This section describes the pivot methods that are supported in Autodesk Civil 3D.
In a straight portion of a railway, both rails have the same level along the profile grade line. When the railway enters a curve, the pivot method specifies which point (left rail, centerline, or right rail) holds the profile grade line level. The other two points are raised or lowered to accommodate the calculated cant.
Each topic contains an illustration that displays cross sections that show the two rails and the centerline in end level rail and begin full cant critical chainages. Beneath the cross sections, a profile shows the transition of the two rails and the centerline from level rail to full cant:
The following illustration describes the Low Side Rail pivot method for a single track railway.
The following illustration describes the High Side Rail pivot method for a single track railway.
The following illustration describes the Centerline pivot method for a single track railway.