Rigging Basics Flashcards
(62 cards)
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%