39. The operator of a distribution mast shall be guided by a signaller where the operator cannot see the tip of the flexible end hose during a manoeuvre. More than one signaller shall be present where the first signaller’s view is obstructed.
The signaller shall
(1) observe the movement of the tip of the distribution mast where it is out of the operator’s view; and
(2) communicate instructions to the operator for moving the distribution mast, using a pre-established conventional code of signals or a telecommunications system.