Rail joints: identify the incorrect requirement Which of the following statements about rail joints is incorrect, given thermal expansion needs and practical joint design for jointed track?

Introduction / Context:
Rail joints in jointed track must accommodate expansion, maintain alignment, and transmit forces. Good joints aim to be as strong and elastic as practicable, but cannot be solidly butted due to temperature-induced expansion and the need for a controlled gap.

Given Data / Assumptions:

• Conventional fish-plated jointed track considered.
• Allowance for expansion gaps at joints is standard practice.
• Joints must provide continuity in guidance and load transfer.

Concept / Approach:
Thermal movement requires a gap at joints. Proper alignment and adequate strength are goals, and some elasticity is useful to distribute impact loads. A statement claiming rail ends “butt against” is incorrect because there should be a measured expansion gap to prevent rail buckling and end batter.

Step-by-Step Solution:
Check each requirement against standard practice.True alignment? Yes, to minimize impact.Strength and elasticity? Desirable for service life.Butting ends? Incorrect—gaps are required.

Verification / Alternative check:
Track codes specify temperature-based gap charts; inspection ensures correct gap, lubrication, and fishplate integrity.

Why Other Options Are Wrong:
Options (a), (b), (c) are correct practices; only the butting-ends proposition is wrong.

Common Pitfalls:

• Setting too small a gap leading to rail expansion jams and buckling.
• Excess gap causing joint impact and end batter.

Final Answer:
Ends of adjoining rails butt against to give a continuity