Fire protection for electric buses

Development of a guideline for Hamburger HOCHBAHN

Hamburger HOCHBAHN AG operates a large part of the city of Hamburg's bus system. In addition to diesel buses, around 120 electric vehicles are currently in use. By the beginning of the 2030s, the entire fleet of around 1,100 buses will be gradually converted to emission-free drives. The vehicles will be parked at bus depots when they are not in use. The battery buses are also charged there. Nine bus depots are currently in operation across Hamburg. In Veddel, a bus depot with several levels on top of each other for parking and maintenance is also planned as a new building.

In order to ensure that the conversion of the depots meets the fire protection requirements of electrically powered buses, HOCHBAHN commissioned STUVAtec to draw up a guideline. This includes, in particular, the presentation of the fundamentals of lithium batteries and the associated fire hazards, the definition of the protection objectives taking into account the subsystems, but also extensive research into e-bus fires, the determination of necessary fire protection measures on the basis of relevant regulations and the identification of significant hazards including a risk assessment using a qualitative risk analysis. Based on this preliminary work, STUVAtec developed recommendations for fire protection measures for fire prevention, fire detection and firefighting and summarized them in a guideline.