Emergency Stops and Shutdowns on Ships: SOLAS Requirements and How They Work

The means provided for stopping machinery-space ventilation must also be entirely separate from the means used to stop ventilation in other spaces.

Stopping Pumps and Oil Equipment

SOLAS II-2/5.2.2.3 requires means of control for stopping specified machinery associated with fire growth, including:

• forced and induced draught fans;
• fuel-oil transfer pumps;
• fuel-oil unit pumps;
• lubricating-oil service pumps;
• thermal-oil circulating pumps; and
• oil separators (purifiers).

This distinction is important. SOLAS does not simply require an emergency-stop button for every pump or every machine onboard. Regulation 5 identifies particular equipment for which stopping controls are required.

Location of the Controls

SOLAS II-2/5.2.2.4 requires the controls addressed by Regulations 5.2.2.1 to 5.2.2.3, together with the remote controls required by SOLAS II-2/4.2.2.3.4, to be located outside the space concerned so that they are not cut off if a fire occurs within that space.

This allows essential fire-control actions to be taken from a safer location.

How Does an Emergency Stop Work?

The exact arrangement depends on the ship’s design and approved system.

In a typical installation, operating the emergency-stop control sends a shutdown command to the relevant pump, fan or other equipment.

The basic principle is:

Emergency stop activated → Equipment stops → Fuel, oil or airflow is reduced

SOLAS specifies the required stopping capability and location of the controls rather than prescribing one universal emergency-stop mechanism.

Emergency Stops and Quick-Closing Valves

Emergency stops and quick-closing valves perform different but complementary functions.

An emergency stop stops machinery such as a fuel-oil pump or ventilation fan.

A quick-closing valve isolates the fuel supply directly from an applicable fuel-oil tank. Its principal requirement is addressed separately under SOLAS II-2/4.2.2.3.4.

For example:

Stop fuel pump → Stop pumping fuel → Close quick-closing valve → Isolate fuel at the tank

This distinction is important when responding to a machinery-space fire.

Learn more about Quick-Closing Valves on Ships: SOLAS Requirements.

Ventilation Shutdown and Closures

Stopping ventilation fans alone does not necessarily isolate the affected space.

Under SOLAS II-2/5.2.1.1, the main ventilation inlets and outlets must be capable of being closed from outside the spaces being ventilated. The closing arrangements must be readily accessible, permanently marked and indicate whether the shut-off is open or closed.

For machinery spaces, SOLAS also addresses controls for openings such as skylights, funnel openings that normally permit exhaust ventilation and ventilator dampers.

Therefore, an important fire-control sequence may involve:

Stop ventilation → Close ventilation openings → Isolate the affected space

These actions are particularly important when preparing a machinery space for the use of a fixed fire-extinguishing system.

Testing and Maintenance

Emergency stops must work when they are needed.

Routine inspection and testing should verify that controls are clearly identified, accessible and capable of stopping the intended equipment. Associated control circuits and shutdown arrangements should also be maintained in accordance with the ship's procedures and approved arrangements.

Crew members should know where the emergency shutdown controls are located and exactly what equipment each control stops.

Testing must follow the vessel's procedures because unintentionally stopping fuel, lubrication or ventilation equipment can affect machinery operation and ship safety.

Common Problems

Typical problems may include damaged switches, unclear identification, failed control circuits, inaccessible control stations or equipment that does not stop when commanded.

Crew unfamiliarity can also create a serious problem during an emergency. Familiarization and regular testing are therefore essential parts of machinery-space fire preparedness.

2026 Amendment Check

The January 2026 Supplement to the SOLAS Consolidated Edition 2024 incorporates amendments entering into force on 1 January 2026. The amendments include changes to several provisions of Chapter II-2, including fuel flashpoint requirements, fire-extinguishing media and fire safety for vehicle and ro-ro spaces.

The supplement does not introduce an amendment to Regulation II-2/5 affecting the emergency shutdown requirements discussed in this article. Accordingly, SOLAS II-2/5.2 remains the principal regulatory basis used here.

Key Takeaways

Main SOLAS reference: II-2/5.2

Ventilation shutdown: II-2/5.2.1.2 and II-2/5.2.2.2

Pump and equipment shutdown: II-2/5.2.2.3

Location of controls: II-2/5.2.2.4

Ventilation closures: II-2/5.2.1.1

Quick-closing valves: separate but related requirement under II-2/4.2.2.3.4

The basic principle is straightforward:

Stop → Isolate → Control fire growth

Conclusion

Emergency stops and shutdowns allow the crew to stop specified machinery and ventilation systems from safer locations during a fire.

Together with ventilation closures and quick-closing valves, these arrangements help reduce the supply of air, fuel and oil that could contribute to fire growth.

For seafarers, knowing where the shutdown controls are located, what each control operates and when they should be used is an essential part of machinery-space emergency preparedness.

References

International Maritime Organization (IMO). (2024). SOLAS Consolidated Edition 2024. London: IMO.

International Maritime Organization (IMO). (2026). SOLAS Consolidated Edition 2024 – Supplement, January 2026. London: IMO.

International Maritime Organization (IMO). SOLAS Chapter II-2 – Fire Protection, Fire Detection and Fire Extinction, particularly Regulation 5 – Fire Growth Potential.