Rigging PART A Flashcards
Only One type of natural fibre rope is sturdy enough for lifting what is it
Number one grade manila
Fibre rope is constructed by what method
Reverse twisting
How are ropes formed
Fibres right hand twisted into yarn, several yarns are left hand twisted into strands. Then 3or 4 strands are right hand twisted to form a right lay rope. Reversing this is a left lay rope
What rope is used for most general purposes
Medium-lay rope
These ropes provide more abrasion resistance
Hard lay ropes
These ropes have higher tensile strengths
Soft lay ropes
Two types of synthetic fibre rope commonly used
Nylon and polypropylene
What synthetic rope is excellent for use in such industrial applications as anchor and tie up lines tag lines and couplers and safety ropes
Nylon
Rope is light in weight, does not absorb moisture, and floats on water, and the most popular rope available
Polypropylene rope
What does it mean when a yard is broken
The rope has been overloaded and is not safe for hoisting
If a rope is frozen do you let it thaw before using
Yes
Cutting a natural rope what do you do
Ends must be taped or whipped with fine twine
How efficient is a rope with a knot in it
50%
How efficient is a straight line pull
100%
How big does a sheaves diameter need to be greater than the ropes diameter
6-10x
T or F the plumbing industry tends to use wire rope as lashing
True
Ropes with many wires to a strand have a good resistance to what
Bending fatigue
Wire rope grade Used where maximum tensile strength is required, such as mine shaft hoisting
Grade 120/130 - special improved plow type 11
Wire rope Used where a higher ultimate load (UL-BS) is required
Grade 115/125- special improved plow type 1
The grade most commonly used for wire rope, it combines tensile strength wear resistance and fatigue resistance
Grade 110/120 improved plow
Wire rope that Has excellent wear and fatigue resistance but a lower tensile strength
Grade 100/110- plow
What method is used for constructing fibre rope
Reverse twisting
How to calculate working load limit
Diameter squared X 8= WLL in tons
Type of connection recommended in all hoisting slings with a sling eye
Flemish eye plus a pressed metal sleeve
Synthetic webbing slings are weakened and damaged by
Repeated use of hoisting rough and sharp edged objects
The preferred material for synthetic webbing slings
Nylon
Capacity of a double ply sling over a single ply sling
140% -200%
Chain that is suitable for construction hoisting is stamped with what
Identifying letter or number in the links
Usually letters A and T or versions of the number 8 as 80 or 800