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HELMS: A new hybrid solution

The HELMS (Hybrid Electronic Mechanical Shunter) project is our environmentally friendly hybridisation and modernisation solution for the Class 294.

With this project we are taking a completely new direction.

The previous diesel-hydraulic drive concept of the Class 294 will be replaced by an electromechanical hybrid drive with a power-split transmission, thus establishing a future-proof energy management system that retains traction characteristics such as tractive effort in the 1,000 KW power class.

In order to test this modernisation demonstrably, the technical solution will be tested on two prototypes until the end of 2020. From 2022 it will go into series production as a technical solution for diesel-hydraulic shunting locomotives.

Thanks to the new components and their interaction, diesel consumption and CO2 emissions could be reduced by 20% (in line with our sustainability efforts). In addition, temporary emission-free operation can be achieved and average noise and particle emissions can also be reduced.

In addition to the "green" benefit, the economic aspect is also taken into account. The service life is expected to be extended by at least 16 years. The two diesel engines, the frame and the bogies can continue to be used and maintenance costs can be reduced. The old diesel engine does not have to be replaced, which leads to further savings. In addition, the new hybrid locomotive offers far greater vehicle availability than the diesel version.

The previous transmission is replaced by a power-split mechanical planetary transmission that optimises power transmission and enables efficient consumption through a hybrid control system. The use of the 92 KWh Li-ion traction battery lowers the high idling ratio of the diesel engine and even enables temporary emission-free driving.

The savings compared to diesel-hydraulic technology result, amongst other things, from the improved transmission efficiency while maintaining the power of the diesel engine and the recharging of the battery during operation as well as via plugin.

In order to be able to offer an innovative hybrid solution for the 1,000 kW power class, a joint project was set up within the DB Group. DB Cargo took over the project management as operator. DB Systemtechnik is responsible for system design, hybrid control and integration engineering.

DB Fahrzeuginstandhaltung contributed its experience with retrofits and assumed responsibility for the conversion. The project is also assisted and financially supported by DB AG's CTO unit.


Two industrial partners, Toshiba and Henschel, were responsible for supplying the main components for the prototypes.


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