(4)The plans maintained under clause (b) of sub-regulation (1) shall also show spot levels on the floor of the working -(a)along haulage roadways, at every roadway junction, except in roadways where tramming is done by manual means where the spot levels may be shown at points not more than 150 meters apart; and(b)in the case of headings which have been discontinued either temporarily or permanently, also at the end of such headings:Provided that where two drifts in stone or two galleries in coal pass over one another, this shall be clearly indicated on the plans, with appropriate noting, if necessary;
