Training and competence
9. The operator shall ensure that a person shall not undertake any work at the quarry unless—
(a)that person is either competent to do that work or he does so under the instruction and supervision of some other person who is competent to give instruction in and to supervise the doing of that work for the purpose of training him; and
(b)a sufficient number of persons with the requisite competence to perform the tasks assigned to them are present.