Sometimes we can sharpen our skill and knowledge level with a series of questions which cause us to draw from our experiences with cranes and rigging. Try your hand at the following questions and see how you score. Choose the BEST answer for each question below. (Answers below)
1. Before a rigger can select the length and capacity of slings needed to lift a load, what two things must he know about the load?
a. Height, manufacturer
b. Weight, center of gravity
c. Color, designated pick points
2. A fiber core wire rope has _____ breaking strength than a wire rope with an independent wire rope core.
a. the same
3. Which of the following does not affect the capacity of a wire rope sling?
a. D/d ratio
b. Sling angle
c. Thimbles in sling's eyes
4. Which grade of chain is the only acceptable type for use in chain slings?
a. Transport G-7
b. High test G-4
c. Alloy G-8
d. Proof coil G-3
5. Using a crane scale and test lift method we discover the load's north end weighs 21,000 lbs and the south end weighs 7,000 lbs. If the load is 16 ft in length (north to south) the center-of-gravity is approximately ____ feet from the north end.
6. If a load is to be winched across a flat concrete floor, it should be placed on a skid which has ___ on its underneath side to provide the least friction.
7. The load chain of an electric hoist ____ be wrapped around a load for lifting purposes.
a. should not
c. shall not
8. What is the maximum line pull for a 5-ton snatch block?
a. 2.5 ton
b. 10 ton
c. 5 ton
9. Which angle from horizontal will produce the greatest tension in a sling leg; a 60 degree angle, a 45 degree angle or a 30 degree angle?
a. 60 degrees
b. 45 degrees
c. 30 degrees
10. Which weight in pounds most closely correlates to a cubic foot of steel?
11. Which of the following is not a removal criteria for a synthetic web sling?
a. Worn or broken stitching
b. Illegible or missing tag
c. Severe pliability
12. What is the hand signal to raise the boom of a mobile crane?
a. Thumb up, clenched fist
b. Index finger up
c. Two hands, thumbs pointing towards each other, clenched fists
13. A load rigged with the crane hook 4 ft south of the center of gravity will initially swing ___ upon lift-off.
a. Approximately 4 ft north
b. Approximately 4 ft south
c. Approximately 8 ft south
14. There are three conditions that must be present for a 3-leg sling bridle to have equally tensioned legs: All slings must be equidistant in length. All slings must be equidistant from each other. What is the third condition that must be met?
a. All slings must be fro the same manufacturer
b. All sling connection points must be equidistant to the load's center of gravity
c. All sling connection points must be on the top surface of the load
Answers to Crane & Rigging Quiz: