What does "compounding" the brakes refer to?

"Compounding" the brakes refers to the integration of spring brake force and service brake force, which is a key aspect of air brake systems. In this context, the term "compounding" denotes the way that different braking mechanisms work together to enhance overall braking effectiveness.

In an air brake system, the service brakes are activated through air pressure and are responsible for regular stopping. The spring brakes, on the other hand, provide a fail-safe mechanism that engages automatically when pressure is released from the system, typically when the vehicle is parked or in an emergency situation. By compounding these forces, the braking system can achieve greater stopping power and improved safety, allowing for more controlled and reliable braking performance.

Understanding this concept is crucial for anyone operating vehicles equipped with air brakes, as it emphasizes the importance of the interaction between different braking components to maintain proper function and ensure effective stop capability.