CTB CTB Track Systems & Components 2 — Questions and Answers
Question 1: What is a rail anchor primarily used for?
- To resist longitudinal rail movement (rail creep) caused by train braking and acceleration forces (Correct answer)
- To connect rails at joints
- To hold the tie plate to the tie
- To measure track gauge
Correct answer: To resist longitudinal rail movement (rail creep) caused by train braking and acceleration forces
Rail anchors clip onto the rail base and bear against the tie to resist longitudinal movement from train traffic forces.
Question 2: The term 'ballast section' refers to:
- The cross-sectional profile of ballast, including shoulder width, depth under ties, and side slopes (Correct answer)
- The weight class of crushed stone used
- The distance between ballast tamping operations
- The specification number in the track standards manual
Correct answer: The cross-sectional profile of ballast, including shoulder width, depth under ties, and side slopes
A ballast section defines the required geometry of ballast placement, including minimum depth under ties, shoulder width, and slope angle.
Question 3: What is the primary purpose of elastic (spring) rail clips used in concrete tie track?
- To hold the rail to the tie while allowing controlled longitudinal movement and providing electrical isolation (Correct answer)
- To splice two rails together at a joint
- To anchor the tie in the ballast
- To adjust the gauge on curves
Correct answer: To hold the rail to the tie while allowing controlled longitudinal movement and providing electrical isolation
Elastic clips apply a controlled toe load to the rail foot, securing it to the concrete tie while accommodating thermal expansion and providing vibration damping.
Question 4: A 'derail' device is installed on a track to:
- Intentionally derail unauthorized or runaway equipment to protect the main line or other assets (Correct answer)
- Guide trains through a turnout safely
- Prevent rail from moving longitudinally
- Connect two track segments at a grade crossing
Correct answer: Intentionally derail unauthorized or runaway equipment to protect the main line or other assets
A derail is a safety device that diverts wheels off the rail to stop unintended movement and protect mainline traffic or other personnel.
Question 5: What does 'cross-level' measure in track geometry inspections?
- The difference in elevation between the two rails at any given point, measured perpendicular to the track (Correct answer)
- The vertical profile of the track centerline
- The horizontal alignment deviation from the design centerline
- The depth of ballast beneath the ties
Correct answer: The difference in elevation between the two rails at any given point, measured perpendicular to the track
Cross-level is the elevation difference between the two rail tops across the track, and excessive cross-level can cause rocking or rollover of equipment.
Question 6: What is the function of a tie plate in wood-tie track construction?
- To distribute rail load over a larger tie surface area and maintain rail cant (Correct answer)
- To electrically connect the two rails in a signal circuit
- To anchor the ballast to the subgrade
- To measure vertical track profile
Correct answer: To distribute rail load over a larger tie surface area and maintain rail cant
Tie plates spread the concentrated rail load over more of the tie's bearing area and include a built-in 1:40 cant to correctly orient the rail head.
CTB CTB Track Systems & Components 2
What is a rail anchor primarily used for?