Brakes… without air

Is the future of rail one without a need for air brakes? Knorr-Bremse and Siemens have both developed systems that work without air - the electromechanical EM brake and the MoComp system respectively.

The prize is a train that no longer needs a complex system of compressors, compressed air tanks and pipes, or hydraulics.

Siemens’ version, developed with Liebherr, is to be used for the first time at the end of this year in the X-Wagen metro vehicles for Vienna (see separate story). The ‘brake by wire’ system needs only a 24V power supply and a CAN interface, its supplier says.

Knorr-Bremse says that as well as helping to enable the ‘airless train’, its EM braking system’s faster response and release times over air-brakes shorten braking distances and increase track capacity, while the ‘smart diagnostics’ function promises higher vehicle availability.

Trials have involved speeds of up to 160kph (100mph) and braking forces of up to 36kN. The system is said to promise “to drive a paradigm shift in the industry”.