Independently Powered Electric Multiple-Unit (IPEMU), Essex – Railway Technology

This article explores the development and testing of an Independently Powered Electric Multiple-Unit (IPEMU) train in Essex, UK. The project aimed to demonstrate the feasibility and benefits of battery-powered trains for filling gaps in electrified rail networks and serving branch lines where overhead electrification is economically unviable. This initiative, a collaboration between Network Rail, the UK Department for Transport, Bombardier Transportation, Abellio Greater Anglia, and FutureRailway, sought to assess the operational performance, cost-effectiveness, and environmental impact of battery-electric technology within the context of existing rail infrastructure. The project’s success would pave the way for wider adoption of this technology, contributing to a more sustainable and efficient railway system. The ultimate goal was to evaluate the IPEMU’s potential as a solution for reducing operational costs, minimizing environmental impact, and improving overall railway performance, thereby contributing to Network Rail’s strategic objectives. The five-week trial service, commencing in January 2015, provided critical data to inform future development and deployment of similar technologies across the UK rail network.

The IPEMU Project: A Collaborative Effort

The IPEMU project represented a significant collaborative endeavor between key players in the UK rail industry. Network Rail, as the infrastructure manager, provided the majority of the funding and acted as the project’s delivery manager. The UK Department for Transport (DfT) co-funded the project through its FutureRailway innovation program, showcasing the government’s commitment to technological advancement in the rail sector. Bombardier, a leading rolling stock manufacturer, was responsible for the modification of the Class 379 EMU and the integration of the battery system. Abellio Greater Anglia, the train operating company, provided operational expertise and facilitated the trial passenger service. Finally, FutureRailway, a railway innovation body, contributed to the project’s technical oversight and knowledge sharing.

Technological Innovations and Modifications

The IPEMU project involved the innovative retrofitting of a Class 379 Electrostar EMU (Electric Multiple Unit). This involved significant modifications to accommodate the battery system. A key aspect was the conversion of a motor car (MOSL) into a battery car (BOS), requiring the removal of existing equipment such as the motor converter module, CET tank, and power bogie. The installation of six battery rafts, each comprising a battery box, batteries (initially lithium iron magnesium phosphate), battery monitoring system, isolation switch, power distribution control panel, and battery charging inverter, was a crucial element of the transformation. The train was also equipped with new power cables, a trailer bogie, and updated HMI (Human Machine Interface) and data acquisition systems. Testing involved two battery chemistries: lithium iron magnesium phosphate and sodium nickel chloride. Ultimately, the lithium iron magnesium phosphate technology proved suitable.

Rigorous Testing and Data Acquisition

The IPEMU underwent extensive testing to validate its performance and reliability. This included on-track trials at Bombardier’s Derby facility and high-speed tests at Network Rail’s Rail Innovation and Development Centre (RIDC) in Nottinghamshire. These tests simulated real-world operating conditions, encompassing intensive branch line round trips, high-speed runs, range tests, and temperature tests. The data collected during these trials, and subsequently during the five-week passenger service between Harwich International and Manningtree stations, were crucial in assessing the viability of the IPEMU technology and informing future design iterations. This data provided insights into energy consumption, battery performance under diverse conditions, and overall operational efficiency.

Project Summary and Conclusions

The IPEMU project successfully demonstrated the technical feasibility and operational viability of battery-powered trains for specific applications within the UK rail network. The trial service provided invaluable real-world data, validating the performance of lithium iron magnesium phosphate battery technology under various operational scenarios. The project findings highlighted the potential for cost savings, reduced emissions, and improved efficiency compared to diesel trains. While the initial IPEMU was a retrofitted unit, future iterations are planned as purpose-built designs to optimize energy efficiency and minimize weight. This approach will further enhance the environmental benefits and reduce overall operating costs. The data collected will be instrumental in shaping the design and deployment of future IPEMU fleets, contributing significantly to Network Rail’s goal of a 20% reduction in operational costs within five years. The success of the IPEMU project signifies a significant step towards a more sustainable and efficient rail system, paving the way for broader adoption of battery-electric technology in the UK and beyond. Further research and development will be needed to refine battery technology, improve charging infrastructure, and fully realize the potential of IPEMU technology across diverse rail networks.

Company Information:

• Network Rail: The UK’s infrastructure manager responsible for managing, maintaining, and upgrading the railway network.
• UK Department for Transport (DfT): The government department responsible for transport policy and investment in the UK.
• Bombardier Transportation: A multinational company that manufactures rail equipment, including trains and signalling systems.
• Abellio Greater Anglia: A train operating company that provides passenger services in East Anglia.
• FutureRailway: A railway innovation body focused on the advancement of rail technology.