Ropes and Knots Flashcards
What are the two types of Rope?
- Natural Fibers
- Synthetic Fibers
What is the most common rope used by Edison for Lineman?
1/2” Synthetic Fiber Rope. Used for Handlines and many Rigging Operations.
What are the two ropes used for “heavier rigging applications?”
- 3/4” Synthetic Fiber Rope, “Bull Line”
- 1” Synthetic Fiber Rope, “Sand Line”
What other type of rope is used?
1/4” Cotton Rope is sometimes used for a wide variety of low weight operations.
How do you prolong the life of rope?
- Ensure that rope is dry and stored in a cool, dry place. This reduces the possibility of mildew and rotting.
- Coil it on a spool or hang it from pegs in a way that allows air circulation.
- Avoid dragging it through sand or dirt or pulling it over sharp edges. Sand or grit between the fibers cuts the, and reduces the rope’s strength.
- Slacken taut lines before they are exposed to rain or dampness because a wet rope shrinks and may break.
- Avoid exposure to excessive heat and fumes of chemicals; heat or boiling water decreases rope strength about 20%
How should rope be inspected?
- Mildewed rope has a musty odor and the inner fibers of the strands have a dark, stained appearance. Broken strands or broken yarns ordinarily are easy to identify. Dirt and sawdust-like material inside a rope, caused by chafing, indicate damage.
- In rope having a central core, the core should not break in small pieces when examined. If it does, this is an indication that a rope has been over-strained.
What should you do when you find rope to be unsatisfactory?
Destroy a rope, or cut it up in short pieces to prevent its being used in hoisting. You can use the short pieces for other purposes.
What is the efficiency rating for an Eye Splice? Short Splice?
- 90%
- 80%
What are the efficiency ratings for a Timber Hitch and a Half Hitch?
65%
What are the efficiency ratings for a Bowline or a Clove Hitch?
60%
What are the efficiency ratings for a Square Knot or a Sheet Bend?
50%
What is the efficiency rating for an Overhand Knot? and when or how is it used?
45%
- Often tied in the end of a rope to prevent the strands from unraveling or as a stop knot to prevent rope from slipping through a block.
Why or how is a square knot used?
Used to tie two ropes of approximately the same size. It will not slip and can usually be untied even after a heavy strain has been put on it. Lineman use the Square Knot to bind light leads lash poles together on changeovers on slings to raise transformers and for attaching blocks to poles and crossarms.
What is the Bowline used for and what is its nickname?
“The King of Knots” Used to place a loop in the end of a line that will not slip or pull tight.
- Attach come-alongs (wire grips) to rope
- Attach tail lines to hook ladders
- As a loose knot to throw on conductors to hold them in the clear while working on poles
What is a Bowline on a Bight used for?
To place a loop in a line somewhere away from the end of the rope. Makes a good seat.