- - AGRICULTURE CORE CURRICULUM - - (CLF2000) ADVANCED CORE CLUSTER: AGRICULTURAL MECHANICS (CLF2600) Unit Title: ROPEWORK ________________________________________________________________________ (CLF2602) Topic: ROPE IDENTIFICATION AND CARE Time Year(s) 1 hour 1/2/3/4 ________________________________________________________________________ Topic Objectives: Upon the completion of this lesson, the student will be able to: Learning Outcome #: (M-2) - Identify samples of natural and synthetic fiber ropes. (M-4) - Describe three important practices in rope care. Special Materials and Equipment: Samples of nylon, polypropylene, sisal, manila, cotton, and wire rope; also, samples of misused and defective rope. References: Jurgenson, E. M. (1979). HANDBOOK OF LIVESTOCK EQUIPMENT (2nd ed.). Danville, IL: Interstate Publishers. Phipps, Lloyd J., & Reynolds, Carl L. (1990). MECHANICS IN AGRICULTURE (4th ed.). Danville, IL: Interstate Publishers. Evaluation: Unit Exam TOPIC PRESENTATION: ROPE IDENTIFICATION AND CARE A. Types of Materials Used in Making Ropes 1 Natural Fiber Ropes a. Manila rope is woven from the fibers of the abaca plant, which is native to the Philippines. It is the strongest and most pliable of the natural rope fibers, but it is also the most expensive. Manila rope is susceptible to rot and decay if it becomes wet. b. Sisal rope is lighter in color and has a rougher texture than manila. Sisal is made from the fibers of the agave plant found in Mexico, Central America, East Africa, and the Bahamas. It is not as strong as manila rope, but sisal is more resistant to abrasion. The coarse texture of sisal rope makes it undesirable for use on animals. Most baler twine is made of sisal. c. Cotton rope is the most common natural fiber rope used in the United States. Although it is not as strong as manila and sisal, cotton rope is more desirable in livestock handling due to its softer surface texture. Cotton rope is also susceptible to rot and decay and has a tendency to swell when it gets wet, which decreases its workability. 2. Synthetic Fiber Ropes a. Nylon and dacron ropes are the strongest synthetic ropes available. They are soft, pliable, and less susceptible to rot and mildew than natural fiber ropes. Although these ropes do stretch when wet, they retain their strength under wet conditions. Excessive heat will melt nylon and dacron ropes and long exposure to sunlight will cause the fibers to become brittle and decay. b. Polypropylene and polyethylene ropes have a coarser texture and are less pliable than nylon and dacron. "Poly" rope is also susceptible to damage from heat and sunlight. "Poly" rope is widely used because it is readily available and much cheaper than all other synthetic ropes. Polyethylene rope also floats in water, making it useful for boat and dock work. ===================================================================== *** INSTRUCTORS PLEASE NOTE *** See Table 1.1 for description of different types of rope. ===================================================================== a. Wire rope is normally used for extra heavy pulling or lifting jobs. It is also commonly used in fencing. Wire rope consists of steel wires wrapped around a fiber or smaller wire rope core. The solid core of the wire rope makes it very rigid and difficult to work. The steel must be oiled or greased to prevent rusting. Wire rope is many times more expensive than synthetic and natural fiber ropes. B. Caring for Rope 1. Inspect ropes regularly for nicks, cuts, and abrasion damage. a. Avoid dragging rope over rough or damaged surfaces. b. Avoid stepping on or laying heavy objects on rope. c. Use synthetic ropes where rope may come in contact with oils, acids, or chemicals. d. Whip or splice the ends of rope to prevent unravelling. 2. Proper storage can increase the longevity of ropes. a. Do not store synthetic ropes where they will be exposed to heat or sunlight for long periods of time. b. Rope should be stored coiled and in a dry place. c. Hang ropes off the ground. Table 2 Types of Rope Available for Restraining Livestock1 _____________________________________________________________________________ Type of - - - - - - Breaking Strength (pounds) - - - - - - - Fiber 3/8" 1/2" 5/8" 3/4" 1" _____________________________________________________________________________ Cotton 890 1,450 2,150 3,100 5,100 Sisal 1,080 2,120 3,250 4,320 7,200 Manila 1,350 2,650 4,400 5,400 9,000 Polypro- 2,650 4,200 5,700 8,200 14,000 pylene Nylon 4,000 7,100 10,500 14,200 24,600 _____________________________________________________________________________ Advantages Disadvantages Suggested Uses _____________________________________________________________________________ Cotton soft, flexible least strong tying of animal least likely to low abrasion limbs cause ropeburning resistance neck ropes intermediate will rot and hobbles in cost deteriorate lead ropes, if 5/8" or larger Sisal same as manila, except that sisal is 75-80% the strength of manila Manila good strength for subject to some use as a natural fiber rope rotting lariate--not has good "grass" harsh on hands suggested for rope "feel" likely to cause tying animal ropeburning limbs (legs) lead ropes, if 1/2" or larger Polypropylene very strong, second rope burning good for lead only to nylon and is likely ropes dacron flame or heat excellent for will not rot will cause slinging and resistant to barn-yard melting total restraint acids and bases Nylon highest strength will stretch strongest lead of any rope very likely to rope available will not rot from cause ropeburning excellent for water or mildew flame or heat slinging and will cause melting total restraint d. Wet rope should be dried in the shade in the open air before coiling and storing. This is especially important when handling natural fiber ropes which are susceptible to rot and mildew. e. Remove all kinks from the rope before storing. 1) To remove kinks, lay the rope out full length and drag one end for about one-half the length of the rope. 2) Prevent kinks by coiling the rope in the same direction in which the strands are laid. f. Remove all knots from the rope before storing. 1) Knots decrease the breaking load of ropes. A single overhand knot decreases the strength of the rope by 65%. g. Secure the ends of ropes to prevent fraying. 1) Use an end splice or whip the ends of natural fiber ropes. 2) Melt the ends of synthetic fiber ropes or dip them in adhesive. 3. Lubricate wire ropes with oil or grease and prevent exposure to water to avoid rust problems. C. Working Safely with Rope 1. Most injuries involving the use of rope come from three factors: a. Rope burns b. Broken ropes c. Entanglements 2. To avoid injuries from rope burns: a. Wear leather gloves when doing work with rope. b. Do not wrap the rope around hands when working with livestock. c. Do not attempt to grab a rope that is moving under a load, or a fast moving rope. 3. To avoid injuries due to the breaking of ropes: a. Never stand, crawl, lie, or walk under heavy objects supported by ropes or cables. b. Never tow vehicles with a rope that is not designed for towing. Special nylon ropes are manufactured for this purpose. c. Always use a rope with the proper working strength for the job. d. Remove all knots from the rope that will reduce the working strength. e. Check the condition of the rope frequently. f. Never stand near a rope or cable that is under heavy stress. A cable or a rope breaking under these conditions can cause severed limbs and other serious injuries when it whips around. 4. To avoid injuries due to entanglements: a. Always stay away from moving ropes. b. Never wrap the rope around your hand or body for support. _____________________________________________________________ ACTIVITY: 1. Collect different sizes and types of rope. Have an identification quiz at the end of the period. 2. Have the students practice coiling rope. Divide the class into teams and have a relay race coiling the rope. 3. Bring samples of damaged ropes to class. Inspect the ropes for damage and identify methods of either preventing or repairing the damage. 4. Demonstrate the weakening effect of knots on rope. String can be used instead of thick ropes. Hang objects from the string that has no knots. Then tie overhand knots in the string and see if the same amount of weight will break it. _____________________________________________________________ 6/13/91 RRE/tf #%&C