Clause 27

No traversing part of any self-acting machine and no material carried thereon shall, if the space over which it runs is a space over which any person is liable to pass, whether in the course of his employment or otherwise, be allowed on its outward or inward traverse to run within a distance of five hundred millimetres from any fixed structure not being part of the machine.

All practicable steps shall be taken by instructions to the person in charge of the machine and otherwise to ensure that no person employed shall be in the space between any traversing part of a self-acting machine and any fixed part of the machine towards which the traversing part moves on the inward run, except when the machine is stopped with the traversing part on the outward run.