21. Minimum widths: Platforms and gangways used for carrying molten metal shall have the following minimum widths:(a) 900 mm for crucibles carried by not more than 2 workmen;
(b) 1.2 m for crucibles carried by more than 2 workmen;
(c) 1.8 m if the manual transport of the crucible is done simultaneously in both directions; and
(d) 600 mm wider than the extreme width of the truck in which the ladles are transported.