Crane failure led to fatal accident on oyster boat

DARTMOUTH, Nova Scotia — The Transportation Safety Board of Canada (TSB) has issued its investigation report (M16A0115) into the April 2016 crane failure and fatality aboard a small aquaculture vessel near Milligan’s Wharf, Prince Edward Island.

On 29 April 2016, at approximately 1035 Atlantic Daylight Time, a small aquaculture vessel, with the operator and the deckhand on board, was performing spring maintenance of oyster growing cages one nautical mile east of Milligan’s Wharf, Prince Edward Island. The operator was working over the side of the vessel, underneath the elevated boom of the crane, to untangle a securing line attached to a floating oyster cage. The crane failed when the piston rod fractured, and the boom and attached rigging struck and fatally injured the operator.

The investigation determined that the design of the crane was flawed, not allowing for full extension of the piston rod when the crane boom was fully raised. The piston rod was therefore making contact with the hose guards when extending, subjecting it to side loading and forcing it to bend. After bending on several occasions, the material was no longer able to sustain the bending stress, and the rod fractured.

The investigation determined that the crew and the company owners had not detected the design flaw within the few weeks that the crane was in service, nor was the crew conducting a thorough visual inspection of the crane before each voyage.

If there are no standards for the design and construction of lifting appliances on small fishing vessels, there is an increased risk that unsafe lifting appliances will be constructed and installed. Also, if lifting appliances installed on fishing vessels are not inspected by either Transport Canada or an authorized representative, defects in those appliances that pose a hazard may go undetected.

The investigation also found that there were no lifejackets carried on board the vessel as required by regulation. Although the absence of PFDs did not play a direct role in this occurrence, this persistent risk has been identified in other TSB investigations.