If the watertight bulkheads are made to use them as accommodation or machinery spaces, they are provided with water tight doors for safe access. Such opening must be cut only when necessary for the use of safe working of the ship
There are mainly 3 type of watertight doors,
Vertically Mounted Watertight doors: These are mild or cast steel doors and it can be opened vertically or horizontally (vertical sliding door and horizontal sliding door). The means of opening must not rely on gravity
Hinged Watertight Doors: Hinged watertight doors may be fitted in the watertight bulkheads in the passenger ship, above 2.2m or more above load waterline. These are generally heavy doors that when closed, seal on a packing material that is welded to the door frame with the help of a metal strip.
Automatic operating watertight Door: This system is used in case there is a fire or flooding. In such situations, a signal is sent from the bridge or engine room to an oil diverter valve. The door is operated with the help of pressurized hydraulic oil which moves the ram that controls the opening and closing of the door.
INITIAL TESTS OF WATERTIGHT DOORS AS PER SOLAS
> In passenger ships the watertight door shall be tested by water pressure to a head up to the bulkhead deck or freeboard deck.
> In cargo ships a hose test is also accepted