Luftbremser

Luftbremser, or air brakes, are a braking system that uses compressed air to apply braking force. They are widely used on heavy road vehicles such as trucks and buses, as well as on railway rolling stock and some trams. The system stores compressed air in reservoirs and uses controlled air pressure to actuate brake mechanisms at each wheel, providing reliable stopping power and fail-safe operation in varied conditions.

Key components of a luftbremse system include an air compressor, air storage tanks (reservoirs), an air dryer to remove moisture, and a network of pipes. The service brake valve or pedal valve modulates the air pressure sent to brake chambers at each wheel. Relay valves or other control valves manage the distribution of pressure to the appropriate wheels. Brake chambers convert the pneumatic pressure into linear motion, moving pistons that push brake shoes against discs or drums. In railway applications, similar principles operate along the train, coordinated to provide braking across multiple cars.

Operation involves the driver applying the brake, which pressurizes air to the brake chambers. The resulting piston movement actuates the braking components, increasing friction on the wheels. Releasing the brake vents or reduces pressure, and springs or other mechanisms retract the shoes or pads. Emergency braking can be triggered by a rapid loss of air pressure or a dedicated emergency valve, which typically activates a prompt and stronger brake response.

Two common configurations exist: road-vehicle air brake systems with separate primary and secondary circuits for tractors and trailers, and railway systems where locomotive and car brakes are supplied through a continuous air line. Maintenance emphasizes leak detection, moisture management, and regular checks of pressure levels and valve operation to ensure safety and reliability. The luftbremse concept originated in the late 19th century and became standard in many mass-transit and commercial-vehicle applications, often complemented by electronic control and anti-lock features.