Engine-room flooding: isolate, pump, or evacuate?

First actions are to control the flooding and protect people, not to diagnose the pipe. The engineer should:

• Inform the bridge immediately and call the master; raise the engine-room alarm if crew assistance is needed.
• Start the bilge pump and any available portable/emergency pump.
• Reduce or stop the source if it can be done from outside the flooded area-close the sea-water suction or isolate the cooling system from a safe valve station.
• Keep personnel out of water that may be in contact with live electrical equipment; check whether the electrical panels are above the water line and isolate them if safe.
• Close watertight doors and monitor bilge levels in adjacent spaces.

Entry to isolate the pipe is justified only if the water is not contacting live electrical equipment, hot surfaces are isolated or guarded, a second person stands by, and the isolation can be done quickly with a clear escape route. With a net inflow of about 30 m³/h (80 m³/h in, 50 m³/h out), the water is rising but not explosively; a 10-minute isolation is worth attempting if the electrical risk is controlled. If water is already at live panels or the space is becoming unsafe, the engineer should withdraw and isolate from outside.

The master must treat flooding as a stability problem, not only a machinery problem. Considerations:

• Free surface effect: water in the engine room reduces metacentric height; the vessel may develop a list or become tender.
• Trim and draft: check forward and aft drafts and any change in list; water in a low engine room may initially improve stability but free surface can quickly reduce it.
• Pumping overboard: pumping sea water out is generally preferable to transferring it to another space, but the master must ensure the discharge does not create a new hazard and that pump capacity is not lost.
• Watertight integrity: close doors, hatches, and vents that could let water spread to the shaft tunnel or cargo holds.
• Grounding: on a bulk carrier with uncontrolled flooding, beaching in shallow water may be considered before the vessel becomes unmanageable, but only with navigational and environmental assessment.

Reasoning: A 30 m³/h net inflow can be managed if isolation succeeds, but if it continues, the cumulative free surface and loss of buoyancy may become more dangerous than the machinery damage. The master should set a trigger point-for example, water reaching a named frame or electrical panel-for evacuating the space and sealing it.

External notification should begin once the flooding is not clearly controlled. The master should:

• Send an urgency message (PAN PAN) or distress message (MAYDAY) depending on whether the vessel is in grave and imminent danger.
• Inform the company and, if near a coast, the coastal state or port authority.
• Brief the crew on muster stations and prepare the emergency generator, fire pumps, and life-saving appliances.

Abandoning the engine room-not necessarily the ship-is appropriate when water reaches live electrical equipment, the space cannot be isolated, or the flooding threatens the vessel's stability. The crew should seal the space, continue pumping from outside if possible, and keep the main engine running only if it can be done safely. The master should not delay notification until the decision to abandon the vessel is unavoidable; early notification gives SAR and salvage assets time to respond.