1. In the case of face workings where props are used—
(a)the maximum distance between props in the same row must be 1.2 metres;
(b)the maximum distance between adjacent rows of props must be 1.2 metres;
(c)the sum of the distances between the props in the same row and between adjacent rows of props must not exceed 2.1 metres;
(d)the bars must always be used above the props where the extracted height exceeds 0.6 metres; and
(e)the maximum distance between the row of props closest to the face and the face must be—
(i)where an armoured conveyor is used and persons do not normally work on the face side of the conveyor, 2 metres; and
(ii)in all other cases when filling or loading at the face has been completed, 0.9 metres.