Jumping off sheaves l Exposing to acid or corrosive liquids or gases . Using an improperly attached fitting . Allowing grit to penetrate between the strands, promoting internal wear . Subjecting to severe or continuing overload l Using an excessive fleet angle HANDLING AND CARE OF WIRE ROPE To render safe, dependable service over a maximum period of time, you should take good care and upkeep that is necessary to keep the wire rope in good condition. Various ways of caring for and handling wire rope are listed below. Coiling and Uncoiling Once a new reel has been opened, it maybe coiled or faked down, like line, The proper direction of coiling is counterclockwise for left lay wire rope and clockwise for right lay wire rope. Because of the general toughness and resilience of wire, it tends now and then to resist being coiled down. When this occurs, it is useless to fight the wire by forcing down the turn because it will only spring up again. But if it is thrown in a back turn, as shown in figure 13-8, it will lie down properly. A wire rope, when faked down, will run right Figure 13-8.—Throwing a back turn. 13-5

Privacy Statement
Press Release
Contact