a 1/2-inch-diameter wire rope. Using the formulaabove, you would solve the problem as follows:SWL = (1/2)^{2}x 8SWL = 2 tonsFigure 1-5.—Correct and incorrect methods of measuringwire rope.places on a six-stranded, and four places on an eight-stranded wire rope.Use the average of the threemeasurements as the diameter of the wire rope.Safe Working LoadThe term safe working load (SWL), as used inreference to wire rope, means the load that you canapply and still obtain the most efficient service and alsoprolong the life of the wire rope. Most manufacturersprovide tables that show the safe working load for theirwire rope under various conditions. In the absence ofthese tables, you may apply the following rule-of-thumb formula to obtain the SWL:SWL (in tons) = D^{2}x 8This particular formula provides an ample marginof safety to account for such variables as the number,size, and location of sheaves and drums on which thewire rope runs and such dynamic stresses as the speed ofoperation and the acceleration and deceleration of theload, all of which can affect the endurance and breakingstrength of the wire rope. Remember this formula is ageneral computation, and you should also consider theoverall condition of the wire rope.In the above formula, D represents the diameter ofthe rope in inches. Suppose you want to find the SWL ofWIRE-ROPE ATTACHMENTSWire rope can be attached to other wire ropes,chains, pad eyes, or equipment by splicing, which ispermanent, or by any of a number of wire-ropeattachments. These include sockets and wire-ropeclips. In general, these attachments permit the wire ropeto be used with greater flexibility than would bepossible with a more permanent splice. Theattachments allow the same wire rope to be made up in avariety of different arrangements.ClipsA temporary eye splice may be put in wire rope byusing clips. A single clip (fig. 1-6) consists of threeparts: U-bolt, saddle, and nuts. The correct andincorrect methods of applying these clips to wire ropeare shown in figure 1-6; the second incorrect methodshown is the most common. Notice that the correct wayis to apply the clips so that the U-bolts bear against thebitter end; that is, the short end of the wire rope. If theclips are attached incorrectly, the result will bedistortion or mashed spots on the live end of the wirerope. After a wire rope is under strain, tighten the clipsagain. On operating wire ropes, tighten the clips dailyand inspect the wire ropes carefully at points whereFigure 1-6.—Use of wire-rope clips.1-7