Cant of rail head: How are the rail tops (treads) placed on Indian Railways to work with coned wheels?

Introduction / Context:
Rail cant complements wheel conicity to reduce flange contact, improve guidance, and distribute contact stresses. Correct cant is fundamental to track geometry.

Given Data / Assumptions:

• Standard conicity ≈ 1 in 20 on wheel treads.
• Question asks the rail-top slope arrangement.

Concept / Approach:
Rails are canted inward at 1 in 20 so that the rail head is approximately normal to the coned wheel’s running surface. This improves contact patch and steering, reducing wear and noise.

Step-by-Step Solution:
Recall standard rail cant on IR: inward 1 in 20.Select the matching option.

Verification / Alternative check:
Permanent-way manuals specify inward cant of 1:20 for most mainline tracks.

Why Other Options Are Wrong:

• Horizontal or outward cant contradicts standard practice.
• 1 in 30 inward is not the standard value paired with wheel conicity.

Common Pitfalls:
Assuming no cant; mixing inward with outward.

Final Answer:
At an inward slope of 1 in 20