In July 2022, Jetty Middelkoop, Hazardous Substances Advisor at the Amsterdam-Amstelland Fire Department, was called out to a fire in the energy storage system (EOS) of a brand new river cruiser. An exciting extinguishing job, because according to her, too little is known about these systems. She shared her experience in a webinar on EOS and advocated for more information sharing. Come on board with us!
Evacuation of guests and crew
On a summer's day in July, the fire brigade received a report at 6:29 p.m. of a Swiss river cruiser docked. It would be a malfunction in one of the battery units. When the malfunction was noticed, the ship's chief of technology went to the engine room with a colleague. They didn't see any smoke. No flames either. They checked the units and then turned around and a blowtorch shot past their legs. Smoke was emitted and they heard popping noises. With an emergency corridor, they activated the emergency stop and left the room. Not much later, an explosion followed. At that moment, 112 was called and the evacuation of the 173 guests and 53 crew members started.
Initial opinion of AGS
"My colleagues who were the first on the scene and went to the bottom with respiratory protection noticed a high concentration of carbon monoxide and flammable gas in the ship's passage. They didn't know what was going on in the battery room. The door was closed. The only information they had was that a brief puff of smoke had been seen earlier from the bridge. It came from the exhaust of the battery compartment on the side of the ship. The firefighters and duty officer pulled out the fire plan to make a deployment plan. At the same time, I, the AGS, was called in for an initial recommendation," says Middelkoop.
"Not everything that looks like smoke is smoke. With lithium-ion batteries, flammable vapour is released first."
Keep the door shut!
"It turned out to be an energy storage system (EOS) with lithium-ion batteries, from a supplier I was familiar with. That was nice to hear." The officer then wanted to know what the greatest danger was. Middelkoop: "It is often thought that the release of additional toxic substances such as hydrogen fluoride is the greatest danger. But in the event of a fire, toxic substances are always released," she explains. "The biggest danger with lithium-ion batteries is if they are vaporising in an enclosed space. This creates an accumulation of flammable gases, which can lead to explosion." Her advice was: keep the door closed! "We also often hear," she continues, "that people say: there's a fire, because it smokes. This is not always the case, because lithium-ion batteries first release flammable vapour. So not everything that looks like smoke is smoke."
With Jetty on board
Middelkoop was then asked to come to the ship as a matter of urgency. At the scene, she wanted to know exactly what was going on. Was it a single battery or an entire module? That was difficult to assess, because the emergency stop had cut off all communication with the battery compartment. As a result, the ventilation could not be switched on either. "What's next? Because we only wanted to open the door when it was safe." The day ended with the conclusion that, unfortunately, no gas measurement in the battery compartment was possible. Ventilation had not worked either. However, the extinguishing system was activated manually, in case there was still flammable gas in the room. And the door? It remained closed.
"To my utter surprise, without ventilation, there was only a few ppm of carbon monoxide left in the room."
Day Two
The next day, various attempts had been made to take guest measurements. Also from the outside. But unfortunately, the exhaust, from which the puff of smoke came earlier, was dislodged so that the valves did not open. And a measurement at the battery compartment door also failed. "In the end, my colleagues broke open the door with hydraulic rescue tools. Of course I had my measuring equipment at the ready and to my utter surprise, because there was no ventilation, was there?, there were only a few parts per million (ppm) carbon monoxide left in the room. Nothing else. I still have no idea where all that flammable vapour and smoke went." The space turned out to be badly damaged and no longer usable. The ship sailed to Germany that same evening for repairs.
We still don't know enough
The cause of this incident is said to be an electrical problem in the Battery Control Unit (BCU). It came loose with a lot of energy and hit the wall on the other side of the room. Unfortunately, Middelkoop still doesn't know exactly what went wrong. The debriefing has not yet taken place. "In any case, what is crucial for the fire brigade in these types of incidents is ventilation and gas measurement. This is how we determine whether a room is safe. In the case of this fire, we also asked ourselves the question: did we do it right? And honestly? I found it quite exciting! In short, we still know far too little about fire in energy storage systems. That's why I always poke my nosy into incidents. Of ourselves and of others. And I call on the parties involved to do the same. And to share information more often, because we learn so much from that."
Photos Jetty Middelkoop, fire in EOS at Viking Gymir, July 2022.
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