Subject to subsection (3) of this section, the provisions of this Act specified in subsection (2) of this section shall apply to any work carried out in a harbour or wet dock in constructing, reconstructing, repairing, refitting, painting, finishing or breaking up a ship or in scaling, scurfing or cleaning boilers (including combustion chambers and smoke boxes) in a ship, or in cleaning oil-fuel tanks or bilges in a ship or any tank in a ship last used for oil of any description carried as cargo or any tank or hold last used for any substance so carried of a description specified in regulations of the Minister as being of a dangerous or injurious nature; and for the purposes of those provisions as so applying the ship shall be deemed to be a factory, and any person undertaking the work shall be deemed to be the occupier of a factory.

Nothing in this Act shall apply to any such work as is mentioned in subsection (1) of this section which is done by the master or crew of a ship or done on board a ship during a trial run.