E-cars as ticking incendiary bombs on container ships

Opinions are still divided as to whether, on balance, the risk of fire with e-vehicles is actually higher than with conventionally powered cars, because surprisingly there are no exhaustive studies on this yet. However, experts agree that extinguishing the fire is in any case much more complicated than with combustion engines – and the fire’s intensity is greater – even though there is no fuel on board.

The batteries are a critical weak point

The problem is with the batteries: if the battery in an electric car is deformed, for example in an accident, the battery cells can catch fire . This starts the chemical process inside the battery. As part of the so-called “thermal runway”, it jumps from one cell to the next. Intensive cooling with enormous amounts of water is then required to extinguish the fire. Since the flow of current is interrupted, there is at least no risk of explosion, because the battery cannot ignite because the high-voltage system switches itself off automatically.

Nevertheless, the deletion process is extremely lengthy. If a lithium battery decomposes due to a technical defect, temperatures of up to 800 degrees can occur. The cell degrades, depressurizing and releasing the highly flammable electrolyte. When it comes into contact with water, highly toxic hydrofluoric acid and phosphoric acid are formed.

Apocalypse on the high seas as a constant danger

However, the situation is different when a number of e-cars are in a confined space, such as when transported overseas on container ships. Despite the automatic shutdown of the high-voltage systems, a chain reaction can occur here and the fire can spread from one car to another on board. The result would be an apocalypse as the entire ship could go down in flames.

This is another reason why many operators of freight or passenger ferries shy away from transporting e-cars because they fear the consequences of a fire on their ships – even if they have state-of-the-art fire-fighting systems on board to at least contain a fire that breaks out until the next port is reached. Jesper Maack, spokesman for the Danish shipping company Molslinjen commented: “With the spread of electric cars, it is clear that the authorities, fire protection experts and the ferry industry as well as the manufacturers of electric cars have this at the top of their agenda.”

Logisticians and freight companies fear the risk of fire

In the case of fires on board a ship, it is not possible to extinguish the fire from the outside. Efforts are therefore being made to smother the fire by depriving it of oxygen and to seal off the affected rooms. This is not possible with open vehicle decks, which is why these fires are very difficult or even impossible to extinguish. If there are still many vehicles lined up, the burning car is probably not accessible at all. If the fire cannot be controlled using the built-in sprinkler systems, the entire ship is at risk.

Although the water is pumped overboard via ditches, these gradually become clogged with debris released by the fire, causing the extinguishing water to collect on deck. The fire also spreads to neighboring vehicles. This ensures that significant amounts of hydrofluoric acid are produced in the event of a fire. Even if the fire is under control, one must expect that the entire vehicle deck would then become contaminated. There is also a risk of considerable damage if the hydrofluoric acid gets into the environment with the extinguishing water.

Catastrophic shipwrecks involving e-cars in recent years

The problem of the environmentally friendly disposal of the contaminated extinguishing water and the burned and also contaminated vehicles then arises. And finally, passengers are at risk of the highly dangerous hydrofluoric acid gas produced reaching their area of ​​the ship. German daily Welt reporter Birger Nicolai referred in this context to a risk study by the shipping insurer Allianz Global Corporate & Specialty (AGCS), which came to the conclusion that fire and explosions on board caused 18 percent of the total loss of 9,2 billion euros.

In that year, the freighter Felicity Ace sank in the Atlantic with 4 000 vehicles on board; In 2020, the car transporter Höegh Xiamen and the container ship Cosco Pacific caught fire. In all of these cases, incorrectly declared battery charges were identified as the cause or amplification of the fires. In 2021 there were 54 total losses. As the report states, this is due to the “defective manufacture of battery cells and devices, overcharging of the cells and overheating.” The danger is therefore real.