During a test run of a hybrid, fuel-cell-powered passenger ship, the on-board lead-acid batteries overheated, resulting a fire in the battery compartment. The local fire department was able to quickly put the fire out.
The batteries had been replaced a few days prior from the battery supplier and were in the process of being tested for the first time on the river.
The batteries are charged slowly from the fuel cell and the power is made available for cast-off and driving maneuvers.
It was systematically confirmed that the fire, which was comparable to a conventional cable fire, posed no risk to the fuel cells or the hydrogen storage tanks. There was never a danger to the captain or crew, and the fire department confirmed that there was never a risk of fire spreading to the other compartments or explosion. The cause of the fire has not yet been determined since the official investigation is still underway.
All installed and certified safety and emergency systems functioned as designed.
1. The fuel cell turned off immediately after fire detection.
2. The fire suppression system was immediately initiated thereafter.
3. The physical separation of the batteries, the fuel cell, and the hydrogen tanks prevented the fire from spreading. This separation was developed from the FMEA of the ship and hybrid system.
4. No hydrogen leaked (i.e., the physical separation worked). However, direct fire contact or overheating of the hydrogen tanks would lead to a controlled automatic discharge of hydrogen outside the vessel.
5. The CO2 fire-fighting system in the battery room was activated for fire suppression. However, the hatch was left open by the battery supplier for the test run, which reduced the effectiveness of the suppression.