WHSQ safety alert highlights risk of hoist rope failure and loads dropping from mobile and tower cranes

Workplace Health and Safety Queensland recently issued a safety alert highlighting the risk of hoist rope failure and loads dropping from mobile and tower cranes. The safety regulator says this can happen when the hoist limit is disabled or does not function correctly.

Four incidents where hook blocks have fallen due to the hoist limit not functioning correctly have been reported in the last three years.

According to WHSQ, the hoist rope broke in three tower crane incidents, dropping a heavy hook block from the crane boom. In the 2019 incident involving a hammerhead tower crane rigged with two falls of rope, the hook block and a load of scaffold stair modules fell approximately 40 metres and hit the ground close to a pedestrian and a worker.

"Any hoist limit system set up on a mobile, or tower crane should ensure two blocking cannot occur, irrespective of the hoist speed, the number of rope falls or the boom luff angle," WHSQ stated in the alert.

To prevent two blocking, crane operators must ensure all safety features provided by the crane manufacturer, including the hoist limit, remain operational and are not to be overridden for normal operation of the crane. Additionally, hoist limits should be set up in accordance with the crane manufacturer's instructions.

WHSQ urges employers, builders, workers, and crane operators to apply the principles in this alert to any crane with a hoist rope.

For more information on the above safety alert, go to the WHSQ website.