47. An opening to the surface of a stope that is not filled in to the surface or closed by a slab in accordance with section 46 shall be surrounded by a fence made of:(1) galvanized steel posts no less than 90 mm (3.5 in) in diameter, forming its ends, corners and gates;
(2) intermediate galvanized steel posts not less than 60 mm (2.3 in) in diameter and spaced at intervals not exceeding 3 m (9.8 ft);
(3) an upper bar of galvanized steel having a diameter of at least 45 mm (1.7 in) and placed at a height of at least 2.5 m (8.2 ft) above the ground;
(4) a lower bar of galvanized steel having a diameter of at least 40 mm (1.6 in) and placed at a height of not more than 10 cm (3.9 in) above the ground;
(5) galvanized No. 9 AWG steel wire mesh, forming links of not more than 60 mm (2.4 in) on a side, welded to the posts and bars at intervals not exceeding 400 mm (15.7 in);
(6) 3 rows of barbed wire fixed at the top and overhanging towards the outside.