A hydrogen-powered locomotive has been trialled successfully at the Stapleford Miniature Railway in Leicestershire.
Designed and built by engineering students and staff at Birmingham University, the prototype locomotive — part of a competition led by the Institute of Mechanical Engineering — is the first of its kind to operate in the UK.
The narrow-gauge locomotive is a hybrid design, combining a hydrogen fuel cell and lead-acid batteries.
The fuel cell is used to power the permanent-magnet electric motors and to charge the batteries, with the batteries helping to meet the peak power demands when accelerating under load.
The team, led by Stephen Kent and advised by Dr Stuart Hillmansen, told The Engineer that the fuel cell is rated at 1.1kW and the four 90 amp-hour lead-acid batteries can provide a further 13kW.
‘This is more than enough for the motors installed on the locomotive, which are rated at a combined 4.4kW,’ the team said via email. ‘It is possible to run the motors at double their maximum rated current for short durations, as demonstrated at the Stapleford Miniature Railway, which can be very useful when accelerating a train from a standing start, for example. So, in effect, the locomotive can provide a peak power output of 8.8kW.’
Hydrogen provides an extension in range in comparison with battery-only operation.
More than 5,000 litres of hydrogen are stored in a solid-state metal-hydride tank at relatively low pressure, with the system typically operating at 5 bar.
This was achieved by using one of the 10 advanced hydrogen storage units successfully employed on the university’s hydrogen-powered canal boat, the Ross Barlow.
This amount of hydrogen enables the locomotive to haul a 400kg load up over 2,700m, and two additional tanks can be fitted to further extend its range.
The locomotive also features regenerative braking to capture, store and reuse braking energy, as well as adjustable air suspension and a touchscreen remote control that operates over a Wi-Fi link.
The team added that the touchscreen remote control is based on a tablet computer running Windows 7, and the locomotive’s control system is based around a National Instruments CompactRIO industrial computer.
‘The software for these was developed using LabVIEW to give us the ability to quickly develop a powerful and user-friendly control system, as well as giving us the ability to “hook up” and monitor a wide range of sensors and signals on the locomotive,’ the team said.
Looking forward, Hillmansen, from the University’s School of Electronic, Electrical and Computer Engineering, said the prototype provided an example of how hydrogen power could work for future trains on non-electrified routes.
The core concepts of a metal-hydride storage tank feeding a hydrogen fuel cell, which works in tandem with batteries to drive electric traction equipment, is a very viable model for the future, the team said.
The team added that it would be difficult to install enough power for high-speed passenger trains using current technology, but for less power-hungry applications, such as branch lines or tram services, the technology could be modified to suit.