When a train passes on curves without super-elevation, which rail does it exert thrust on?

When a train passes through a curve without super-elevation, it tends to exert thrust on the inner side of the outer rail. This phenomenon occurs due to the combination of centrifugal force acting on the train and the weight distribution across the wheels.

As the train travels along a curved path, the centrifugal force pushes the train outward, away from the center of the curve. However, the weight of the train primarily presses down on the inner rail due to the angle created by the train's position on the curve. As a result, the wheels on the outer rail experience a lateral force that can be perceived as a thrust directed toward the inner side of the outer rail.

This interplay of forces is critical in understanding how trains behave on curves, especially in relation to rail design and track maintenance. Properly managing these forces is essential to ensure stability and reduce wear on tracks, which is fundamental for safe rail operations.