1. CE2303 Railway Engineering
Coning of Wheels
CE2303 Railway Engineering

2. Coning of Wheels
The tread of the wheels of a railway vehicle is not made flat, but sloped (1 in 20) like a cone in order to enable the vehicle to move smoothly on curves as well as on straight tracks.

3. Rail Wheel Tread

4. Rail Wheel Tread

5. Rail Wheel Tread

6. Coning of Wheels
The problem arises in the case of a curve, when the outer wheel has to negotiate more distance on the curve as compared to the inner wheel.

7. Outer Rail distance on the curve
Outer Wheel
Inner Wheel

8. Coning of Wheels
Due to the action of centrifugal force on a curve, the vehicle tend to move out.

9. The wheels of a railway vehicle are connected by an axle, which in turn fixed on a rigid frame as shown below.

10. Due to rigidity of the frame, rear axle has a tendency to move inward, which does not permit the leading axle to take full advantage of coning as shown below.

11. The rigidity of the frame, however, helps to bring the vehicle back into central alignment and thus works as a balancing factor.