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# Negative Cant / Super-elevation in Railways

## Negative Cant/ Super-elevation is a unique situation which occurs when the main line lies on a curve with a branch line turnout of contrary flexure

It is a contradictory situation where the inner rail is raised above the outer rail

### Super-elevation/ Cant in Railways

It is the difference in height between the outer and the inner rail on a curve. It is provided to compensate the centrifugal force which causes irregular stressing of rails and other track components

• Positive when the outer rail on a curved track is raised above the inner rail

• Negative when the inner rail is raised above the outer rail

### Negative Cant

This is a unique situation which occurs when the main line lies on a curve with a branch line turnout of contrary flexure. If the branch-out is on the same side - similar flexure, there is no problem of negative cant.

This is a contradictory case where the superelevation necessary for the average speed of trains running over the main line curve cannot be provided.

• AB -  outer rail of the main line curve - must be higher than CD.

• Branch line - CF should be higher than AE or point C should be higher than point A.

Check the image above to understand. In such cases, the branch line curve has a negative superelevation. Speeds on both tracks must be restricted, especially on the branch line

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