Ricardo has been appointed by UK-based rolling stock owner Porterbrook to provide engineering expertise to integrate MTU’s hybrid powerpack into a converted Turbostar diesel multiple unit (DMU) train for the HybridFLEX project.

The HybridFLEX program is expected to help eliminate diesel emissions from trains in built-up areas where there is no electrification of the rail network when the HybridFLEX train operates in a “silent” mode using onboard batteries through urban areas and during station stops.

When diesel power is required for propulsion of the train, it will be provided by an engine conforming to the latest EU Stage V emissions standards (due to come into force in 2021) with ultra-low particulates and NOx. Although EU Stage V is not currently mandated for rail, Porterbrook, Ricardo, and MTU say they are committed to applying the latest technology today, reducing emissions in urban areas.

With the onboard batteries capturing the energy usually lost when slowing the train through braking—coupled with a more efficient engine and transmission—the overall CO2 emissions could be reduced by as much as 25% when the train enters service in 2020.

The initial trial period should also confirm the higher performance and capability of the hybrid systems compared to the standard variant of the Turbostar train.

Ricardo’s engineering team are performing the integration engineering and safety assessments of the bare hybrid powerpack provided by MTU for the existing Turbostar train to convert this into the HybridFLEX vehicle.

Ricardo will oversee the integration of all the mechanical, electrical, and critical controls systems, committing teams from its Rail and Automotive divisions to support the engineering tasks and relevant safety, certification, and approvals activities to ensure the safe and successful operation of the train during public trials.

“We are looking forward to supporting Porterbrook throughout the development of this innovative and important project for the industry,” said Olivier André, UK MD of Consulting, Ricardo Rail. “The UK has many diesel vehicles on its network. This is an opportunity to show they still have a viable long-term future as hybrids, featuring reduced NOx, carbon, and noise emissions as well as offering the potential for lower operating costs.”

Once the completed trial confirms the expected performance advantages of the hybrid system, Porterbrook will work with existing and future Turbostar customers to evaluate conversion of these fleets to HybridFLEX, accelerating the move away from diesel-only trains in advance of the government’s 2040 target.