ROPE MAKING Grade Level: 5-12 th grades Objectives: 1. Youth understand rope structure by twisting fibers into yarn and then twisting yarns into rope. 2. Youth understand the function of a rope making machine and suggest better machine designs. 3. Youth use the Internet to research traditional and modern technologies, history, and science of rope making. 4. Youth work with others to link project to community. NYS Learning Standards: Math, Science, and Technology Students access, generate, process, and transfer information using technologies. Students apply technological knowledge and skills to design, construct, use and evaluate products. Students use mathematical analysis, scientific inquiry, and engineering design to pose questions and develop solutions. National Science Standards: Content - Grades 5-12 Science as Inquiry Ability to do scientific inquiry (5-12) Science & Technology Abilities of technology development (9-12) Understanding about science and technology (5-12) Science in Personal & Social Perspectives Science and technology in society (5-8) Natural Resources (9-12) History and Nature of Science Science as a human endeavor (5-12) History of science (5-8) Historical perspective (9-12) Vocabulary Elasticity Ability of a material to stretch and then return to its original shape. Flexibility Ability of a material to bend without breaking. Lay The amount of twist in the rope as in hard lay, regular lay, and soft lay. Rope A cord made by twisting together fibers. Strength Durability in terms of breaking, tearing, or puncturing. Water Resistance Ability to resist moisture uptake. History No one knows when the first rope was made. We do know that sailors, builders, hunters, and farmers have long depended on rope to move and control animals, structures, and machines. Conventional ropes were used in China as early as the 28 th century BC and are depicted in Spanish cave paintings dating back 20,000 years. Egyptian ropes from 2,600 BC and ropes carried by early Romans are still intact, and on view at museums. In the US, the ropewalk was one of the earliest industries, established in Boston in 1642. The Plymouth Cordage Company, founded in 1824, was world famous and produced ropes for more than a century before being sold to Columbian Rope (now also closed) in Auburn, NY. The US Navy used steam power to make rope at its Charlestown yard from 1837 to 1971. Early ropes were made by hand, using cotton, dogbane, sisal, jute, hemp, flax, abaca (manila hemp), coir (coconut husks), leather, or hair. This changed with mechanization and the development of nylon in 1938. Today, most ropes are made in factories from petroleumbased synthetic fibers. 1
Science Ropes need to be elastic, flexible, and strong. High-quality ropes should not be damaged by abrasion, heat, water, salt water, sunlight, or microbes. To achieve these properties, rope manufacturers manipulate materials and structure. For example, jute is hard and coarse; hemp is lightweight and strong; and abaca resists salt water. Synthetic fibers, such as nylon, polyester, and polypropylene, are stronger than plant fibers, but they melt at lower temperatures and break down faster in bright sunlight. Aramid fibers (Nomex, Kevlar, and Hyten) are made from long chain, synthetic polyamides and offer exceptional strength and resistance to heat and water. Rope strength also depends on the degree of twist (lay) and the cord structure. The greater the twist, the stronger the rope. The greater the number of strands, the stronger the rope. Common rope structures are: twisted, braided, plaited, parallel core and fiber, and wire rope. Twisted ropes have good stretch and flexibility; braided ropes are more stable; plaited ropes are easier to grip. Both the parallel core and fiber and the wire rope constructions have an inner core of twisted fibers covered by a braided jacket for high strength and resistance to abrasion. How Big Can Rope Be? In this activity, any item is called rope if it exhibits the twisting construction described in the Technology section (opposite). Some authors, however, are more specific. Cordage is the general term for flexible cords with thread, string, twine, rope, and cable being used to indicate increasing size. For the purist, rope is cordage one inch or more in circumference. Technology Rope technology progressed from hand twisting and braiding > simple mechanical tools > compound mechanical tools > power machinery. Hand twisting demonstrates the general principle of rope making. Groups of fibers or yarns are twisted in one direction to form larger stands, which are then twisted together in the opposite direction to form a cord. When subjected to tension, the tendency for the individual strands to untwist is opposed by the tendency of the rope as a whole to untwist in the opposite direction. Fibers twisted into yarns Yarns twisted into strands Strands twisted into rope Both the Egyptians and Southwest Native Americans (1,000AD) are thought to have made short ropes using a simple static device that resulted in one twist of the strand/rope for every twist of the device. In the 13 th century, Europeans introduced the ropewalk, a method for making the long ropes (300 yards or more) required by tall ships. The ropewalk relied on a compound mechanical tool called a jack that allowed for multiple twisting of the strands/rope. Early jacks had a large center wheel (flywheel) attached by pulleys to smaller wheels fitted with hooks. For each turn of the flywheel, the smaller wheels would turn 4 to 10 times. By the Renaissance period, pulleys were replaced by gears. Geared machines were scaled down to serve the needs of America s small farmers and ranchers and it is these cast iron rope makers that one finds today in antique shops. For a while, small machines powered by people and large machines powered by various types of energy co-existed. Today, factories around the world produce uniform, highquality rope very quickly and economically. 2
