What is the "spring brake" feature in an air brake system?

The "spring brake" feature in an air brake system serves as a critical safety measure. It is designed to engage the brakes using a mechanical spring in situations where air pressure is lost, such as when there is a failure in the air supply system. This feature ensures that the vehicle remains safely stationary, preventing it from rolling or drifting uncontrollably.

When the air pressure dips below a certain threshold, the spring brake system activates, applying the brakes automatically. This automatic application of the brakes is essential for safety, especially in larger vehicles like trucks and buses that rely heavily on air brake systems. It provides a reliable backup braking system that protects against accidents caused by air pressure problems.

Understanding the spring brake feature is vital for operators to ensure they are prepared for emergencies that may arise due to air brake failure, making it a fundamental aspect of the operation of vehicles equipped with air brakes.