Operational Guide · Registers & Logbooks

# Watertight Doors and Compartment Integrity

Watertight doors left open during navigation defeat the entire logic of watertight subdivision: SOLAS Regulation II-1/22 requires them to remain closed at sea, with strictly limited operational exceptions.

watertight doors SOLAS II-1 compartmentation subdivision

## Operational Explanation

The ship's watertight subdivision into separate compartments divided by bulkheads is the primary structural defence against sinking in the event of a breach: if a single section floods, the watertight bulkheads and the doors passing through them must prevent water spreading to adjacent sections. This defence only works if the watertight doors are actually closed when needed.

Chapter II-1 Part B-2 of the SOLAS Code governs subdivision and watertight/weathertight integrity; Regulation 22 requires watertight doors to remain closed during navigation, except for temporary opening for passage, with immediate reclosure.

## Regulatory Reference

SOLAS Chapter II-1, Regulation 21 governs the periodic operational test of watertight doors, sidescuttles and valves; Regulation 22 requires watertight doors to be closed during navigation. Power-operated doors must be able to be closed simultaneously from the bridge in not more than 60 seconds with the ship upright, and remain operable up to a 15° list on either side.

## Scope of Application

All ships subject to SOLAS with transverse/longitudinal watertight bulkheads and connecting watertight doors, with the officer of the watch on the bridge responsible for maintaining remote control of the doors and tracking every unscheduled opening.

## Procedure / How to Complete It

1. Carry out the weekly operational test (passenger ships) or per the applicable frequency of watertight doors, sidescuttles and discharge valves.
2. Verify that the simultaneous closing time from the bridge is within the required 60 seconds, with the ship upright.
3. Keep watertight doors closed during navigation, except for authorised temporary opening for personnel passage.
4. Record every non-standard opening and reclosure of watertight doors in the bridge log, with time and reason.
5. Periodically check the sealing gaskets and closing mechanisms for signs of wear or corrosion.

## Practical Example

Example bridge log entry: "Watertight door bulkhead 47 opened manually at 14:20 for personnel passage to the engine room, reclosed and verified at 14:23. Weekly operational test completed as normal on Monday, simultaneous closing time 54 seconds, within limits."

## Real Cases

Investigations into historical progressive flooding incidents have repeatedly identified watertight doors left open during navigation for operational convenience (faster access between compartments) as a factor that turned localised flooding into a sinking, defeating the entire watertight subdivision logic built into the ship's design.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Watertight doors kept open during navigation for the convenience of frequent passage between compartments | Defeats the watertight subdivision in the event of sudden flooding | Always reclose immediately after passage, with no exceptions of convenience
Periodic operational test carried out only formally, without verifying the actual closing time | Malfunction of the remote closing system not detected until a real emergency | Actually time the simultaneous closing at every test, not just verify its completion
Opening not recorded in the bridge log because considered routine | Loss of traceability of which doors were open at a given moment, useful in an investigation | Systematically record every opening/reclosure, even routine ones

## PSC Observations

PSCOs may request a practical demonstration of the simultaneous closing test of watertight doors from the bridge, verifying both the closing time and the correct status indication (open/closed) on the remote control panel.

## Operational Tips

- Don't treat opening a watertight door as a trivial operation: always reclose it immediately after passage.
- Actually time the simultaneous closing test, don't just verify that it completed.
- Check the condition of the gaskets during the operational test, not just the closing mechanism.

## Checklist

- Periodic operational test of watertight doors carried out and timed
- Watertight doors kept closed during navigation except for authorised passage
- Every non-standard opening/reclosure recorded in the bridge log
- Sealing gaskets periodically checked for wear or corrosion
- Remote control panel on the bridge verified for correct status indication

## FAQ

How quickly must a power-operated watertight door close from the bridge?
In not more than 60 seconds, with the ship upright, and must remain operable up to a 15° list on either side per SOLAS II-1.
Can watertight doors remain open during navigation?
No, except for authorised temporary opening for personnel passage, with immediate reclosure afterwards; Regulation 22 requires them to remain closed during navigation.
What does the periodic operational test verify?
The functioning of watertight doors, sidescuttles and discharge/duct closing valves, including the ability to close simultaneously from the bridge within the required time.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

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