TOOLS: Build a Rope Machine Time Required: 2 hours Materials: Plywood (upright) 1 piece 4-inch width x 4-inch length x 1 / 2 -inch thick Plywood (base) 1 piece 4-inch width x 6-inch length x 1 / 2 -inch thick Plywood (paddle) 1 piece 3-inch width x 9-inch length x 1 / 2 -inch thick. Plywood (separator) 1 piece 3-inch width x 9-inch length x 1 / 2 -inch thick Plywood (holding device) 1 piece 1-inch width x 9-inch length x 1 / 2 -inch thick. No. 9 wire (or coat hangers), 3 pieces of 6-inch length 3 wood screws 1 long screw eye 2 nuts/washers for screw eye Clamps Drill and bits Wire cutters or pliers Saw Screwdriver Safety glasses Sandpaper Wood glue Terminology: Crank - wire hooks on the rope machine that twist the rope strands. Holding Device a strong object that holds the strands together while they are twisted. Paddle wooden piece that attaches to the cranks, turning all cranks with one motion. Instructions: 1. Sand all wooden parts smoothing corners. 2. At one end of the upright board, mark with a pencil the position for three screws 1 / 2 -inch from the end, 3 / 4 -inch from the sides, and 1 1 / 4 -inch apart. 3. Place the base in a clamp and apply glue to one end. 4. Press the upright to the glue-covered end of base and secure with wood screws. 5. Mark and drill three small holes in the upright for the wire hooks. Place the first hole in the center of the upright, 2 inches from the sides and the ends. Place the second and third holes 1-inch from the bottom and 1-inch from each side. The three holes form a triangle. Separator a notched device that separates the strands as they twist. Also called wrench. Notes: 3
You may vary the dimensions of the rope machine to accommodate materials you have on hand. In general, larger machines are needed for heavier rope. This rope machine is for making 3- strand rope. If you want to make 4- strand rope, you need to provide 4 hooks and make 4 notches on the separator. You can substitute large sturdy forks for the separator. Plywood is available in 4 ft. x 8 ft. sheets. Home supply stores often carry half sheets (4 ft. x 4 ft.) or smaller, and some will custom cut pieces for a nominal fee. Craft stores also may have small pieces. Rope Machine Instructions (continued) 6. Insert the lengths of wire into the holes on the upright. 7. On the inside, shape a hook of approximately 0.5- inch diameter. On the outside, bend the wire to form a crank with two kinks. Rope Machine Challenge! After using this rope-machine, some folks suggested ways to improve it. We encourage you to think of possible improvements, and even to build your version of a new and improved rope machine. Compare it to ours and see which works better. Try using different materials can you build a rope machine from things you recycle? What makes the best holding device or the best separator? Test your ideas and let us know! Rope Machine Sources Rope machines are available for purchase at these websites: Lehman s <www.lehmans.com> Make Rope <www.makerope.com> Schacht Spindle Co., Inc. <www.schachtspindle.com/hw_rope machine.htm> The Toymaker s Workshop <www.toyworkshop.com/inventions. html> (battery-powered Crazy Cords) 8. Shape one end of the paddle as a handle by shaving approximately ¾-inch of wood from each side for a length of 5 inches. 9. Drill three small holes in the paddle, duplicating the triangular pattern on the upright. 10. Cut three notches 1-inch wide and 1-inch deep into one end of the separator (one notch in the end and two on the sides). This separator is for making 3-strand rope. 11. Optional: A swivel holding device. Mark the center on a piece of wood, approximately 1-inch width x 9-inch length x 1 / 2 - inch thick. Drill a hole at the mark penetrating the wood. 12. Place a nut and washer on a long screw eye and insert the screw eye into the hole in the wood. Secure with a second nut and washer. The screw eye should rotate freely. 4
TECHNIQUE: Make Rope Making rope is quick and easy, so experiment with different fibers, yarn sizes, and colors. Time Required: 30 minutes Materials: Cotton, sisal, jute, hemp, sweet grass, abaca or other fibers or yarns Rope making machine Holding device (dowel, screwdriver, or swivel device on previous page) Masking tape Rope Uses: Even if you don t plan to make rope for a major ocean voyage, your cord will come in handy for other uses: Belt Handle Bookmark Keychain Bracelet Necklace Plant hanger Coil basket Rugs/doormats You can also have fun using your rope to learn different knots. Instructions: Make 2-Strand Rope by Hand 1. Gather a small bundle of yarns half the thickness of the finished cord. If using crochet thread, four 20-inch yarns are easy to handle. 2. Fold in half and tape the fold to a table. 3. Hold half the ends in your right hand and half in your left hand. 4. Twist both sets of yarns in the same direction until they achieve the desired twist. 