Decarbonising Freight Locomotives

Dual fuelling of large displacement 2-stroke freight locomotive engines is not practical from a technical development perspective for G-volution today, it is also recognised that 2 stroke engines are less efficient compared to 4 stroke engines. To overcome this technical barrier, we plan to pair our dual fuel optimiser technology with a number of smaller operationally proven 4 stroke rail diesel engines - Cummins QSK19, to deliver an equivalent installed power. Currently Network Rail operate two Class 73 locomotives, which have already been repowered with two QSK19 engines and gensets each. These vehicles and the First of a Kind SBRI competition provide a unique opportunity to demonstrate dual fuelling of a freight locomotive and gather operational data including fuel consumption data, emissions data and vehicle performance data. These outputs will form the foundation for the commercialisation of a dual fuel freight locomotive repowering solution applicable to a wide range of freight locomotive classes including the commonplace Class 66 locomotives. From a technical perspective the key innovations within the project will be: the design of the fuelling and onboard fuel storage systems to minimise the space taken up on the vehicle; the configuration of the dual fuel optimiser software, to maximise the substitution of 'green' Bio LPG for diesel - based on combustion devopment and optimisation work on a QSK19 engine in a test cell; and the integration and packaging of the optimiser and fuelling systems with the existing Class 73 vehicle architecture. G-volution have already purchased a QSK19 engine and have this on site at the Helical test centre. This engine is already scheduled to be tested with dual fuel Liquid Natural Gas (LNG) for a paralell project and this project will enable further testing of the engine with LPG to determine the maximum possible fuel substitution rates under different load conditions. A key technical challenge will be retaining as much of the existing diesel tank volume as possible. Maintaining and possibly extending the operational range of the vehicle will show that dual fuelling need not come at the expense of operational flexibility. To do this we will investigate novel ways of packaging the LPG fuel tanks within the space available on the locomotive to minimise any requirement to modify and reduce the diesel fuel tank volume. A further challenge will be ensuring the design of the system meets all necessary crash worthiness and safety standards, with a particular focus on fire safety. Diesel is a relatively safe fuel with a flash point exceeding 52C, whereas LPG’s is -104C. Assuring the fire safety of the converted locomotive and associated trackside refuelling infrastructure is therefore paramount. To achieve this we will transfer proven LPG safety systems from the automotive sector modifying these for rail as appropriate, building on the experience already gained from our ongoing DMU demonstrator with Grand Central. An additional challenge, but benefit of this project will be acquiring the Network Approvals required to operate a dual fuel LPG loco on the network. This project will benefit from G-volution’s parallel project of dual fuelling a passanger DMU with LNG as there is commonality in the approval process for both fuels. The key deliverables for this project are: 1. Issue of agreed design specification for dual fuel conversion; components, layout, wiring, engine interface 2. Network Approvals for LPG as a secondary fuel 3. QSK 19 engine configured for LPG dual fuel operation, target minimum 25% LPG substitution 4. Maintain existing vehicle range post dual fuel conversion (maintain quantities of two fuels to provde vehicle range at least that of the original diesel only configuration) 5. Dual fuel operation to mimic diesel only operation in terms of power and torque delivery