What is an emergency brake?

• A. A device that automatically maintains constant speed during an emergency.
• B. A mechanism to apply the train brakes in an emergency but only after a delay.
• C. A system that automatically decelerates over several minutes.
• D. A brake control used to reduce speed gradually during drills.

Answer: (D)

An emergency brake is a brake control that, when activated, immediately applies the train’s brakes with maximum force to stop as quickly as possible. It’s designed for true emergencies, overriding normal control to ensure rapid deceleration and often signaling the crew and control centers that an urgent stop is required. It’s not intended for gradual deceleration, maintaining a constant speed, or use during drills. The emphasis is on getting the train to stop fast to reduce danger, rather than easing off or delaying braking.