Chapters 3 & 4 Flashcards
The Back Splice prevents what?
The Back Splice prevents the end of a rope from fraying and is not subject to loading.
Identify the locations of a rope when tying a knot:
- The standing point: The longest part of the rope
- The running end: Is the free end of a rope used to form a knot
- The bite: is a loop formed by placing the running end of the rope parallel to the standing part of the rope
The efficiency rating of an Eye Splice
95%
The efficiency rating of a Short Splice
90%
The efficiency rating of a Bowline
65%
The efficiency rating of a Clove Hitch
60%
The efficiency rating of a Square Knot
60%
The efficiency rating of Knots that Choke
50%
The weakest point of a rope is?
At the knot or splice
If a rope’s catalog breaking strength is 1000 pounds and a bowline is tied in it, the rope will break at how many pounds?
650 pounds
1000x0.65=650
If a rope’s catalog breaking strength is 1000 pounds and a running bowline is tied in it, the rope will break at how many pounds?
500 pounds
1000x0.50
When installed correctly, _______ are almost as strong as the rope itself, whereas a ____ can significantly reduce the strength of a rope.
splices, knot
Name the 3 different types of rope used in the power delivery industry.
- Natural Fiber
- Synthetic Fiber Rope
- Wire rope
Manilla rope has limitations because?
It is subject to rot, and many companies prohibit its use entirely.
What conditions must exist on a natural fiber rope for OSHA demand that it be immediately removed from service?
- Abnormal wear
- Powered fiber between strands
- Broken or cut fibers
- Variation in the size or roundness of the strands
How is synthetic rope different from natural fiber rope?
Synthetic, or man made, fiber ropes have individual fibers running their entire length, rather than short overlapped fibers.
Characteristics of Duraplex rope:
- Each strand consists of a combination of polyester and olefin fibers which produce an excellent strength to weight ratio.
- Breaking strength: 6700lbs
Characteristics of Tenex rope:
- This rope is Samthane coated polyester with excellent abrasion resistance and durability in addition to its high strength.
- Breaking Strength: 11800lbs
Name the different types of wire rope used in the power delivery industry.
- Mild plow steel wire rope
- Plow steel wire rope (stronger than mild plow)
- Improved plow steel wire rope (stronger than plow)
________ plow steel wire rope is considered to be the strongest.
Improved
Ropes should be _____ and ___ when stored.
clean, dry
Ropes should be hung how?
In neat coils devoid of kinks or twists.
True or false: Chemicals are not known to damage ropes and is not possible for them to weaken the strength of the rope.
False
How often should you remove debris from ropes?
At every opportunity.
Catalog Breaking Strength (CBS) is:
The average force in pounds needed to break a rope.
Working Load Limit (WLL) is:
the maximum load that should ever be applied to the rope.
Define: Design Factor
An arbitrary number (usually 5 for ropes) used for calculating WLL. The CBS is divided by the Design Factor to determine the WLL.
Define: Dynamic Loading
occurs when ropes are subject to sever exposer conditions.
What are some examples of Dynamic Loading?
- Shock loading
- Excessive use
- Exposure to high temperatures (elongates the strands)
- Extended periods under load
