110. An employer shall ensure that—

(a) a work positioning system is used only if—

(i) the system includes a suitable backup system for preventing or arresting a fall and

(ii) where the system includes a line as a backup system, the user is connected to it, and

(b) if not practicable to comply with paragraph (a), all reasonably practicable measures are taken to ensure that the work positioning system does not fail.