High Potential Near Miss: Dropped object due to contact with crane sheave

During crane operations on a vessel operating in deep water, the whip line was retrieved from approximately 2,200 meters depth to lift and deploy a hang-off sling over the vessel’s side. While lifting the sling from the deck, a Dynamic Positioning (DP) beacon (a subsea positioning aid mounted on the crane wire just above the hook socket) came into contact with the sheave protection bars. This resulted in the beacon and its holder assembly detaching and falling to the deck below.

The DP beacon weighed 4.3kg and fell 30m to the deck below. No personnel were in the immediate vicinity at the time of the incident; however, no direct controls were in place to restrict personnel access to the area. An investigation is ongoing.

	Beacon fitted to  crane hook

• No-one was hurt.
• The worksite team acted proactively by stopping the activity, implementing direct controls to prevent recurrence, and ensuring the appropriate return-to-work process was followed.

• Although no personnel were in the direct line of fire during the event, there were insufficient controls to prevent access to this area.

• The DP beacon and clamp were fitted directly to the whip line wire rather than to the swivel/block, creating an inherent risk of snagging or clash.
• There was no secondary retention attached to the DP beacon/clamp arrangement.
• Management of Change (MoC) had not been considered before attaching the beacon to the crane wire.
• This process may have required resetting the relevant crane limits to prevent any clash or contact.
• The lifting team did not adequately monitor the beacon’s position relative to the crane sheave during lifting operations.
• Although the scope was managed by our member, the equipment and personnel involved were not directly under our members’ control.