Rigging Basics Flashcards
What does proper rigging reduce?
The risk of personal injury and prevents damage to equipment, and make the most strenuous lifting tasks relatively easy.
What is a rope?
A group of fibers or strands which are twisted or braided together in order to combine them into a larger and stronger form.
What are the two broad fiber rope groups?
- Natural fibers
- Synthetic fibers
What are the most common rope types used by SCE Linemen?
Combination Polyester and Polypropylene
What are cotton ropes are generally used for?
A backup, or in addition to, synthetic ropes. Also used for a wide variety of low weight/low consequence applications.
What does a rope’s diameter determine?
It’s Working Load Limit (WLL)
How do you determine WLL?
Breaking Strength divided by Safety Factor
Generally, what size ropes are synthetic ropes?
1/2” and 3/4”
What size rope is most commonly used for handlines?
1/2”
What is a common name for 3/4” rope?
Bull Line
What size is Cotton Line typically?
3/8”
What size rope is used for truck sand lines?
7/8”
What would shorten the lifespan considerably of fiber rope?
Improper Care
How do you prolong the life and strength of fiber rope?
- Ensure that rope is dry and stored in a cool dry space.
- Coil it in a spool or hang it from pegs in a way that allows air circulation
What should you avoid doing with rope?
- Dragging it through sand or dirt or pulling it over sharp edges. Sand or grit between fiber cuts the and reduces the rope’s strength.
- Exposure to excessive heat and fumes from chemicals; heat or boiling water decreases rope strength by about 20%
If a rope becomes wet, what should it be considered as?
A conductor
What qualities does a good knot have?
- The right knot for the application
- Easy to tie
- Does not overly compromise the strength of the rope
- Is easy to untie
What are the eight rigging knots?
- Square knot
- Half Hitch/Two Half Hitches
- Bowline
- Bowline on a Bight
- Clove Hitch
- Timber Hitch
- Eye Splice
- Short/Butt Splice
What does tying a knot do to a rope?
Decrease the strength of the rope
What is a rule of thumb to remember about knot deficiency ratings?
A knot reduces its efficiency by 40%-50%
What is a rule of thumb to remember about splice deficiency ratings?
A splice reduces its efficiency by 10%-15%
What is the efficiency rating of an Eye Splice?
45%
What is the efficiency rating of a Short Splice?
80%
What is the efficiency rating of a Timber Hitch or Half Hitch?
65%