Three crew members were injured, two with serious burns, when a boiler blowback threw them backwards aboard a bulk carrier at Bluff, an investigation has found.

The Transport Accident Investigation Commission released its final report on Friday into the incident aboard the Malta-registered Olivia at South Port on 24 May 2025.

TAIC found safety controls were not being used when crew attempted to clean a furnace that was still hot and contained residual fuel. It also found senior engineering officers were very likely fatigued, adversely affecting their decision-making.

The vessel had arrived at Bluff on 23 April after experiencing engine and generator problems at sea. Maritime NZ required satisfactory repairs before it could leave.

All three generators needed extensive refurbishment, stretching a planned five-day port stay to more than a month.

Operator Fleet Management Limited brought in additional personnel and technical support, with engineering work continuing around the clock in 12-hour shifts.

Most resources and senior engineering expertise were concentrated on the day shift for generator repairs. The three-person night shift was assigned routine cleaning and preparation work.

On the night of 23 May, the boiler burner failed. Repeated attempts to restart it were unsuccessful, including one that caused a blowback without injuring anyone.

The engineering team then decided to clean accumulated soot from inside the boiler.

In the early hours of 24 May, the night crew used an air lance, a long tube connected to a compressed air hose, to blow away deposits.

During the usual cleaning procedure at sea, the furnace would have been left to cool for days. This time, no objective check confirmed it had reached a safe condition.

At about 2.55am, a blowback threw all three crew members backwards. Two suffered serious burns and the third sustained bruising. All were taken to hospital.

TAIC found heated soot was likely disturbed as the air lance was withdrawn, igniting residual fuel inside the furnace.

The initial burner failure was likely caused by a combination of a malfunctioning air-intake flap, a faulty ignition transformer and accumulated soot.

A telephone discussion with the chief engineer, who had been asleep, very likely hindered a shared understanding of the proposed cleaning work and the safety controls required.

Although the operator’s safety management system included controls for unplanned work and boiler maintenance, those controls were not being used.

The crew discussed tools and the cleaning sequence but did not reassess the risks of working on the failed furnace while it remained hot.

TAIC also found the system lacked guidance for managing crew during sustained periods of intensive work. The night shift lacked the capacity to plan and supervise the unexpected higher-risk task, while some senior personnel worked beyond their scheduled hours.

Fleet Management Limited has since reported issuing a company-wide safety memorandum and reviewing its risk assessment, unplanned work, fatigue and resource management procedures.

Other measures included updating protective equipment requirements, developing a boiler safety warning poster and incorporating the lessons into training for seafarers joining its fleet.

TAIC said the operator’s actions addressed both identified safety issues, so no new recommendations were needed.

The findings highlighted the need to reassess risks when familiar work takes place under changed conditions, including verifying that a furnace has cooled safely before internal cleaning begins.