Division 4 The steps of the boarding ladder shall:

be of hardwood or other material of equivalent properties, made in one piece free of knots; the four lowest steps may be made of rubber of sufficient strength and stiffness, or of other suitable material of equivalent characteristics;

have an efficient non-slip surface;

be not less than 480 mm long, 115 mm wide, and 23 mm in thickness, excluding any non-slip device or grooving;

be equally spaced not less than 300 mm or more than 380 mm apart;

be secured in such a manner that they will remain horizontal.