An accurate levelling of the track is important and consequently its faults affect the rolling stock and cause dynamic overloads on the rails, therefore checks of this and other track parameters are necessary (alignment, width, etc.) using geometric monitoring. The levelling part of the ballast renovation is carried out by raising and aligning the track with a heavy tamping machine equipped with groups of mobile tampers that raise the track to the level required. Once the first levelling has been completed, the track should be stabilised by static or dynamic compaction continued by the second and final levelling.