5. Form a cord by twisting together the two yarn sets in the opposite direction to the twist in Step 4. Instructions: Make 3-Strand Rope by Machine 1. Measure three pieces of yarn, each twice as long as the rope you want to make. 2. Place yarn loops over the three hooks, tie the loose ends in an overhand knot, and place over the holding device. The holding device can be secured to a table or wall or a partner can hold it. You may also choose to use the swivel holding device described in Steps 10 and 11 on the previous page. 3. Place the paddle over the straight ends of the wire cranks. When the paddle turns, all three hooks also turn. 4. Insert the separator between the machine and the holding device placing one yarn strand in each notch. 5. Turn the handle and watch the yarns twist. When the three looped yarns are tightly twisted, they begin to twist together into a 3-strand rope. Move the separator forward to accommodate the rope formation. You may need to occasionally straighten the yarns and experiment with tension to obtain the type of rope you want. 5
INTERNET RESEARCH: History, Science, and Technology While making rope you may have wondered: how to find specialty ropes such as lariats, bungees, and jump ropes, or ropes for rock climbing, parachuting, or firefighting? how many different types of rope machines exist? which countries export plant materials for rope and which countries dominate rope manufacturing? how ropes are made in factories? which museums house rope collections? Searching the Internet is a great way to answer your questions and to locate other information about rope. For example, you could learn how ropes are used to prevent oil spills. A 1996 International Maritime Organization resolution states that all tankers carrying 20,000 tons or more of hazardous materials must have an emergency towing system. That system includes Kevlar or wire rope for towing disabled vessels. Compare the properties, manufacturing process, and cost of ropes made from Kevlar and steel. Another suggested topic is abaca fiber, a material that is three times as strong as cotton and extremely resistant to salt water. For years, abaca was the material of choice for marine cordage. Find out where it is grown and why we use the term manila folder. Keywords Related to Rope Making PLANTS TECHNOLOGY TEXTILES (rope) Abaca (Manila Hemp), Musa textilis Flax, Linum usitatissimum Hemp, Cannabis sativus Indian Hemp, Apocynum cannabinum L. Sisal Agave sisalana Toad flax, Linaria linaria Braid Columbian Rope Co. Jack Paddle Ply Plymouth Cordage Rope Machine Rope Walking S-twist Separator Whitehill Mfg. Corp Wrench Z-twist Bast Cord Cordage Kevlar Hyten polyamide Lariat Nomex Nylon Polyester Rope Spectra Twine Wire Rope References: 1. Boy Scouts of America, Knots and How to Tie Them, BSA, Irving, Texas. 1978. (Printing 1992) 2. Davis, Greg. Making Rope with a Hand Operated Rope Machine. 2001. 3. Findley, Gerald. Rope Works. 1996. 4. Nelson, John. The History of Rope making. 2002. <http://www.rope-maker.com/ropehistory.html> 5. Roper, John. Got Rope? <http://www.rope-maker.com/index.html> 6. Royal Botanic Gardens, Kew. Rope-making. http://www.rbgkew.org.uk/ksheets/rope.html 7. USDA. Industrial Hemp in the United States: Status and market Potential. 2000. <http://www. globalhemp.com/archives/government_research/usda/hemp_study_2000_summary.shtml> 6
EXPANDING THE ACTIVITY: Fieldtrips: Do You Know the Ropes? Visiting a museum is a good way to integrate the historical aspects of rope making into this project. Below are some suggested New York sites, but a nature center, pioneer village, or historical exhibit in your area might better fit your curriculum. The New York State Museum Cultural Education Center Empire State Plaza, Albany, NY Tel: 518-474-5877 http://www.nysm.nysed.gov/ See the Iroquois exhibit for items related to rope making. The Farmer s Museum Cooperstown, NY Tel: 888-547-1405 http://www.farmersmuseum.org/ View exhibits that include information about rope fibers, tools, and products. Visit the gardens with flax and dogbane plants. South Street Seaport Museum 207 Front Street, New York Tel: 212-748-8610 http://www.southstseaport.org/ Explore the maritime history of rope. Adapting the Activity Make cordage from plant fibers. Use the rope you made to make plant hangers and coil baskets. Hang different sized ropes from the ceiling and attach cloth leaves to simulate a rainforest in a corner of the classroom. Make a rug. Dye sturdy cotton cloth with indigo or use old denim garments. Tear fabric into narrow strips. Use the rope maker to create a three-ply "rope". Coil the rope into an oval or round shape, stitching the coils loosely together to make a "braided" rug. On the Ropes... In 1887, the Queen Victoria Park Commissioners prohibited tight-rope walkers from anchoring their ropes to the gorge walls near Niagara Falls to discourage daredevil stunts over the falls. Polypropylene is the only rope material that floats. The Incas of Peru kept financial accounts using knotted ropes. Rope courses have been popular in the US since the early 1960s as part of outdoor recreation, professional development, and skill-building programs. Chasms in Nepal, China, and other mountainous countries are sometimes spanned by rope bridges. USA Jump Rope National Records as of 2007 were: Guys Record Age Score Year (jumps per min) 11 and under 320 2001 12-14 343 2002 15-17 346 2007 18 and over 359 2007 Gals Record Age Score Year (jumps per min) 11 and under 324 2003 12-14 359 2006 15-17 367 2007 18 and over 350 2007