Railway Flashcards

What is 'creep' in railway track terminology?

Answer: Longitudinal movement of rails due to traffic

Rail creep is the longitudinal movement of rails in the direction of traffic caused by temperature changes and braking/traction forces.

Which component of a railway turnout (switch) guides the wheel from one track to another?

Answer: Tongue rail (switch rail)

The tongue rail (switch rail) is the movable tapered rail that deflects wheel flanges from one track to another.

What is the 'virtual transition' concept in railway engineering?

Answer: Gradual change in curvature introduced by speed restriction

A virtual transition is a speed restriction that simulates the effect of a physical transition curve where space is insufficient.

The 'equilibrium speed' on a superelevated curve is the speed at which:

Answer: No lateral force acts on either rail

At equilibrium speed, centrifugal force exactly balances the component of gravity due to superelevation, resulting in no net lateral rail force.

What is the purpose of a 'check rail' installed near frogs in railway crossings?

Answer: Prevent wheel from taking the wrong route at the frog gap

Check rails guide the wheel flange and prevent it from taking the wrong route through the gap (flangeway) at the frog point.

In railway design, what does 'AREMA' stand for?

Answer: American Railway Engineering and Maintenance-of-Way Association

AREMA (American Railway Engineering and Maintenance-of-Way Association) publishes the primary design standards for US railways.

Which track geometry parameter measures the difference in elevation between the two rails at a cross-section?

Answer: Cross-level

Cross-level (also called cant or superelevation) measures the height difference between the two rails at any given cross-section of track.