Fire protection on ships is provided by detection and fire-fighting equipment together with structural features which are intended to contain an outbreak of fire and the employment when required of non-combustible materials to prevent its spread.
Air supply:
An outbreak of fire requires a source of ignition, the presence of combustible material and ample oxygen. Of the three factors, oxygen is provided in large quantities in machinery spaces, accommodation, dry cargo holds and tanker pumprooms by ventilation fans. Air supply trunkings are not only a source for a supply of oxygen to feed the fire but also have potential for carrying smoke from one area to another.
Emergency stops must be fitted so that ventilation fans can be stopped from a position external to the space served. Trunkings are provided with flaps which can be used to isolate various areas as necessary. Provision should be made so that all openings which could admit air can be closed off from a safe position external to the space or from the deck.