17. It shall be the duty of the manager of every mine in which electric shot firing apparatus is used to make and secure the efficient carrying out of arrangements to ensure that—
(a)all such apparatus is thoroughly cleaned and overhauled at intervals not exceeding three months by the manufacturer thereof or by a competent person appointed for that purpose by the manager;
(b)all multi-shot shot firing apparatus designed for firing a round of not more than six shots is tested at the surface at intervals not exceeding seven days in a manner approved by the Minister in respect of apparatus of that type;
(c)if in connection with the firing of a round of shots by means of any apparatus described in the last preceding paragraph any of the shots fails to explode after firing, that apparatus is tested at the surface in such a manner before it is again taken below ground;
(d)no apparatus described in paragraph (b) is taken or used below ground unless on the last previous test thereof it was found to be in satisfactory order; and
(e)the date of each cleaning and overhaul and the result of each test carried out in pursuance of this regulation is entered in a book provided for the purpose by the owner of the mine.