Australia: Sydney has recorded six tram fires since the start of the year. All involve the same cause: auxiliary batteries mounted on the roof of the city’s Citadis X05 trams, in service since 2019.
Speaking to the Sydney Morning Herald about the most recent fire, in July, Transdev Australasia chief executive Brian Brennan said the batteries involved had only recently been fitted, as part of a replacement programme brought forward after the fires earlier in the year. He declined to name the battery manufacturer, describing the units only as lead-acid “industrial batteries also used in aviation”. Eight trams fitted with batteries from the same batch were withdrawn from service after the incident.
The earlier fires in 2026, however, involved trams that had not yet been upgraded. These ran on battery packs of 19 nickel-cadmium FNC 235 R3 cells, with a combined capacity of 4.5 kAh, supplied by Germany’s Hoppecke. The problem is not new: in 2020, a battery exploded while a tram stood in the depot after a software fault failed to detect overheating and kept the batteries on charge.
Damaged battery on Alstom Citadis X05 tram in Sydney. Source: ATSB
Sydney’s fleet of 60 five-section Citadis X05 trams was built in France and Spain between 2017 and 2018. The trams run on overhead catenary and a ground-level third rail using Alstom’s APS system. Onboard batteries are reserved for emergency movement and auxiliary power — they play no role in normal traction.
Fires of this frequency have not been reported on Alstom rolling stock elsewhere. Citadis and Flexity 2 trams also run in Melbourne, Adelaide and the Gold Coast, with production localised at Alstom’s Dandenong plant since 2023.
