The Alarm Is Not the Emergency — What Comes Next Is

The Alarm Sounded. The Officer Made What Seemed Like a Reasonable Decision. It Was the Wrong One.

An engine high temperature alarm sounds. The officer shifts the engine to neutral and keeps it running, believing the circulating water will bring the temperature down. The raw water pump had failed. With the engine still running but the cooling water no longer circulating, the engine and exhaust line continue to overheat. A water leak onto a hot surface generates steam. The crew focuses on the steam. Behind them, in the aft lazarette, an overheated exhaust line — suspended by wooden supports — ignites. The fire breaches the engine room bulkhead.

This is not a hypothetical. It happened. The US Coast Guard published it as a safety alert. And the lesson it contains is relevant to every vessel, every engine room, every engineer.

Understanding Why It Went Wrong

The fundamental error was an assumption: that the cooling system was functioning. The engine was running, the water was supposedly circulating — so the temperature would come down. But no one verified the actual state of the raw water pump before deciding to keep the engine running.

Once the pump failed, every subsequent decision was based on incorrect information. The steam from the water leak on the hot surface created a visible, attention-grabbing event — while the real fire was developing unseen in the lazarette. This is task fixation: the crew’s attention was captured by a visible symptom while the actual emergency grew unchecked.

Exhaust lines frequently penetrate bulkheads into spaces forward or aft of the engine room. When an engine overheats, these lines carry that heat into adjacent spaces. Wooden supports, insulation materials, and other combustibles in those spaces can ignite. Any sign of engine trouble should trigger inspection of all spaces where engine-related piping runs — not just the engine room itself.

The Correct Response Sequence

1. Sound the alarm and notify the bridge immediately. A high temperature alarm is a vessel-level emergency, not just an engine room problem. The Master needs to know so navigation decisions can be made in parallel.
2. Reduce load or shut down the engine. If you cannot identify the cause of overheating immediately, the safest default is shutdown. Continuing to run an engine without verified cooling gambles with catastrophic damage and fire risk.
3. Inspect the raw water system first — strainer, hoses, pump, impeller. Raw water supply failure is the most common cause of engine overheating. Check the strainer for blockage. Verify the pump is running. Check for hose damage or air ingestion.
4. Inspect ALL spaces where exhaust and fuel lines run. Do not restrict your inspection to the engine room. Feel bulkheads for unusual heat. Check for smoke, smell, or discolouration in adjacent spaces including the lazarette.
5. Do not restart until the cause is identified and rectified. Restarting a hot engine with an unresolved cooling problem — even briefly, even at reduced power — risks catastrophic damage and reigniting any fire that has started in the exhaust system.
6. Conduct a post-incident inspection of the entire cooling system before returning to full service.

Preventive Maintenance That Could Have Stopped This

• Impeller inspection and replacement on manufacturer’s schedule — do not wait for failure
• Raw water strainer cleaning at regular intervals based on operating environment
• Heat exchanger maintenance — check for fouling and leakage in jacket water and lube oil exchangers
• Exhaust system inspection — check insulation integrity, ensure lagging is in place and undamaged, verify no combustible supports are in contact with exhaust lines
• Regular engineering casualty drills — not just fire drills after the fire has started, but response drills for the early-stage casualties that cause those fires

Related Reading

• Kommandor Susan MAIB 2026 — how a generator fire from a 2019 maintenance failure played out
• Vessel Fire Safety — what the insurance data says about engine room fire causes
• Fire Hazard Prevention CIC 2026 — PSC will check your crew’s first-90-second response
• Enclosed Space Entry — lazarettes and voids adjacent to exhaust lines are enclosed spaces
• CHIRP Annual Digest — engineering casualty near-misses and common failure patterns