Functions of sleepers: Which statement below is incorrect regarding the roles of sleepers in maintaining track geometry and load distribution?
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ASleepers hold the rails at proper gauge on straights
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BSleepers provide stability to the permanent way
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CSleepers act as an elastic cushion between rails and ballast
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DSleepers transfer the load of moving trains to the ballast
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ENone of these
Answer
Correct Answer: None of these
Explanation
Introduction / Context:Sleepers (ties) perform multiple essential functions in railway track: gauge maintenance, load transfer, damping, and positional stability. This question asks you to identify the incorrect statement among typical functions attributed to sleepers.
Given Data / Assumptions:
- Standard ballast track with timber, steel, or concrete sleepers.
- Statements list widely accepted functions.
Concept / Approach:All four listed statements are true. Sleepers maintain gauge, distribute vertical and lateral loads into the ballast and subgrade, and provide an elastic interface (in conjunction with pads/ballast) that cushions dynamic forces and reduces track stiffness variations.
Step-by-Step Solution:
Check gauge function: Sleepers and fastenings keep rail spacing correct—True.Check stability: Sleepers contribute to track stability and resistance to buckling—True.Check cushioning: Sleeper/rail pads plus ballast create elastic support—True.Check load transfer: Sleepers spread wheel loads to ballast—True.Verification / Alternative check:Textbook descriptions of sleeper functions confirm all four roles; thus, no statement is incorrect, making “None of these” the correct choice.
Why Other Options Are Wrong:
- Options A–D: Each is a correct function; none can be singled out as incorrect.
Common Pitfalls:
- Assuming only ballast provides cushioning; in practice, the sleeper/fastening system and ballast together provide elasticity.
- Overlooking that sleepers also help maintain alignment and cant on curves.
Final Answer:None of these