Engine-room fire with a missing crew member: CO2 release decision

Before release, the master must establish that the space is sealed and that no one is inside, or that entry is impossible. The critical fact is that CO2 displaces oxygen; releasing it into an occupied engine room would kill the missing oiler. Therefore the sequence is:

1. Complete the muster and confirm the missing person's identity and last known location.
2. Shut all ventilation, skylights, and doors; stop fuel and machinery; continue boundary cooling.
3. Attempt a search only if a properly equipped BA team can enter safely, with a charged hose line, thermal imaging, a backup team, and a viable escape route.

A rescue attempt is justified only when the fire is not fully developed, access is tenable, and the entry does not prevent resealing the space. Because the oiler was last seen near the auxiliary boiler, that area should be searched first if conditions allow. If heat, smoke, or fire growth makes entry untenable, the master should reseal the space and release CO2 rather than let the fire spread to the accommodation or machinery adjacent to the engine room. The decision must be recorded, and the missing person's last known position passed to the SAR authorities.

Post-release, the priority is to keep the space sealed and prevent reflash. The master should:

• Maintain boundary cooling and a fire watch on all boundaries.
• Keep the CO2 space and engine-room openings closed; do not open for a quick look.
• Monitor adjacent spaces for CO2 leakage and for temperature rise.
• Account for the missing person and notify the company and MRCC; prepare for a possible abandonment if the fire breaches boundaries.

Re-entry is not a time-based decision; it is an atmosphere-and-temperature decision. Entry should occur only after the space has cooled, the atmosphere has been tested (oxygen about 21%, CO2 within safe limits, no flammable or toxic gas), and a BA team with backup and portable extinguishers is ready. Ventilation should be established before unprotected entry, and the space should be checked for hidden hot spots and electrical isolation. Until then, the engine room remains a sealed casualty space.

The master is managing three competing risks: fire spread, a missing person, and the vessel's isolation. With the nearest vessel 18 hours away, there is no early external rescue; the crew must contain the fire themselves. The master should:

• Keep the bridge team focused on navigation and drift/sea keeping; a stopped vessel in sea state 5 still needs a proper lookout and position monitoring.
• Transmit an urgency or distress message as the situation dictates: a MAYDAY if the vessel is in grave and imminent danger, a PAN PAN if the fire is contained but assistance may be needed.
• Inform the company and MRCC of the missing person, the CO2 release, and the vessel's position.
• Prepare the abandon-ship decision in parallel: muster secondary stations, check lifeboat readiness, and brief the crew, but do not abandon merely because the fire is serious.

The reasoning is that abandoning into sea state 5 with an 18-hour rescue delay may be more dangerous than staying with a sealed, cooled engine room. The master should set clear trigger points for escalation-fire breaching boundaries, loss of watertight integrity, or uncontrollable smoke-rather than reacting to the alarm alone.