Railway Hazards and Terminology Flashcards

What is a 'rail gap' and why is it considered a serious hazard?

Answer: A break in the running rail that can cause derailment and is difficult to detect visually

A rail gap is a break or crack in the running rail that can cause a train to derail, and because it is often hard to spot, it presents a serious threat to both trains and workers.

What does 'track gauge' measure on a railway?

Answer: The distance between the inner faces of the two running rails

Track gauge is the distance measured between the inner faces of the two running rails, with standard gauge being 4 feet 8.5 inches (1,435 mm).

Which of the following best describes 'sun kink' as a railway hazard?

Answer: Lateral buckling of the rail caused by thermal expansion in hot weather

A sun kink occurs when rails expand due to high temperatures and buckle sideways, creating a potentially severe derailment risk for passing trains.

What is the hazard associated with a 'derailed vehicle' near track workers?

Answer: Risk of secondary derailment, unstable rolling stock movement, and live electrical hazards

A derailed vehicle presents multiple simultaneous hazards including further uncontrolled movement, potential live electrical contact, and risk of secondary derailments.

What is a 'TPWS' system designed to do?

Answer: Train Protection and Warning System — automatically brake a train if it passes a red signal

TPWS (Train Protection and Warning System) automatically applies emergency brakes if a train passes a signal at danger or approaches a hazard at excessive speed.

What does 'wrong-line working' mean in railway operations?

Answer: A train operating on a track it does not normally use, requiring special safety precautions

Wrong-line working occurs when a train operates on a line in the direction opposite to normal or on a track it does not usually use, typically during engineering works.

What is meant by the 'line speed' on a particular section of railway?

Answer: The maximum permitted speed for trains authorized on that section

Line speed is the maximum speed at which trains are authorized to operate on a given section of track, determined by track condition, geometry, and infrastructure.