Question 1

What is the minimum design factor (safety factor) for wire rope slings?

Accepted Answer

ASME B30.9 establishes a design factor of 5:1 for wire rope slings used in general hoisting applications.

Question 2

As the angle between the sling leg and the horizontal decreases (gets flatter), the stress on the sling leg:

Accepted Answer

Lower angles (flatter slings) dramatically increase the tension in the sling legs due to the trigonometry of force vectors. At 30 degrees, the tension is double the vertical load share.

Question 3

Using a choker hitch typically reduces the sling's rated capacity to approximately ___ of its vertical capacity.

Accepted Answer

The standard reduction factor for a choker hitch is 0.75 (75%) or 0.80 (80%) depending on the angle of choke, but 75% is the standard safe assumption.

Question 4

Load: 10,000 lbs. You use a 2-leg bridle sling. Each leg is at a 60-degree angle to the horizontal. What is the tension on each leg (assuming equal loading)?

Accepted Answer

Vertical share = 5,000 lbs. Load Angle Factor for 60° = 1.155. Tension = 5,000 x 1.155 = 5,775 lbs.

Question 5

Load: 10,000 lbs. You use a 2-leg bridle sling. Each leg is at a 30-degree angle to the horizontal. What is the tension on each leg?

Accepted Answer

Vertical share = 5,000 lbs. Load Angle Factor for 30° = 2.0. Tension = 5,000 x 2.0 = 10,000 lbs. (The sling must be rated for the full weight of the load!).

Question 6

Which grade of chain is the ONLY one approved for overhead lifting?

Accepted Answer

Only Alloy Steel Chain (Grade 80 or 100) is approved by ASME/OSHA for overhead lifting. Grade 70 is for transport tie-down only.

Question 7

When installing U-bolt wire rope clips (Crosby clips), the saddle must be placed on:

Accepted Answer

'Never saddle a dead horse.' The saddle goes on the live end to protect it from crushing; the U-bolt goes on the dead (short) end.

Question 8

A steel plate is 1 inch thick, 4 feet wide, and 8 feet long. Steel weighs approximately 490 lbs/cu ft (or 40.8 lbs/sq ft per inch thickness). What is the weight?

Accepted Answer

Area = 4' x 8' = 32 sq ft. Weight = 32 sq ft x 40.8 lbs/sq ft = 1,305.6 lbs.

Question 9

Synthetic web slings must be removed from service if they show:

Accepted Answer

Any chemical burns, heat damage, or cuts exposing the inner warning yarns require immediate removal from service.

Question 10

When using a shackle to hook a sling to a crane hook, how should it be oriented?

Accepted Answer

The shackle bow should rest in the crane hook saddle. Placing the pin on the hook can lead to the pin rolling or unscrewing under load, or point loading the pin.

Question 11

A 'Basket Hitch' has twice the capacity of a single leg vertical hitch ONLY if:

Accepted Answer

True double capacity (200%) is only achieved when the legs of the basket are vertical. If they are at an angle, the sling angle factor reduces the capacity.

Question 12

The minimum recommended sling angle (horizontal) is:

Accepted Answer

Most standards and manufacturers recommend 30 degrees as the absolute minimum. Below 30 degrees, tension increases exponentially and rigging becomes unstable.

Question 13

What is the 'D/d Ratio'?

Accepted Answer

D/d is the ratio of the curvature diameter (D) to the rope diameter (d). A small D/d ratio (sharp bend) permanently damages the rope and significantly reduces efficiency/capacity.

Question 14

For a wire rope sling, capacity is reduced by 50% if the D/d ratio is:

Accepted Answer

If the rope is bent around a pin the same size as itself (1:1), efficiency drops to approximately 50%. Standard efficiency (90%+) usually requires ~20:1 or better.

Question 15

Using a knot to shorten a sling reduces its capacity by approximately:

Accepted Answer

Knots are stress concentrators that reduce the working load limit of a rope/sling by approximately 50%.

Question 16

When lifting a bundle of loose pipes, which hitch is preferred to hold them tight?

Accepted Answer

A double wrap choker (two full turns around the load) grips the bundle tightly, compressing it 360 degrees to prevent loose pipes from sliding out.

Question 17

A 'spreader bar' is used to:

Accepted Answer

Spreader bars hold the slings apart, reducing the crushing force on the load and improving the sling angle (making legs vertical).

Question 18

Shoulderless eye bolts are designed for:

Accepted Answer

Eye bolts without shoulders bend/break easily under angular loading. They are rated for vertical (in-line) pulls only. Shouldered eye bolts are required for angles.

Question 19

A shackle pin must be replaced with:

Accepted Answer

Shackle pins are engineered alloys. Replacing them with standard bolts (even high strength) creates a loose fit and unknown shear strength, which is dangerous/prohibited.

