How are air brakes impacted by changes in altitude?

Air brakes rely on compressed air to function effectively, and their performance can be influenced by atmospheric pressure, which decreases at higher altitudes. As altitude increases, the air pressure surrounding the brake system drops, which may lead to a reduction in the efficiency of air compression and consequently affect the braking power.

This reaction means that the air brake system may not operate as effectively at high altitudes, which is important for train operations where precise and responsive braking is essential for safety. Understanding this relationship is crucial for operators to ensure proper brake performance under varying altitude conditions.

The other options do not accurately reflect the relationship between altitude and air brake performance. For instance, air brakes do not operate identically at all altitudes, as changes in atmospheric conditions directly influence their functioning.