Technical issues with battery equipped passenger rolling stock manufactured by Alstom.

[John R]

In addition, the current problems emerging with Alstom's new fleet for the Dublin LUAS, some of which may be subject to legal proceedings, and in particular the battery performance and longevity have given food for thought. It appears that the battery supplier for their BEMUs has been unable to provide a product that meets the specifications, and current concerns over said battery supplier potentially being involved in this tender have led to a pause while more information is gathered about the issue, and how it can be avoided.

Mods note - split from this thread:

ScotRail Suburban Fleet (EMU and BEMU) Market Engagement

ScotRail Trains Limited (SRT) Market Engagement Notice SRT is launching a market engagement exercise in relation to its proposed procurement for the replacement of some of its aging Diesel and Electric Multiple Units with a new fleet of Electric Multiple Units (EMUs) and Battery Electric...

www.railforums.co.uk

Is there anything in the public domain about this issue? I had a quick search, but couldn't find anything.

 

[waverley47]

Is there anything in the public domain about this issue? I had a quick search, but couldn't find anything.

Regards the Dublin issue, which is most definitely the DART and not the LUAS, my mistake, I think most of the information is coming out of the inquiry that's ongoing. There have been sporadic press releases, however I am definitely not on top of everything that's been said, and no doubt there is more information somewhere.

 

[John R]

Regards the Dublin issue, which is most definitely the DART and not the LUAS, my mistake, I think most of the information is coming out of the inquiry that's ongoing. There have been sporadic press releases, however I am definitely not on top of everything that's been said, and no doubt there is more information somewhere.

Thanks, and also for the update on the procurement.

 

[Chris125]

Is there anything in the public domain about this issue? I had a quick search, but couldn't find anything.

Experience in Australia led to a redesign of the battery packs, now completed but requiring re-approval by the European Rail Agency: https://irishcycle.com/2025/10/22/e...g-battery-electric-trains-delayed-until-2027/

“While these battery packs have been in use for almost one year during testing with no major issues or concerns, OP Mobility are currently also building train and tram traction battery systems for Alstom and Siemens across at least 5 international projects, including projects in Australia and New Zealand. The battery proposed for the Australian tram project is smaller than the battery used on the Dart+ battery electric multiple unit train, but is otherwise technically the same. During testing on the Australian tram project, this battery did not pass the required tests and needed some redesign.”

He said: “Arising from their experience on the Australia tram project, Alstom and OP Mobility advised us of the requirement to redesign the Dart+ battery-electric train battery design arrangements in order to improve the resilience of the battery packs.”

“This was notified to Iarnrod Éireann in August 2025, and this redesign is now complete. However, the formal certification tests for the Dart+ battery-electric battery must be repeated due to the design change,” he said.

Kenny added: “This means that the application for approval of the battery-electric trainset to the European Rail Agency (ERA) has moved to August 2026. While it may be the case that ERA completes its decision process sooner, IÉ must be prudent in forecasting, and has based an eight-month timeline for ERA decision on typical experience of ERA processes with other fleets in Europe.”

Surprising this could impact the Scotrail procurement, it looks like a specific technical - temperature management? - issue with that product they've already addressed.

 

[berneyarms]

Regards the Dublin issue, which is most definitely the DART and not the LUAS, my mistake, I think most of the information is coming out of the inquiry that's ongoing. There have been sporadic press releases, however I am definitely not on top of everything that's been said, and no doubt there is more information somewhere.

It came into the public domain from a statement by the new Iarnród Éireann CEO, Mary Considine, to an Oireachtas (Irish Parliament) Transport Committee hearing yesterday.

Alstom have had issues with their battery provider, and the BEMU introduction is now pushed back to Q2 2027.