Interview: Sebastian Günther explains the stop-start system for locomotives.

Since 2019, Voith has been offering a stop-start system for locomotives, providing a fast and uncomplicated solution for low-emission and cost-efficient rail freight transport. The OnEfficiency.StopStart automatic stop-start system switches off the engine during long waiting times that occur during loading, unloading and due to line bottlenecks. In this way, unnecessary costs and emissions are avoided.

We talked to system engineer Sebastian Günther about how the technology works and how it interacts with the drive system and alternative fuels.

?1) When does the system switch off the engine?

The system shuts down the engine when it makes sense from a technical point of view. This applies under the following conditions: It is ensured that all state variables of the engine allow a shutdown. And the current system state of the vehicle's auxiliary equipment (such as battery and compressor) is stable enough, i.e., no power demand, and thus no need for an automatic engine start is expected within the next few minutes.

The driver is warned visually before each shutdown and can reset the shutdown sequence. Therefore, he always retains the option of deciding whether the shutdown makes sense from an operational point of view.

?2) Is the use of the stop-start system safe for the starter motor, engine, battery and other components?

Our experience with 150 appropriately equipped locomotives shows that the stop-start technology is harmless, as its use does not lead to failure of these components before the regular replacement and overhaul interval.

To ensure this, our system always prioritizes the protection of the locomotive and its components. For example, the engine is only shut down if the batteries have been sufficiently charged beforehand.

Overall, our formula for maximum protection with maximized savings is based on the fewest additional starts and the longest possible shutdown times. We have presented this concept and our system to several rail diesel engine manufacturers with positive feedback and are available for three-way discussions with them.

?3) Some locomotive operators already fuel their diesel locomotives with biofuel. Can the stop-start system still be used to save fuel?

?Of course, this is not a problem. On the contrary, it even makes sense not to burn the more expensive biofuel uselessly while idling. In this case, a stop-start system can help improve the economic balance of biofuels as well.

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Want to go green at every red light? For more information about the stop-start system please visit our website: www.voith.com/oess