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Dropped object – wireless crane control unit

What happened?

A dropped object event occurred when a crane wireless remote control unit fell from the main deck to the ROV winch room deck below. An operator was controlling a 3 tonne crane with a wireless remote control unit (1.5kg) strapped to his waist. As the operator stood at the edge of the hatch to view the crane hook, the belt buckle failed, and the remote-control unit dropped almost 7 m to the ROV winch room deck below.

Two riggers assisting the crane operator were in the ROV winch room. Both were correctly positioned well outside the DROPS exclusion zone.

What were the causes? What went wrong?

The wireless remote controller was secured around the waist of the crane operator by a belt with a plastic side release buckle clip (securing mechanism). The original manufacturer’s securing mechanism was used. Given the age of the crane, it was estimated that the belt was approximately 10 years old. The service logs did not indicate any changes, replacement or repairs to the remote unit or the belt.

For six months prior to the incident the remote control unit was stored in a dry store without direct sunlight. It could not be determined where it was stored before that.


  • Include inspection and replacement of securing mechanisms within PMS (planned maintenance systems);
  • Inspect securing mechanisms of wireless remote-control units and consider the use of a secondary retention strap such as a DROPS lanyard;
  • Review the application of kick boards around hatches and areas with the potential for dropped objects;
  • Reinforce the importance of pre-use visual inspections of equipment.

Safety Event

Published: 9 October 2020
Download: IMCA SF 29/20

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