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 'wheel slide' and what automatic system on modern locomotives helps prevent it?
Answer: Loss of wheel-rail adhesion during braking, prevented by wheel slide protection (WSP) systems
Wheel slide occurs when braking force exceeds available wheel-rail adhesion, causing wheels to lock and skid; WSP systems modulate brake pressure to maintain adhesion.
Under AAR interchange rules, what is the maximum allowable brake cylinder travel for standard 10-inch freight car brake cylinders?
Answer: 7.5 inches
The maximum allowable brake cylinder piston travel for standard 10-inch freight car cylinders is 7.5 inches; exceeding this indicates worn or maladjusted brake rigging.
What is the purpose of the 'dead engine' feature on a locomotive's brake system?
Answer: Allows a dead (non-powered) locomotive to be moved without manually releasing each brake
The dead engine feature allows a non-powered locomotive being towed to have its brakes properly managed without requiring individual manual releases.
A train is descending a 1.5% grade at maximum authorized speed. The engineer makes a minimum reduction and observes no speed reduction after 60 seconds. What is the best next action?
Answer: Make an additional service reduction and reassess train speed
If a minimum reduction is insufficient to control speed on a grade, the engineer should make an additional service reduction, escalating control to match the grade demand.
What is the significance of the color coding on retainer valve handles?
Answer: There is no color coding; position labels identify retainer settings
Retainer valve handles are identified by position markings (EP, LP, HP, DE) rather than color coding, and engineers must know each position's function.
What condition is indicated when a locomotive's brake cylinder pressure fails to build above 15 psi during an emergency brake application?
Answer: A defect such as a stuck control valve, kinked hose, or brake cylinder leak
Emergency applications should produce brake cylinder pressures of 50 psi or more; failure to build pressure indicates a mechanical defect in the brake system.
Which FRA regulation defines the air brake and train handling rules locomotive engineers must follow?
Answer: 49 CFR Part 232
49 CFR Part 232 governs railroad power brakes and drawbars, establishing the requirements for brake systems, testing, and train handling.