Coning of wheels on railway vehicles is provided mainly to achieve which of the following?

Introduction / Context:
Railway wheel treads are given a conicity (usually about 1 in 20). This geometric feature is fundamental to the self-centering action of wheelsets and affects wear, guidance, and comfort.

Given Data / Assumptions:

• Standard two-axle bogie wheelsets with rigid axle.
• Conicity creates different rolling radii on left and right treads during lateral shifts.

Concept / Approach:
Coning produces a restoring action: when the wheelset shifts laterally, one tread runs on a slightly larger rolling radius, the other on a smaller one, creating a yaw that recenters the axle. This reduces flange strikes (protecting the inner faces of rails), guides smoothly on curves, and improves ride comfort by limiting hunting amplitude.

Step-by-Step Solution:
Relate conicity to differential rolling radius → self-steering on curves.Less flange contact → reduced rail/wheel wear and inner face damage.Smoother tracking → improved passenger comfort.Therefore, all statements are true.

Verification / Alternative check:
Vehicle dynamics models show conicity’s role in limiting lateral hunting at operational speeds and guiding on curves without heavy flange contact.

Why Other Options Are Wrong:

• Any single reason is incomplete; coning offers multiple benefits.
• “None” contradicts standard permanent-way practice.

Common Pitfalls:
Assuming conicity alone eliminates all flange contact; in tight curves or misalignments, flanges still engage.

Final Answer:
All of the above.