Section 3 Ventilation System

301. Ventilation system

1. The main inlets and outlets of all ventilation systems are to be capable of being closed from out- side the spaces being ventilated. In addition, such openings to areas of major fire hazard are to be capable of being closed from a continuously manned control station.

2. All ventilation fans are to be capable of being stopped from outside the spaces which they serve, and from outside the spaces in which they are installed. Ventilation fans serving major fire hazard areas are to be capable of being operated from a continuously manned control station. The means provided for stopping the power ventilation to the machinery space are to be separated from the means provided for stopping ventilation of other spaces.

3. Major fire hazard areas serving as muster stations are to have separate ventilation systems and ven- tilation ducts. Ventilation ducts for major fire hazard areas are not to pass through other spaces, and ducts for ventilation of other spaces are not to pass through major fire hazard areas. Ventilation outlets from areas of major fire hazard are not to terminate within a distance of 1 m from any control station, evacuation station or external escape route. In addition, exhaust ducts from galley ranges are to be fitted with:

(1) Grease trap readily removable for cleaning unless an alternative approved grease removal system is fitted;

(2) Fire damper located in the lower end of the duct which is remotely operated, and in addition a

remotely operated fire damper located in the upper end of the duct. Class I yachts, however, need not to be equipped with remote operation of fire dampers.

(3) Fixed means for extinguishing a fire within the duct;

(4) Remote control arrangements for shutting off the exhaust fans and supply fans, for operating the fire dampers mentioned in (2) and for operating the fire-extinguishing system, which is to be

placed in a position close to the entrance to the galley. Where a multi-branch system is in- stalled, means are to be provided to close all branches exhausting through the same main duct

before an extinguishing medium is released into the system; and

(5) Suitably located hatches for inspection and cleaning.

4. Where, of necessity, a ventilation duct passes through a fire-resisting or smoke-tight division, a re- mote operated closing fire damper is to be fitted adjacent to the division. The duct between the di- vision and the damper is to be of steel or other equivalent material and insulated to the same standard as required for the fire-resisting division. Class I yachts, however, need not to be equip- ped with remote operation of fire dampers. And, ventilation ducts which passes through a fire-re- sisting or smoke tight division, may be accepted without fire/smoke dampers if the ducts have the same integrity as the division they penetrate.

5. Where ventilation systems penetrate decks, the arrangements are to be such that the effectiveness of the deck in resisting fire is not thereby impaired and precautions are to be taken to reduce the likelihood of smoke and hot gases passing from one deck space to another through the system.

6. All dampers fitted on fire-resisting or smoke-tight divisions are also to be capable of being man- ually closed from each accessible side of the division in which they are fitted, and remotely closed from the continuously manned control station.

7. Dampers in fire-resisting divisions are to be of approved type. Special care is to be put into fasten- ing arrangement of steel ducts and steel frames in aluminium and composite structures to avoid heat bridges that may threaten the integrity of the division in a fire.

8. Supply and exhaust ducts for gas turbines may be accepted without dampers, provided the integrity of the ducts are maintained throughout the spaces they penetrate. Supply ducts for gas turbines need not be fire insulated outside the machinery spaces, provided their integrity is maintained inside the machinery spaces.

9. For class I yachts, steel dampers of robust design will be accepted for ventilation outlets from areas of major fire hazard to open decks in lieu of fire dampers.

10. Ducts are to be made of non-combustible or fire restricting material. Short ducts, however, may be of combustible materials subject to the following conditions:

(1) Their cross-section does not exceed 0.02 m ;

(2) Their length does not exceed 2 m ;

(3) They may only be used at the terminal end of the ventilation system;

(4) They are not to be situated less than 600 mm from stricting division; and

(5) Their surfaces have low flame spread characteristics.

an opening in a fire-resisting or fire-re-