CTB Track Systems & Components Flashcards

What is the primary function of a rail joint bar (fishplate) in a track system?

Answer: To connect two rail ends mechanically and maintain vertical and horizontal alignment

Joint bars clamp the web of two adjoining rails to transfer load across the joint and keep rail ends aligned.

What is 'gauge' in the context of railroad track?

Answer: The distance between the inside faces of the two running rails, measured 5/8 inch below the top of rail

Track gauge is the distance between the inside faces of the rail heads, measured 5/8 inch below the rail top; standard gauge in the US is 4 feet 8½ inches.

A turnout (switch) consists of which three main components?

Answer: Switch points, frog, and closure rails

A turnout's three main elements are the switch (points), the closure rails connecting to the frog, and the frog where the two routes cross.

What is the purpose of a guard rail (check rail) installed at a frog?

Answer: To keep the wheel flange on the correct path and prevent it from taking the wrong route through the frog

Guard rails are placed opposite the frog point to guide the wheel flange and ensure wheels traverse the frog correctly without derailing.

Rail cant (inclination) on most North American railroads is set at:

Answer: 1 in 40 (toward the track center)

Rail is inclined at 1:40 toward the track center so the rail head matches the conical tread of the wheel for optimal contact and wear distribution.

What does the term 'superelevation' (cross-level) refer to in track geometry?

Answer: The elevation of the outer (high) rail above the inner (low) rail on a curve

Superelevation raises the outer rail on a curve to counteract centrifugal force on passing trains, improving stability and ride quality.