254 SOCIETY NAVAL ARCHITECTS AND MARINE ENGINEERS. 



than one door may be fitted in each main transverse bulkhead within the machinery space 

 for intercommunication, but where more than one separate shaft tunnel is fitted a door 

 may be cut for each tunnel. 



If a tunnel is fitted forward either for the purpose of pipes or as a communication pas- 

 sage it shall be fitted with a watertight door. 



(4) The only types of watertight doors permissible are hinged doors, sliding doors, 

 and doors of any other equivalent pattern, excluding plate doors secured only by bolts. 



A hinged door shall be fitted with lever-operated catches workable from each side of 

 the bulkhead. 



A sliding door may have a horizontal or vertical motion. If hand-operated only, the 

 door shall be capable of being operated at the door itself and also from an accessible po- 

 sition above the margin line. If operated by power, it shall be capable of being operated 

 from the bridge, and by hand at the door itself and from an accessible position above the 

 margin line. A door dropping by its own weight, and fitted with a cataract cylinder or 

 equivalent arrangement, may be considered as being operated by power, if capable of being 

 released from the bridge. 



(5) In the case of watertight bunker doors, satisfactory arrangements shall be made 

 by means of screens or otherwise, to prevent the coal from interfering with the closing of 

 the doors. 



(6) Hinged watertight doors in passenger, crew, and working spaces are only per- 

 mitted above a deck, the under side of which, at its lowest point at side, is at least 2.13 

 meters (7 feet) above the load water line, and they are not permitted in those spaces below 

 such deck. 



Hinged watertight doors of specially heavy design may be fitted above the load water 

 line in bulkheads between cargo 'tween-deck spaces. They shall be closed before the voyage 

 commences, and kept closed while at sea by an efficient closing gear. None of these doors 

 shall be fitted, even at the ends of the vessel, in a cargo 'tween-deck space in the amidship 

 region of which 'tween-deck space it would not be permissible to fit such doors. 



(7) All other watertight .doors shall be sliding doors. 



(8) (a) When the number of watertight doors in the main transverse watertight 

 bulkheads at or about the stokehold level in the machinery space exceeds five, excluding the 

 watertight doors at the entrances of tunnels, all watertight doors situated below the load 

 water line shall be capable of being simultaneously closed from a station situated on the 

 bridge, and their opening and closing shall be indicated at that station. The simultaneous 

 closing of these doors shall be preceded by a warning sound signal. 



(b) If watertight doors which have sometimes to be open at sea for the purpose of 

 trimming coal are fitted between bunkers in the 'tween decks below the bulkhead deck, 

 these shall be operated by power. The opening and closing of these doors shall be recorded 

 in the official log. 



(c) When trunkways in connection with refrigerated cargo are carried through more 

 than one main transverse watertight bulkhead, and the sills of the openings are less than 

 2.13 meters (7 feet) above the load water line, the watertight doors at such openings shall 

 be operated by power. 



(9) Portable plates on bulkheads shall not be permitted except in machinery spaces. 

 Such plates shall always be in place before the vessel leaves port, and shall not be removed 

 at sea except in case of urgent necessity. The necessary precautions shall be taken in re- 

 placing them to insure that the joint shall be perfectly watertight. 



