2.—(1) These Regulations shall apply below ground to all mines.
(2) Where the number of persons working in any—
(a)shaft which is in the course of being sunk;
(b)outlet which is in the course of being driven;
(c)inset; or
(d)exploratory development work from such a shaft, outlet or inset,
does not at any one time exceed 30, regulations 3, 5 and 7 shall not apply in relation to the exit or access to exits of such persons.
(3) For the purpose of paragraph (2) “inset” means a heading, chamber or other space in the course of being driven or excavated from a shaft or outlet and which is accessible only from a shaft or outlet and is not being driven or excavated solely or mainly for the purpose of getting of minerals or products of minerals.