Crane Class 1 Flashcards
Duty cycle
Relative operating in a short cycle
Running wire rope
Wire rope running over a sheave
Periodic inspection
With records kept for at least 3 months
Lay length
Horizontal distance of one rotation of a strand on the wire rope
Rope lay
Signifies the rotation of wire and strands
Safety factor of regular lay wire rope while hoisting personnel
7 to 1
The dead end of a wire rope should never be less than?
6 inches
When using rotation resistant wire rope on a becket the tail should never be less than
20 diameters of the wire rope
What are the 5 parts that make up a wire rope?
Wire
Center wire
Strand
Wire rope core
Wire rope
Which is the number of strands and which is the number of wires per strand?
6x19
6 strands 19 wires per strand
Regular lay
Wires and strands that fall in opposite directions
Lang lay
Wires and strands that fall in the same direction
Rigging wire rope removal criteria
10% broken wires in 8 rope diameters
How do you measure wire rope and how many times?
Crown to crown
3 times for 6 strand wire rope
4 times for 8 strand wire rope
What is the termination efficiency of a wire rope clip turn back eye?
90% 1” and over
80% under 1”
Nylon choker his has ___ capacity of a single leg sling
75% the capacity
Double choker hitch has ____ capacity of a bridle at the same sling angle
75% capacity
What is the D/d ratio of a basket hitch?
25/1
What is the safety factor of IWRC (Independent Wire Rope Core)
7/1 for rotation resistant
10/1 for personnel lifting
What is the design factor for wire rope and synthetic slings?
5/1
What is the design factor for chain slings?
4/1
What is the formula for determining safe working load SWL of a wire rope sling?
Diameter of the sling multiplied by itself then multiplied by 8 or:
d x d x 8 = SWL
How do you determine if the ultimate breaking strength UBS of wire core, wire rope?
Diameter of the wire rope multiplied by itself, multiplied by 45 or:
d x d x 45 = UBS
What is the safety factor of rotation resistant wire rope?
5/1
Wire core wire rope is ___% stronger than fiber core wire rope
7.5%
What are the 3 types of shackles?
Safety pin
Bolt type
Screw type
What does D/d stand for?
Diameter to diameter ratio
Big D = diameter of the object the wire rope sling goes around
Little d = diameter of the wire rope sling
Sorting hooks (pelican hooks) should be used at what angle and up to what WLL?
45 degree angle and a 7.5t WLL
2t WLL when tip loading
3 wire rope lubricant criteria
Non corrosive
Recommended by manufacturer
Cannot hinder inspection
Termination efficiency of a Flemish eye?
90%
Termination efficiency of a wedge socket
80%
Termination efficiency of a spelter socket
100%
Reasons for wire rope removal
Electrical contact
Crushing
Birdcaging
Core protrusion and wear
Turnback eye formula for number of clips needed
3 times the diameter of the wire rope plus one
1” wire rope: 4 clips
1 x 3 + 1 = 4 clips
Removal criteria of wire rope sling
5 broken wire in one strand in one lay or 10 broken wires in one lay
Maximum included angle of a hook
90 degrees
Maximum included angle of a shackle
120 degrees
Wear criteria of a hook
5% critical areas
5% or 1/4” throat opening
10% other areas
What is fleet angle
The angle between a line drawn from the tip of the boom to the ground and a line drawn from the boom tip to the outermost flange point
Removal criteria of wire rope
1/3 of the original dimension
Rejection criteria for chain slings
10% wear
5% stretch
Weld splatter
Twists
Gouges
Excessive nicks
Kinks
Wire rope sling capacities
Two legs 200%
Single leg 100%
Single choke 75%
