Train Handling and Performance 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 Train Handling and Performance flashcards as text
When descending a steep grade, what is the primary purpose of making a minimum reduction before the grade?
Answer: To test brake responsiveness before heavier braking is needed
A minimum reduction before a descending grade tests brake function and establishes control before additional braking force is required.
What effect does increasing train speed have on braking distance on level track?
Answer: Braking distance increases with the square of speed
Braking distance increases with the square of speed because kinetic energy—which must be dissipated—is proportional to velocity squared.
During cold weather operations, what is the main concern with slack in a long train during initial movement?
Answer: Rapid slack run-in can cause buff forces that derail cars
In cold weather, frozen or stiff wheel bearings and brakes can cause sudden slack run-in when cars start moving, generating dangerous buff forces.
What is the correct action when a locomotive's wheel slides during dynamic braking?
Answer: Reduce dynamic brake effort to allow wheels to recover traction
Reducing dynamic brake effort decreases the retarding force, allowing slipping wheels to recover traction before increasing braking again.
Which train handling technique best prevents run-in when transitioning from upgrade to level track?
Answer: Reducing throttle gradually as lead units approach the crest
Gradually reducing throttle as lead units approach the crest prevents the train from bunching when rear cars are still being pushed uphill.
What is 'stretch braking' and when is it primarily used?
Answer: Using brakes to maintain train stretch while descending a grade
Stretch braking uses retarding force to keep train couplers in tension, preventing slack run-in on descending grades.
When a locomotive engineer receives an emergency brake application signal while operating at track speed, what is the first action?
Answer: Place the automatic brake valve in emergency position immediately
An emergency signal requires immediate placement of the automatic brake valve in emergency to achieve maximum stopping force as quickly as possible.