Engine Room Fire: Lem Verbena

Engine Room Fire Alert: Cargo Vessel Lem Verbena – NTSB MIR-26-08

What Happened: On January 4, 2025, the bulk carrier Lem Verbena experienced a severe engine room fire while docked in Mobile, Alabama.

While the crew was offloading cargo, a fire alarm sounded for the upper engine room zone near the composite boiler. Ignited fuel dropped from the upper deck, rapidly spreading the fire downward.

The crew successfully secured the space, shut off fuel pumps and ventilation, mustered, and released the carbon dioxide fixed fire extinguishing system, which ultimately extinguished the fire. There were no injuries or pollution, but the vessel suffered an estimated $5.5 million in damage.

Investigators traced the root cause to the boiler’s burner unit. An O-ring seal on the oil fittings block failed because two fuel ports were radially misaligned. This uneven gap caused the O-ring to overlap into the fuel port and become pinched, compromising its seal. Additionally, a software settings error on the boiler unit’s SD card kept the fuel pump running continuously, even when the burner cycled off. This exposed the pinched O-ring to constant pressurized fuel, accelerating its degradation until it failed. The resulting spray of pressurized diesel fuel atomized and ignited on a nearby hot surface.

Immediate Operational Checks: Engineering Officers and crew must take immediate action to prevent this onboard.

1. First, verify the operational settings of your boiler’s burner units. Check that the fuel pump automatically shuts off when the burner cycles off in between cycles.
2. Second, inspect all accessible fuel line blocks and fittings near hot surfaces for minute leaks or weeping seals. Ensure protective lagging on engine exhausts beneath burner units is intact to protect against fuel leaks.

Lessons Learned:

• Verify Software Settings: Following any maintenance, test the system fully to ensure control software commands equipment correctly, such as shutting down pumps when not actively firing.
• Inspect Seals Carefully: When reassembling fuel blocks, ensure parts align perfectly. A pinched O-ring creates a fatal weak point in pressurized systems.
• Maintain Protective Lagging: Ensure all hot surfaces, especially exhaust pipes routed near fuel sources, are thoroughly insulated to prevent atomized fuel from igniting.
• Train for Rapid Response: The crew’s quick action to secure ventilation, shut off fuel, muster, and deploy carbon dioxide maximized the system’s effectiveness and saved the ship.
• Coordinate with Shore Firefighters: Good communication regarding soak times and sealed spaces allows carbon dioxide to displace oxygen safely and effectively.

Replace hoses and seals before they fail. Test emergency cut-offs and stops. Maintain good housekeeping, and remove combustible materials.

Tags: Engine Room Fire, Boiler Maintenance, Marine Safety, Incident Report

Official Report:

Read the official report here courtesy of the US, NTSB.