Western Rail Coalition > The Trains > Power Sources
Not sure how your train will be powered? No problem…
One manufacturer, Stadler, has designed its ‘FLIRT’ multiple unit train around the possibility that train power sources may change in the future. The basic train consists of 2 or more passenger cars with a power pack in the middle that generates electricity. The passenger cars are carried on ‘Jacobs’ trucks which are placed between them, and some of the trucks have electric motors to move the train.
By having a train that runs on electricity, various sources of power generation can be incorporated in to the power pack, including diesel engines that drive generators or alternators, batteries, hydrogen fuel cells and various ‘hybrid’ combinations. The trains can also be equipped with pantographs for power collection from an overhead catenary system (OCS). The big advantage is that if there is a shift in preferred methods for providing energy, the power packs on a train fleet could be converted or replaced without greatly affecting the passenger cars.
In addition, electric motors distributed throughout the train (rather than being consolidated under a single locomotive) offer advantages in the amount of propulsion provided can be increased according to the number of cars on the train. Acceleration is fast, smooth, and just like an ‘all-wheel drive’ road vehicle, adhesion on steep gradients in bad weather is improved.
Hydrogen Fuel Cells
Hydrogen-electric multiple units (HEMUs) use one or more on-board hydrogen fuel cells to trickle charge batteries which provide power for the train. Because of this, they are quiet and, as the batteries provide the electricity to the motors, can offer performance similar to an electric or solely battery powered train. HEMUs may also be referred to as ZEMUs, a catch-all term for zero-emission multiple units.
Stadler now has one FLIRT HEMU in the U.S. as a demonstrator to prove the technology is feasible for trains. In April 2024, the unit set a Guinness World Record for the longest journey ever completed by a hydrogen train designed for passenger use, running for 1741.7 miles in 46 hours at the FRA Transportation Technology Center in Pueblo, Colorado without refueling or recharging.
The Stadler FLIRT HEMU can currently be found operating on a trial basis for the Arrow rail service in San Bernardino County, California.