Section 128(4) in The Coal Mines Regulations, 2011
(4)Every bar set for supporting the roof of a roadway shall be set securely on props or on cogs or shall be securely fixed on the sides of the roadway in holes at least 50 centimeter deep made in the sides of the roadway and shall be made and kept tight against roof and where lagging is necessary the number of laggings shall not be less than one for every metre length of the bar and the laggings shall be made and kept tight against the roof.
