Trimmers and stokers

(1) No young person shall be employed on any vessel as a trimmer or stoker. (2) In any case where a trimmer or stoker is required in a place where young persons of less than eighteen years of age only are available to satisfy such requirements then young persons who are of and over sixteen years of age may be employed but so that two such young persons be engaged and employed in the place of each trimmer or stoker required.