LEC Locomotive Operation and Control 2

Question 1

When applying dynamic braking on a steep descending grade, the engineer should primarily monitor which parameter to avoid overheating traction motors?

Accepted Answer

Motor current amperage

Answer

Dynamic brake effectiveness and heat dissipation are monitored via motor current amperage to prevent traction motor overheating on long descending grades.

Question 2

A locomotive's independent brake is released but the automatic brake remains applied. What is the most likely cause?

Accepted Answer

Brake pipe pressure below 90 psi

Answer

When brake pipe pressure falls below approximately 90 psi, automatic brakes apply throughout the train and will not fully release until proper pressure is restored.

Question 3

Which throttle technique is recommended when starting a heavy freight train on a level track to minimize slack run-out?

Accepted Answer

Gradually increase throttle in small increments from Notch 1

Answer

Gradually increasing throttle in small increments allows coupler slack to take up progressively, reducing the risk of run-out and coupler damage.

Question 4

During cold weather operations, what is the primary reason for pre-charging the train brake system before departure?

Accepted Answer

To ensure all brake cylinders are fully charged and frozen moisture is expelled

Answer

Pre-charging ensures all brake cylinders reach full pressure and helps expel any moisture that could freeze and impair brake function in cold conditions.

Question 5

When operating in multiple unit (MU) configuration, if the lead locomotive loses its control stand, the engineer should:

Accepted Answer

Transfer control to the rear unit using the MU changeover switch

Answer

The MU changeover switch allows the engineer to transfer locomotive control to a functioning unit when the lead cab's control stand fails.

(LEC) Locomotive Engineer Certification Practice Test

(LEC) Locomotive Engineer Certification Practice Test

LEC Locomotive Operation and Control 2