All railways have slopes. Under the same terrain, the slopes of domestic high-speed railways are usually greater than those of ordinary railways. Because the slopes have great influence on freight trains, ordinary railways try to adopt lower slopes. High-speed EMU has strong climbing ability.

The curve radius of high-speed railway is very large, and the route selection is far less flexible than that of ordinary railway. When encountering an obstacle, it needs to rely on a large slope to overcome it. The steep slope can reduce the length of the tunnel crossing the ridge and the height of the deep valley bridge, and it can also cross the highway village faster in the plain area.

Degree method

Gradient is expressed in degrees and calculated by trigonometric function. The formula is as follows:

Slope =tanα (inclination angle) = height difference/distance

So α (slope angle) = arc tan (slope) = arc tan (height difference/distance).

Tangent and sine slopes of different angles

Angular tangent sine

0 0% 0%; 5 9% 9%; 10 18% 17%; 30 58% 50%; 45 100% 7 1%; 60 87%; 90 ∞ 100%