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TROOP 4/CREW 4 ROPE/BASIC KNOTS/BASIC LASHING PRESENTATION - By Matt Hannam. Cleaning and Care of Rope. Definitions
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TROOP 4/CREW 4 ROPE/BASIC KNOTS/BASIC LASHING PRESENTATION - By Matt Hannam
Definitions • A knot is a rope intertwined within itself, or with another length of rope. • Stopper knots are used to stop the end of a rope fraying, or to stop a rope from running through a small hole, appliance or constriction. • A bend is a knot that joins two ropes together. • Bight - a double section of rope usually taken from the center of the rope, that does not cross over itself. • Loop - a turn of the rope that crosses itself. • Free End - the end that is not rigged, the end one can work with. • Standing End - the end that one cannot work with, it is usually fixed to something or too long to work with. • Jam - when the knot tightens under tension and you cannot get it undone, knots that jam (i.e. overhand knots) should be avoided.• Finishing the knot involves "dressing" it and then "setting" it. Dressing is the orientation of all knot parts so that they are properly aligned. Failure to do this can result in a great reduction in knot strength or failure of the knot. Setting a knot involves tightening all parts of the knot so that all the parts are touching and causing friction upon other parts of the knot thus rendering it operational. • Slippery - tying a knot with the free end passed back through the knot so that when pulled the knot comes undone.
Rope Construction Most rope and cords generally available are either made of nylon, polypropylene, sisal or cotton. Sisal and cotton are generally used for smaller lines or cords that have commercial or domestic uses (Butcher's Cord or Bailer Twine). Polypropylene is a very popular rope material as it is inexpensive and it floats – a most useful characteristic for any rope that is to be used around water. Nylon rope of similar diameter is stronger, but usually more expensive and nylon does not float. Ropes are usually either of: a three strand twisted construction, a multi-strand braided, or kermantle construction. Kermantle construction involves a sheath and an inner core. Kermantle rope of a similar diameter to a twisted rope is usually stronger, stretches more, is more flexible and easier to work with.
Rope Size Sisal Cord / Cotton Butchers Cord / Binder Twine - these light anD inexpensive cords are most useful for lashings where many wraps of the cord will carry the load. 1/8" or 3 mm cord / Sash Cord - useful for very light loads, heavy duty lashings, clothesline, or guy lines on small tents and tarps. 3/16" or 5 mm cord - useful for tying on light loads to vehicles, guy lines on heavier tents or large cook area tarps. 1/4" or 7 mm rope - preferred size for tying canoes onto trailers and vehicles, strong enough, but it still allows some stretch to maintain a pressure over a period of time. 3/8" or 9 mm rope - preferred size for throw bags and painters, or anytime one has to occasionally haul on the rope with bare hands, but storage is also a consideration. ½" or 11 mm rope - the standard size for "single line" climbing ropes.
Knots Weaken Rope They do! A great deal is written about which knots weaken a rope most. An angle, a kink, or a knot, stresses the fibers unevenly and weakens the rope. If this concerns you, you are using rope that's too thin!! Although some knots in some ropes are claimed to only weaken a rope to about 80% of its rated strength, other knots weaken a rope to about 50%. It is therefore simpler, and certainly safer, to assume that even brand new rope will perform at no more than 50% of its rated breaking strength. And, if the rope is old, worn, or damaged by sunlight or chemicals - expect considerably less.
Simple Whipping. All ropes should have their ends treated in some way to stop them from fraying or becoming un-stranded. A whipping will fail if it is not tight and tidy.
Step 1 Step 2 Step 3
The Timber Hitch (Lumberman's or Countryman's Knot)
The Rolling Hitch (Taut Line Hitch)
TRIPOD LASHING Lay three poles alongside each other with the top of the center pole pointing the direction opposite that of the outside poles. Tie a clove hitch around one outside pole. Loosely wrap the poles five or six times, laying the turns of the rope neatly alongside one another. Make two very loose fraps on either side of the center pole. End with a clove hitch. Spread the legs of the tripod into position. If you have made the wraps or fraps too tight, you may need to start over.
