111. An employer shall ensure that—

(a) a rope access or positioning technique is used only if—

(i) it involves a system comprised of at least two separately anchored lines, of which one (known in this Regulation as “the working line”) is used as a means of access, egress and support, and the other is the safety line,

(ii) the user is provided with a suitable harness and is connected by it to the working line and the safety line,

(iii) the working line is equipped with safe means of ascent and descent and has a self-locking system to prevent the user falling should he or she lose control of his or her movements, and

(iv) the safety line is equipped with a mobile fall protection system that is connected to, and travels with, the user of the system,

(b) provision is made for a seat with appropriate accessories depending, in particular, on the duration of the job and the ergonomic constraints, and

(c) the system referred to in paragraph (a)(i) does not comprise a single line, except where—

(i) the risk assessment has demonstrated that the use of a second line would entail higher risk to employees, and

(ii) appropriate measures have been taken to ensure safety.