03/25/2022 Liebherr on-board in new air-free Siemens Brake System
Liebherr has been selected by rolling stock manufacturer Siemens Mobility for a joint development and the delivery of a key component of their new air-free Siemens Brake System: the electro-hydraulic brake actuator, which provides the brake force for the brake system. Unlike the conventional pneumatic brake, with the new air-free Siemens Brake System the control of the brake is fully electrical – “brake-by-wire” –, which means that all piping and all pneumatic components for controlling the brake can be eliminated.
In close collaboration with Siemens Liebherr developed and produces a compact, closed, electrohydraulic brake actuator including all the components necessary to build-up and release the brake force as well as local control. The brake actuator is integrated in the bogie in the same installation space and has the same mechanical interfaces as the conventional pneumatic brake caliper. This brake actuator meets the highest safety requirements and Safety Integrity Levels up to SIL4 and also the latest rules and regulations for safety verification. The brake actuator is derived from the technology that Liebherr developed for aerospace flight control actuation applications.
As Mr. Jens Lichterfeld, Senior Expert Brakes at Siemens Mobility puts it: “Using the air-free brake results in a number of benefits on car-level, including reduced weight and reduced effort for installation and commissioning of the brake system. In addition, installation space that was previously required for the air brake components can now be used for other subsystems. That’s extremely useful when it comes to vehicle development". In operation, efforts can be reduced in several areas like maintenance, train’s start-up time and shortening of headways.
Siemens Mobility is implementing the new brake technology for the first time on the X-Wagen metro project in Vienna (Austria).
According to Mr. Robert Steinfelder, Vice President Siemens Brakes at Siemens Mobility: “Wiener Linien will then be the first transit authority in the world to benefit from our brake system, both in conventional operation with a driver and later in automated operation on the new U5 Line.”