You are lifting a 3-ton weight with a single whip rove on a swinging boom set at an angle 20° 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.

Question

You are lifting a 3-ton weight with a single whip rove on a swinging boom set at an angle 20&deg; 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.

Accepted Answer

Option A: 1 3/8 inch. Lowering the boom angle to 20 degrees significantly increases the stress vector on rigging attachments due to mechanical advantage geometry. Applying standard shackle sizing formulas for this 3-ton lift requires a minimum 1 3/8 inch shackle.

You are lifting a 3-ton weight with a single whip rove on a swinging boom set at an angle 20&deg; 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.

You are lifting a 3-ton weight with a single whip rove on a swinging boom set at an angle 20° 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.