17.—(1) All staging and every part thereof shall be of good construction, of suitable and sound material and of adequate strength for the purpose for which it is used and shall be properly maintained, and every upright and thwart shall be kept so fixed, secured or placed in position as to prevent, so far as is reasonably practicable, accidental displacement.
(2) All planks forming stages shall be securely fastened to prevent them from slipping unless they extend eighteen inches or more beyond the inside edge of the thwart or support on which they rest.
(3) All staging suspended on the inside of a vessel, all staging supported by brackets, all staging on the outside of a vessel at the fore and after ends and, where there is a gap in the staging caused by the inside uprights, any plank in the way of such gap, shall be erected and adjusted by staging gangs specially, though not necessarily exclusively, employed for the purpose.
(4) All staging used in connection with the operations shall be inspected before use, and thereafter at regular and frequent intervals, by a competent person.
(5) All dry dock altars and shoring sills on or from which persons perform work in connection with the operations shall be of sound construction and properly maintained.
(6) All parts of stages, all parts of footways or passageways constructed of planks, and all parts of dry dock altars or shoring sills, being parts on or from which persons perform work in connection with the operations, shall so far as is reasonably practicable, be kept clear of all substances likely to make foothold or hand-hold insecure.