Question 20

If the Center of Gravity (CG) is not directly below the hook when the load is lifted, the load will:

Accepted Answer

Gravity dictates that the CG must be vertically aligned with the suspension point. If not, the load will swing and shift until it finds this equilibrium.

Question 21

To calculate the volume of a cylindrical object:

Accepted Answer

Volume of a cylinder = Area of circle (Pi * r^2) * Length (Height).

Question 22

When inspecting a hook, it should be removed from service if the throat opening has increased by:

Accepted Answer

ASME B30.10 requires removal if the throat opening exceeds 5% of the original dimension (or 1/4 inch).

Question 23

When inspecting a hook, it should be removed if twisted more than:

Accepted Answer

ASME B30.10 limit for hook twist is 10 degrees (or 0 degrees if manufacturer specifies).

Question 24

Which type of sling is best for high heat environments (up to 400°F)?

Accepted Answer

Synthetics melt/degrade at high heat. Steel chain or wire rope with a steel core (IWRC) are required for high temperatures.

Question 25

Softeners (padding) are used to:

Accepted Answer

Sharp corners can cut synthetic slings or kink wire rope. Softeners increase the D/d ratio locally and prevent cutting.

Question 26

The weight of a 50-gallon drum of water is approximately:

Accepted Answer

Water weighs 8.34 lbs/gallon. 50 * 8.34 = 417 lbs. (Plus drum weight).

Question 27

Concrete typically weighs:

Accepted Answer

Standard reinforced concrete weighs approximately 150 lbs per cubic foot.

Question 28

When using a 4-leg bridle sling, the load is rarely distributed equally. For planning, you should assume the load is carried by:

Accepted Answer

Due to slight length variations and load stiffness, it is standard safety practice to assume only 2 legs carry the entire load (diagonally opposite legs).

Question 29

Which end of a wedge socket is the 'live' end?

Accepted Answer

In a wedge socket, the load line (live end) must pull in a straight line with the pin hole. The dead end exits at an angle.

Question 30

The 'Design Factor' for fiber core wire rope slings is 5. What does this mean?

Accepted Answer

Design factor 5:1 means the ultimate failure load is 5 times the working load limit (WLL).

Question 31

Taglines should be used to:

Accepted Answer

Taglines allow ground personnel to control rotation and prevent the load from spinning or swinging into obstacles.

Question 32

Which sling material has the best resistance to abrasion?

Accepted Answer

Alloy steel chain is the most durable against abrasion and cutting.

Question 33

A 'Turnbuckle' is used to:

Accepted Answer

Turnbuckles allow fine adjustment of length to level a load when the Center of Gravity is off-center.

Question 34

Calculate the weight of a wood beam: 12" x 12" x 20 feet long. Wood weighs approx 40 lbs/cu ft.

Accepted Answer

12"x12" = 1 sq ft. Volume = 1 sq ft x 20 ft = 20 cu ft. Weight = 20 * 40 = 800 lbs.

Question 35

When a load is tilted, the stress increases on:

Accepted Answer

The Center of Gravity shifts toward the lower side, placing more weight on the lower sling legs.

Question 36

Wire rope slings with a 'Flemish Eye' splice have a strength efficiency of approx:

Accepted Answer

Flemish eyes (mechanically spliced with a steel sleeve) retain nearly all (90-95%+) of the rope's breaking strength.

Question 37

Safety latches on hooks are:

Accepted Answer

Safety latches (mouse) are required to prevent the rigging from inadvertently slipping off the hook.

Question 38

When inspecting a shackle, you notice the pin is slightly bent. You should:

Accepted Answer

Bent components indicate overloading or fatigue. Rigging hardware cannot be repaired; it must be destroyed to prevent use.

Question 39

Custom fabricated lifting beams must be:

Accepted Answer

ASME B30.20 requires below-the-hook lifting devices to be structurally designed, proof tested (125%), and clearly marked with capacity.

Question 40

What is the area of a circle with a 2 ft diameter?

Accepted Answer

Radius = 1 ft. Area = Pi * r^2 = 3.14 * 1*1 = 3.14 sq ft.

Question 41

The letters 'WLL' on rigging hardware stand for:

Accepted Answer

Working Load Limit is the maximum allowable load for the component.

Question 42

If a wire rope sling has a 'kink', it must be:

Accepted Answer

Kinking causes permanent deformation and structural damage to the wires/core. It cannot be repaired.

Question 43

Synthetic slings are sensitive to:

Accepted Answer

Synthetics degrade in sunlight, melt in heat, and cut easily.

Question 44

For a vertical hitch, the load on the sling is:

Accepted Answer

In a direct vertical hitch, the sling carries 100% of the load tension.

Question 45

To prevent the load from sliding out of a choker hitch on a bundle of loose pipe, you should:

Accepted Answer

A double wrap ensures 360-degree contact and compression.

Rigging Practice Questions

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