Minimum depth of ballast cushion for a Broad Gauge wooden sleeper of size 275x25x13 cm with 75cm sleeper spacing is________________? January 18, 2019 – by admin 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 cmC. 25 cm D. 30cm