Superelevation is the raised elevation of the outer rail above the inner rail at a horizontal curve. It is denoted by ‘e’.When a vehicle moves on the curve it is subjected to a centrifugal force. The centrifugal force exerts a horizontal force on the outer rail and the weight on the outer rail increases. This horizontal force and uneven load on rails will cause the derailment. This centrifugal force can be countered by introducing the centripetal force by raising the outer rail with respect to the inner rail. This raising of outer rail with respect to inner rail is known as ‘superelevation’ or ‘canting’.

Objects of Providing Superelevation:
  • To introduce centripetal force to counteract the centrifugal force to avoid derailment and reduce the side wear of rails.
  • To distribute the wheel loads equally on the two rails. This reduces the top wear of rails and results in saving of maintenance cost.
  • To ensure the comfortable ride for passengers and safe movements of goods.