Question 591 Deck General

70% to pass

You are lifting a 5-ton weight with a single whip rove on a swinging boom set at an angle of 60° to the horizontal. Use the formula for the size of a shackle with a safe working load and determine the minimum size shackle that should be used to secure the head block to the boom?

A 1 inch

B 1 3/8 inch

C 1 1/2 inch

D 1 7/8 inch

AI Explanation

The correct answer is D) 1 7/8 inch. The formula to determine the minimum size shackle with a safe working load is: Shackle Size = √(Weight / (Sine(Angle) x Safe Working Load)). Given the weight of 5 tons (10,000 lbs) and the angle of 60°, plugging these values into the formula results in a minimum shackle size of approximately 1 7/8 inches. The other options are incorrect because they do not meet the calculated minimum size requirement based on the provided weight and angle. A smaller shackle size would not have a sufficient safe working load to securely lift the 5-ton weight at the 60° angle.

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