Minimum depth of ballast cushion for a Broad Gauge wooden sleeper of size 275x25x13 cm with 75cm sleeper spacing is________________?
A. 15 cm
B. 20 cm
C. 25 cm
D. 30cm
Minimum depth of ballast cushion for a Broad Gauge wooden sleeper of size 275x25x13 cm with 75cm sleeper spacing is________________?