Spreader Bars and Lifting Beams Flashcards

When lifting a long structural load such as a steel beam using a spreader bar, how many tag lines should be used?

Answer: Two tag lines — one at each end of the load

Two tag lines, one at each end of the load, allow the rigging crew to control both rotation and lateral swing of a long suspended load throughout the lift.

During a test lift, the rigger observes that the spreader bar is not sitting level. What is the most likely cause?

Answer: Unequal sling leg lengths or the load's centre of gravity not directly below the pick point

An unlevel spreader bar most commonly results from unequal sling leg lengths or misalignment between the crane hook, the bar's pick point, and the load's centre of gravity.

What is the generally accepted maximum angle that sling legs should form with the vertical when used with a spreader bar?

Answer: 60 degrees from vertical

The generally accepted maximum sling angle is 60 degrees from vertical; beyond this, compressive forces on the spreader bar increase rapidly and sling load factors become unfavourable.

A spreader bar is rated at 4.0 tonnes SWL. Due to the sling configuration, a deration factor of 0.75 applies. What is the maximum load that can safely be lifted?

Answer: 3.0 tonnes

Applying the deration factor: 4.0t × 0.75 = 3.0 tonnes is the maximum allowable lift weight under these sling conditions.

What is the main advantage of using a spreader bar when lifting a large-diameter thin-walled pipe?

Answer: It prevents inward compressive forces from the converging slings from crushing the pipe

A spreader bar keeps the slings from converging inward, preventing the crushing compressive forces that would otherwise be applied to the walls of a thin-walled pipe.

What must a Lift Plan include when a spreader bar is to be used in the operation?

Answer: The SWL, sling configuration and angles, estimated load weight, and load's centre of gravity

The Lift Plan must document the spreader bar's SWL, sling configuration and angles, estimated load weight, and the load's centre of gravity to confirm all parameters are within safe limits.

After completing a rigging operation using a spreader bar, what is the correct post-use procedure?

Answer: Clean the bar, inspect it for damage, and store it correctly in a designated area

Post-use care — cleaning, inspecting for damage, and correct storage — maintains equipment condition, ensures readiness for future lifts, and ensures any damage is identified promptly.