The formation is the earthen embankment on which the other components of the track rest. For supporting the heavy loads, the earth should be of good quality and it must be compacted well. To facilitate the quick disposal of water, the formation is sloped on either side of the centre line at 2.5 per cent (1 in 40). The formation width is 6.10 m for a single line BG and 10.82 m for a double track BG, when the track is on embankment. In cutting, the widths are 5.49 m and 10.21 m respectively. The slope of the embankment is generally 1 in 2, and the cutting slope is 1 : 1.