LEC Brake Systems & Safety 2

Question 1

What is the primary purpose of the independent brake valve on a locomotive?

Accepted Answer

Controls only the locomotive brakes without affecting train brakes

Answer

The independent brake valve controls only the locomotive brakes independently from the automatic brake system that affects the entire train.

Question 2

During a brake pipe reduction, what happens to the brake cylinder pressure in a freight car equipped with standard AB valves?

Accepted Answer

Brake cylinder pressure increases proportionally to the reduction

Answer

When brake pipe pressure is reduced, the AB control valve directs reservoir air into the brake cylinder, increasing pressure to apply the brakes.

Question 3

What is the minimum brake pipe pressure reduction required to initiate a service brake application under AAR rules?

Accepted Answer

6 psi

Answer

A minimum 6 psi reduction in brake pipe pressure is required to initiate a service brake application according to AAR standards.

Question 4

Which condition would cause a 'sticking brake' on a freight car?

Accepted Answer

A broken release spring in the brake cylinder

Answer

A broken release spring in the brake cylinder prevents the piston from returning, leaving brakes applied even after the brake pipe is recharged.

Question 5

What action should a locomotive engineer take when a train experiences a 'dynamiting' (emergency) brake application due to a break-in-two?

Accepted Answer

Place the automatic brake valve in emergency and protect the rear of the train

Answer

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.

(LEC) Locomotive Engineer Certification Practice Test

(LEC) Locomotive Engineer Certification Practice Test

LEC Brake Systems & Safety 2