Brief introduction

Marine watertight doors can protect the hull from flooding if it breaks.  The effectiveness of these arrangements is affected by a number of factors, but it is necessary to ensure that any watertight doors on the bulkheads are closed to prevent flooding of the compartments at or almost immediately after the occurrence of a rupture.

Type

Watertight doors shall be provided at the entrances and exits on the watertight bulkheads below the deck of the bulkheads of marine, and their opening and closing modes are sliding and hinged.

• Hinged watertight door

It is required that both sides of the door can be opened and closed quickly.

• Sliding watertight door

According to the sliding direction, there are two kinds of horizontal and vertical; according to the control mode, there are two kinds of manual control and power control. (The manual closing time should not exceed 90 seconds, and the power closing time should not exceed 60 seconds.)

Set requirements

• Watertight door on watertight bulkhead

Any maneuvering mechanism for power sliding watertight doors, whether power or manual, shall be capable of closing the doors if the ship is rolling to 15° on either side.

Any sliding watertight doors can be closed remotely from the cab and can be operated in situ from each side of the bulkhead. An indicator indicating whether the door is open or closed shall be installed at the control position, and a sound alarm shall be issued when the door is closed. Power, control and indicator should work in case of main power failure. Each power-operated sliding watertight door shall have an independent manual mechanical control device. The device shall be capable of opening and closing the door by hand from either side.

• Watertight doors on passenger ships

The watertight doors shall be power sliding doors that meet the relevant requirements, and when the ship is in a positive floating position, they shall be able to be closed simultaneously from the general control console of the cab within no more than 60 seconds.

The remote control position of all power sliding watertight doors can only be located in the cockpit and the manual control above the bulkhead deck in accordance with the requirements.

Each power sliding watertight door shall be vertical or horizontal, and its power system shall be separated from any other power system. The maximum net opening width should generally be limited to 1.2m. Its independent hand mechanism shall be capable of opening and closing by hand from either side of the door and of closing the door at an accessible point on the bulkhead deck by turning the full swing crank or by other action approved with the same degree of safety. When the ship is floating, the time for the door to be completely closed by the manual control device should not exceed 90s. Controls for opening and closing the door by power from both sides of the door shall be provided, and controls for closing the door by power from the main console shall be provided in the cab. An audible alarm should be set up that is different from other alarms in the area. When the door is closed by power remote control, the alarm should sound at least 5s but not more than 10s before the door begins to move, and continue to sound the alarm until the door is completely closed. In the case of manual remote control, the audible alarm can sound when the door moves. In addition, in passenger areas and areas with high ambient noise, an intermittent light signal can be added to the audible alarm on the door. When the ship is afloat, the time from the beginning of the movement of the door to the complete closing of the door shall in any case be not less than 20s or not more than 40s.

The centralized console in the cab shall be provided with a diagram indicating the position of each door, with a light-emitting indicator to show the open or closed status of each door. A red light means a door is fully open, while a green light means a door is fully closed. When the door is closed remotely, the red light should flash to indicate that the door is in the process of closing.

Watertight doors installed on watertight bulkhead walls separating cargo holds between deck spaces may be hinged, rolling or sliding but need not be remotely controlled. They should be mounted at the highest point and as far away from the outer plate as possible. The shutdown time must not meet the requirement of shutting down within 60 seconds.

• Watertight doors and hatchcovers on cargo ships

Exits and hatches, which are used to ensure the watertight integrity of internal openings and are normally closed during navigation, shall be provided there and in the cab with means of indicating whether these doors or hatches are open or closed. The use of such doors or hatches shall be subject to the approval of the operator on duty.

Well-constructed watertight doors may be installed as internal compartments for large cargo premises. These doors may be hinged, rolling or sliding but shall not be remotely operated. Such doors shall be properly closed before departure and shall remain closed during the voyage; the time when such doors are opened in port and the time when the ship is closed before departure shall be entered in the log book.

In short, I hope this article can help you better understand Marine watertight doors. If you have any questions or want to buy Marine watertight doors, please contact me.