Single-line track creep due to directional traffic loading On a single-line railway, 10 goods trains loaded with iron ore run daily from station A to station B, and the empty wagons return from B to A. In which direction will the cumulative rail creep be greater, considering traction and braking effects under unequal loading?

Introduction / Context:
Rail creep is the gradual longitudinal movement of rails in the direction of dominant traffic and tractive/braking forces. On single-line mineral routes, loaded trains in one direction and empties returning in the opposite direction produce asymmetric forces that bias creep. Understanding this helps plan creep anchors, anti-creep devices, and maintenance schedules.

Given Data / Assumptions:

• Ten loaded goods trains run daily from A to B.
• Empty wagons return from B to A each day.
• Same alignment, similar speeds, but vastly different trailing loads.
• Track has conventional fastenings with typical longitudinal restraint.

Concept / Approach:
Creep is influenced by (a) traction at rail-wheel contact, (b) braking forces, (c) thermal expansion moderated by resistance, and (d) unbalanced traffic tonnage. Heavier trains develop larger tangential forces at contact, so the net daily “push” on the rail aligns with the direction of loaded movement. Braking in station approaches or gradients amplifies the effect in that same direction.

Step-by-Step Solution:
Compare effective tonnage: loaded A → B is much greater than empty B → A.Heavier trains create higher longitudinal forces during acceleration and braking.Daily net force bias therefore points from A toward B.Hence cumulative creep becomes greater in the A → B direction.

Verification / Alternative check:
Permanent-way records on mineral lines show anchor marks and sleeper screw elongation patterns consistent with the loaded direction. Anti-creep devices are often concentrated on the downstream side of expansion gaps in the loaded direction.

Why Other Options Are Wrong:
Zero: Ignores directional load asymmetry, which is the main driver of creep.More in B → A: This would require heavier traffic or braking bias in the opposite direction, which is not the case.None of these: A clear direction can be identified (A → B).

Common Pitfalls:

• Assuming equal creep in both directions with equal train counts; mass, not just count, matters.
• Confusing thermal rail movements with traffic-induced creep.
• Ignoring station location and braking zones, which usually reinforce the loaded direction bias.

Final Answer:
more in the direction A to B