The Marine Safety Forum has issued a safety alert about an object falling from a load being repositioned by a crane onto the deck of a supply vessel.
The rig’s starboard crane was repositioning a tank on the aft deck of the vessel so it could be secured more effectively prior to the vessels departure for port, at the request of the master of the vessel involved in the incident.
While manoeuvring the lift, a piece of grating from the top of the tank fell from a height of approximately 6-7 m onto the vessel’s deck.
Two deck personnel were around 15 m away from the dropped object, which weighed 17 kg. The potential consequence of a 17 kg object falling 6 m was a fatality.
Why did it happen? What was the cause?
The tank frame had grating sections on the top of the unit to cater for personnel accessing the hatch on the top of the steel tank. The centre sections hinge to allow the hatch on the top of the tank to be opened. The outer sections of the grating should be fixed in place with four bolts and butterfly clips each.
While repositioning the lift, the bottom of the tank hit the cargo rail tilting and rocking the lift causing the grating to fall off.
On subsequent investigation it was found that only one clip was correctly fitted on one side grating and all four clips appeared slack on the side the grating fell from. One of the clips was also bent.
Corrective action taken and recommendations
The unit was returned to port and quarantined until it could be lifted safely and returned to the vendor. A replacement tank was ordered and instructions given to the vendor to ensure checks are made to the securing arrangements on all their cargo units.
The Marine Safety Forum said the safety alert should act as a warning to suppliers, vendors, logistics service providers, road transport companies, vessel and installation crews of the dangers of unsecured loose objects on cargo units and the potential for dropped objects.
“Loading and discharging cargo in an offshore environment is a very dynamic operation, often with significant vessel and crane hook motion, which may sometimes lead to a cargo unit impacting other containers or structures with associated accelerations that can potentially dislodge loose items,” the forum said.
“This incident aptly demonstrates the importance of vessel and installation crews staying well clear of suspended crane lifts at all times where there is a potential for falling objects.”