Brake Systems & Safety Flashcards
7 cards from real LEC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Brake Systems & Safety flashcards as text
What is the primary purpose of the independent brake valve on a locomotive?
Answer: Controls only the locomotive brakes without affecting train brakes
The independent brake valve controls only the locomotive brakes independently from the automatic brake system that affects the entire train.
During a brake pipe reduction, what happens to the brake cylinder pressure in a freight car equipped with standard AB valves?
Answer: Brake cylinder pressure increases proportionally to the reduction
When brake pipe pressure is reduced, the AB control valve directs reservoir air into the brake cylinder, increasing pressure to apply the brakes.
What is the minimum brake pipe pressure reduction required to initiate a service brake application under AAR rules?
Answer: 6 psi
A minimum 6 psi reduction in brake pipe pressure is required to initiate a service brake application according to AAR standards.
Which condition would cause a 'sticking brake' on a freight car?
Answer: A broken release spring in the brake cylinder
A broken release spring in the brake cylinder prevents the piston from returning, leaving brakes applied even after the brake pipe is recharged.
What action should a locomotive engineer take when a train experiences a 'dynamiting' (emergency) brake application due to a break-in-two?
Answer: Place the automatic brake valve in emergency and protect the rear of the train
When a break-in-two occurs, the engineer must place the brake valve in emergency and follow rules to protect the rear section of the train from following traffic.
What is the function of the brake pipe equalizing reservoir on a locomotive?
Answer: Ensures accurate and consistent brake pipe pressure reductions
The equalizing reservoir works with the automatic brake valve to ensure that brake pipe reductions are precise and repeatable by equalizing pressure between it and the brake pipe.
Under FRA regulations, how long must a locomotive engineer wait after a full service brake application before making another brake pipe reduction?
Answer: Until brake cylinder pressure equalizes, typically 15-30 seconds
The engineer must allow time for the brake system to equalize and respond before making additional reductions, which typically takes 15-30 seconds depending on train length.