Catastrophic engine failure, fire, and sinking of Atlantic Destiny

During a fishing expedition in Nova Scotia, an engine management system (EMS) malfunctioned spectacularly on trawler Atlantic Destiny with 31 on board.

By now, engine technology is very well-understood, but the marine environment presents one of the most difficult contexts in which to operate them. Wave heights and heavy winds generate a variable demand on vessel propulsion, which causes engines to ramp up and down in unpredictable fashion to keep the vessel on course.

Complex EMSs have been devised to deal with this problem, changing revolutions per minute (RPM) quicker than a human hand would be able. Some of these are very effective at keeping speed constant, as well as ancillary benefits such as reducing fuel consumption.

But on 2 March 2021, trawler Atlantic Destiny’s powertrain shook itself to pieces following an EMS failure. As it transpired, it was not the first time and opened up wider issues in the Canadian shipping industry.

What happened on the fateful night?

On day 13 of its fishing trip, Atlantic Destiny was proceeding at reduced speed, with high winds and waves prompting the crew to suspend fishing operations. By 9.40pm, both of the vessel’s shaft generators – which generate electrical power using a portion of propulsive power from the main engines – had failed, causing a blackout on the vessel.

Dispatched to the engine room, the chief and second engineer were diagnosing the problem when one of them heard the high-pitched whine of an engine exceeding its safe limits. Unable to shut it down, other engineers watched helplessly from the control room as the shaft generators exploded, sending metal shards careening across the room.

This would total Atlantic Destiny. On seeing this on CCTV, the master pushed the button on the radio to send a distress call and rushed down to the engine room. Meanwhile, unable to open the engine room escape hatch from the inside, the second engineer grabbed a fire extinguisher and raced to the doorway of the engine room.

The master’s distress call had not gone through. Using the radio, the master then asked another vessel, Atlantic Preserver, to send a distress call on his behalf.

By 8.08pm, it was becoming clear to the chief engineer, second engineer and chief mate that attempts to don fire suits and fight the fire with extinguishers had not worked, and worse, sounds of sloshing water were heard throughout the engine room. They made the decision to activate the engine room’s CO2 extinguisher system. This would flush the engine with carbon dioxide, displacing the oxygen fuelling the fire.

Re-entering the engine room an hour later, the chief and second engineer attempted to close the sea bay valves which were letting seawater in, but found it was too late, as the level of water was already too high to permit the valves to be closed, and the CO2 system had made breathing difficult. Rushing to start the electric fire pump, they found that the batteries were depleted, and the pump wouldn’t start.

In the hours that followed, successive journeys by a Royal Canadian Air Force craft evacuated 27 crew, as well as airdropping three water pumps to the remaining four crewmembers, hoping this would be enough to keep the vessel afloat. But by 5.30am on 3 March, it was clear this was not working. Neither was a rescue attempt several hours later, which was called off when a rescue helicopter’s hoist cables became entangled in the ship’s rigging.

At 7.00am, coastguard vessel Cape Roger arrived at the scene, and the remaining crew were evacuated from Atlantic Destiny on a fast rescue craft. Listing hard to port, Atlantic Destiny sank beneath the waves at 10.36am.

Failures in machinery and understanding

Various failures were discovered over the course of the sinking, not least of them involving the engine room escape hatch, which, it transpired, could not be opened from the inside.

Yet the biggest failure was the vessel’s EMS, which failed to prevent the engine from over speeding, causing the shaft generators to explode. This sent hot metal fragments across the engine room, which pierced seawater piping, and caused a major fire. According to the Canadian Transport Safety Board (CTSB) report, the EMS had suffered problems previously, and in 2017, had even been responsible for another engine failure.

In the rough conditions, unable to keep up with the rapid peaks and troughs in propeller load, the EMS continued to increase the fuel into the engine until disaster struck. Two independent systems, meant to conduct an emergency shutdown of the engine in such a scenario, failed to do so. Even when the engineer pressed the manual shutoff, the engine did not stop.

Another lapse was identified in fire training, which the CTSB report determined was caused by a lack of understanding among the crew. Several times after the CO2 system had been used, engineers went back and forth into the engine room, letting more air in and continuing the duration of the fire, thus defeating the purpose of the CO2 extinguisher.

Recommendations as Canada looks at the bigger picture

On the vessels that remain in its fleet, operator Ocean Choice International (OCI) has conducted considerable revisions to its safety procedures.

Following the report, Canada identified a knowledge gap in fire suppression training, when it came to the crew understanding of CO2 fire suppression systems. Re-entering the engine room within 40 minutes of the system’s activation, Atlantic Destiny crew were “unaware of the need to wait for the space to cool before re-entering”.

The report references another case, on bulk carrier Tecumseh, wherein crew re-entered the engine room shortly after the system had been activated, causing the fire to reignite. “A lack of understanding of the requirements for using CO2 fixed fire suppression systems has been a factor in several other occurrences in Canada,” the CTSB concluded.

Image: fishing equipment in Nova Scotia, Canada; credit: Shutterstock.