Part 6. Cutting and Terminating Rope, Attaching Loads, and Dealing with Special Problems
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189 Cutting and Terminating Rope, Attaching Loads, and Dealing with Special Problems Fiber Rope Fiber rope is made of natural or synthetic fibers that are either twisted or braided into yarns and then into rope. A. Cutting There are specific procedures for cutting different kinds of rope. 1. Natural Fiber Twisted natural-fiber rope should be taped with electrician’s friction tape before cutting. This tape is easy to remove and will keep the ends from fraying. Tape about a 2˝ length of rope where the cut is to be made. Use a pair of garden pruning shears to cut the rope in the center of the tape (fig. 6.1). After the rope is cut, remove the tape, and whip the end, using small twine (fig. 6.2). Part 6 6.01 190 Braided natural fiber, such as cotton sash cord, need not be taped for cutting; pruning shears work best for the job. If the rope is to be used for a long time, whipping, dipping the ends in glue, or taping will keep the ends neat. Braided rope is not as susceptible to fraying as twisted rope. 2. Synthetic Fiber Synthetic-fiber rope is best cut with a heated knife designed for the purpose. Live flame can be substituted if the knife is unavailable . Hold the rope in both hands, and rotate it over a flame. Gently pull it apart as you rotate it. The ends can be shaped before they completely cool by pushing them against a hard surface. This method not only cuts the rope but binds the fiber ends together to prevent unraveling (fig. 6.3). Fig. 6.1. Cutting fiber rope Fig. 6.2. Whipping fiber rope 191 B. Knots A knot is used to attach a rope to an object. Knots reduce the breaking strength of rope and can slip or come untied if misapplied . Therefore, the proper knot for a specific application must be used. Knot efficiency is the remaining strength of a rope after a knot has been tied in it. Table 6.1 is a list of the efficiencies of common stage knots. These are average values and will vary depending on a number of conditions. Table 6.1. Knots and Their Efficiencies Knot Type Efficiency (%) Bowline 60 Figure-8 64 Two half hitches around a 15-mm-diameter ring 60 around a 96-mm-diameter post 65 Square knot 43 Clove hitch 75 Clove hitch with two half hitches 65 Eye splice with thimble 95 Fig. 6.3. Cutting nylon rope 192 Fig. 6.4. Bowline Fig. 6.5. Clove hitch with two half hitches Fig. 6.6. Stopper hitch 193 1. Bowline Use this knot (fig. 6.4) when tying a loop in the end of a rope. 2. Clove Hitch This knot is used for tying a rope to a rigid object, such as a batten. When properly tied, it does not slip sideways (fig. 6.5). 3. Stopper Hitch A stopper hitch (fig. 6.6) is used to tie the safety rope on a counterweight hand line (see section 4.11.A.1). 4. Prusik Another knot used to tie a safety line on a counterweight hand line is a prusik. It can also be used to attach a rope sunday to a hand line for use with a block and tackle (fig. 6.7). 5. Half Hitch The half hitch (fig. 6.8) can be used to secure the counterweight safety rope to the lock rail. 6. Figure-8 The figure-8 knot (fig. 6.9) is used at the end of a spot line to hold a length of pipe as a weight (see section 3.08). Fig. 6.7. Prusik knot 194 7. Trucker’s Hitch The trucker’s hitch (fig. 6.10) is used when flying framed scenery with hemp or when tying a batten down to a floor hold. Figure 6.10 shows one of many ways to tie this knot. Wire Rope Cutting, handling, and terminating wire rope all require special care. Carelessness can result in damage and loss of strength to the wire rope. A. Cutting Several different kinds of wire-rope cutters are available on the market. For sizes up through 1 ̸8˝, small hand-held cutters can be Fig. 6.8. Two half hitches Fig. 6.9. Figure-8 knot 6.02 195 used (fig. 6.11). For larger sizes, two hand cutters or a cold chisel must be used (fig. 6.12). never try to...


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