What is the 6 ' Rule Method for Calculating Sling Stress?
T= W/N X L/V
Tension= Weight of Load/Number of Slings multiplied by Sling Length/ Vertical Distance
When Making a Three Point Lift , how many sling legs are assumed to be supporting the load?
2
Name the Three Main Aspects of Successful Rigging?
Safety, Communication, Control
Shackles with screw pins are sized by the what?
Bow
What is the Formula for Block Loading( Single Part Line) ?
Block Factor of Single part Line X Line Pull
In a Frictionless single line pull is the load being dragged or lifted?
Lifted
When the Skyline deflection increases what happens to the tension on the Skyline?
Decreases
When lifting an object that is of an irregular shape and the total weight calculated you must then always find what?
The Center of Gravity
In a frictionless system, the load is 100 lbs, What is the Line Pull on the Tugger
100 lbs
Can you use the load cell in a crane and pick up the object to determine its weight if needed?
No
Knots shall not be used to configure synthetic rope slings because knots do what?
Reduce Strength
What is the safety factor applied to (most) rigging hardware when calculating the load weight and equipment required for a hoisting job___? What about Personal?
5 to 1
10 to 1 for Personal
What is the line pull in theory on a 5 part line lifting a 2500 lb load?
500 lb line pull
If the Center of Gravity is above the lowest point of attachment the
C. The load may be unstable
The main purpose of a spreader bar is to
B. Stop the load from bending
When the skyline deflection decreases, what happens to the tension on the skyline?
Increases
Slings should be inspected:
C. At each use
The square knot is used to :
A. tie two ropes (dry) the same size
What type of hitch produces a 360 degree contact with the load and tightens as the lift takes place?
Double Wrap Choker Hitch
What would be the approximate single line pull required to lift a 1500 lb load with block rigging with five parts of line?
300 lbs
At what angle will each sling leg be equal to that of the actual load?
30 degrees
Before every hoisting operation it should be agreed upon who?
B. Will be the signal Person
What is the lay length of wire rope?
It is the straight linear distance of one strand as it makes a complete revolution.
How is wire rope measured?
Across the diameter at its widest point
What is the rule of Thumb WLL (SWL) formula for finding the WLL for a wire rope sling?
D2 x 45 / 5 = WLL(SWL) in tons
A choker hitch is rated at what percent of a single vertical hitch?
75%
What is the sling load angle factor at 30 degrees?
2.00
What is the sling load angle Factor at 45 degrees?
1.414
What is the sling load angle factor at 60 degrees?
1.155
What are the two main types of Wire Rope Clips?
U-Bolt Type
Fist Grip Type, or J clip
What is the spacing Rule of Thumb for Wire rope clips?
the diameter of the rope x 6
Dx6
All hooks should be made from forged steel and equipped with what?
safety Latches
Cheek Weights are found where?
on Crane Blocks
What is fleet angle?
Fleet angle is the off center angle from the outside wire rope wrap on a drum to the working sheave.
What is the safety factor of Chain Falls / Come- Alongs?
