A bulk carrier drifting in Cook Strait while waiting for a Wellington berth. Two lashing chains washed overboard in heavy weather. A crew improvising a solution. And a web sling, inherited from a previous operator, that nobody knew existed and nobody had ever inspected.
The result was a seaman with serious head injuries, a helicopter evacuation, and a month in Wellington Hospital.
New Zealand’s Transport Accident Investigation Commission released its final report this week into the serious injury on board the Singapore-flagged bulk carrier Thor Nitnirund on 20 March 2025. What it found was not one failure but a cascade of them, every one preventable.
What happened
The Thor Nitnirund had been drifting in Cook Strait since 18 March, waiting for a berth at the Port of Wellington. Southerly winds of 25 to 40 knots and rough seas had marked the preceding days. Two cargo lashing chains, each weighing around 75 kilograms, had been washed over the ship’s side and were trailing in the water.
On the morning of 20 March, the bosun and two able seamen assembled to retrieve them. They rigged an improvised lifting system using a mooring winch, a tiger rope, and a web sling anchored to the hatch coaming at no. 2 hold. The first chain came up without difficulty. As they started on the second, the web sling failed.
The tiger rope and shackle recoiled across the deck with significant force, striking one of the able seamen in the back of the legs. He fell, struck his head on the deck, and collided with the bosun. Both crew members ended up near the ship’s bulwarks. The bosun got to his feet. The AB did not.
A rescue helicopter arrived in the early afternoon. A little later the injured AB was winched up and flown to Wellington Hospital, where he was treated for serious head injuries. A few days later he was repatriated to Thailand to continue his recovery.
The sling that should not have been there
The web sling had a rated safe working load of one tonne. TAIC commissioned independent testing of the failed sling. It broke at 2.86 tonnes, just 48 percent of its expected minimum breaking load of six tonnes.
The sling was saturated with oil and in poor overall condition. The bearing surface of the eye had been partially cut through, damage consistent with previous use on a sharp or insufficiently rounded edge under load. Some fibres were already frayed before the accident. Only the remaining clean fibres failed on the day.
The ship’s lifting gear register listed four belt slings of one-tonne capacity, recorded as good condition following an assessment on 28 February 2025. TAIC found it was very unlikely the failed sling was one of those four. It had no identification tag, no inspection record, and no entry in the register. The Commission concluded the sling had very likely been inherited from the previous operator when Thoresen Shipping acquired the vessel in 2021, remaining on board unknown, uninspected, and available for use ever since.
The bosun picked it up with no reason to know it had never been through the ship’s safety management system.
The meeting was held in the wrong room
Before work began, the crew held a toolbox meeting in the cargo office.
TAIC’s report identifies that decision as significant. A toolbox meeting held at the worksite would have given the crew the opportunity to visualise how the rigging would interact with the ship’s structure, identify potential snag points, see where the recoil arc would land if a component failed, and look at the equipment they were about to use. In the cargo office, none of that happened.
No formal risk assessment was conducted. The toolbox log recorded three separate work activities for the day in a single 20-minute session, with no remarks. The chain retrieval was a non-routine job involving powered deck machinery. It warranted its own risk assessment. It did not get one.
Standing in the wrong place
While the winch hauled the second chain, the bosun and the injured AB were standing in the bight of the lifting system, directly in the path of the tiger rope and shackle if anything let go.
Never stand in the bight of a line. It is one of the most fundamental rules of seamanship, covered in basic training and well understood across the maritime industry. Identifying and monitoring that risk is precisely what pre-task planning and active supervision exist for.
No supervisor had been assigned because the bosun was part of the work crew. Nobody stood back with an overview of the operation to identify the danger zone. Nobody challenged where the crew were standing.
The mooring winch made it worse. Mooring winches are built to handle loads up to 30 times greater than the one-tonne rating of the sling anchoring the system. If the chain snagged, the winch would keep pulling until the weakest component gave way. With an improvised system and an uninspected sling, that point came sooner than anyone expected.
The helmet that mattered
The AB was wearing a safety helmet with the chin strap properly secured. When the recoiling rope knocked him off his feet and his head struck the deck, the helmet absorbed part of the impact. The shell separated from the harness on contact. Despite that, TAIC concluded the helmet contributed to the survivability of the accident.
PPE is the last line of defence, not a substitute for eliminating hazards in the first place. The helmet reduced the consequences of a failure that proper planning should have prevented.
A pattern TAIC has seen before
This was not the first time TAIC had investigated a snap-back injury in New Zealand waters. In 2014 a crew member on the purse seine fishing vessel Captain M. J. Souza was killed when a deteriorated choker line parted under load and recoiled into his head. In 2019, a seaman was fatally injured on the bulk log carrier Coresky OL at Eastland Port, Gisborne, when a wire snapped during a cargo-securing operation.
Both cases involved equipment failures under load, inadequate safety management, and crew in positions they should not have been in. TAIC issued recommendations after both incidents. None of those lessons were present on the Thor Nitnirund.
What changed
Thoresen and Co. Bangkok moved to address the findings before the report was published. Across the fleet, the company introduced individual identification and color coding for all lifting gear; tightened inventory controls; made worksite toolbox meetings mandatory where practicable; assigned dedicated supervision for non-routine tasks; and refocused auditing on what crews actually do rather than whether forms are complete.
TAIC issued no new recommendations.
