Which one of the following statement is correct regarding ballast used for railway tracks?
1
The minimum depth of ballast for B.G. section is 20 cm – 25 cm
2
The quantity of stone ballast required for one metre length of track is 0.53 m3 for B.G. section
3
For M.G. section the width of ballast is 1.83 m
4
The minimum depth of ballast for N.G. section is 10 cm