An engine room fire aboard the container ship MOL Prestige injured several crew. Why did it happen, and can lessons be learned from such a serious maritime incident?
In January 2018, a fire broke out in the engine room of the container vessel MOL Prestige, 150nm west of British Columbia, Canada. By the time it was extinguished five crew had suffered serious injuries from burns and smoke inhalation.
An investigation by the Transportation Safety Board of Canada (TSB) identified a number of onboard safety deficiencies.
When alarms first sounded aboard MOL Prestige, the engine room crew rushed to the engine control room (ECR) to troubleshoot the situation.
Faced with an unidentified class of fire, they focused on following fire-response procedures from the ECR rather than mustering to a safe location outside the engine room. When they eventually tried to exit the engine room minutes later, thick black smoke had built up in the engine room and the heat had risen sharply. They were not wearing EEBDs ( and aborted their attempts to escape, retreating back to the ECR to await rescue. This delayed activation of the CO2 fire suppression system and allowed the fire to continue burning unabated.
Trapped in the engine control room
Meanwhile, thinking the engine room was only filled with smoke, the chief officer ordered an able seaman to take EEBDs to the engine crew. The able seaman entered the engine room alone – normally crew are partnered for safety – but he had to turn back after encountering thick, toxic smoke. The chief officer then took the SCBA (self-contained breathing apparatus) from the able seaman and entered the engine room himself but without having put on a firefighting outfit, still under the impression there was no actual fire.
On reaching the ECR, the chief officer had to demonstrate to the trapped crew how to put on their EEBDs, causing further delays.
Once the group had left the engine room the master released the CO2. However, some CO2 cylinders failed to release their contents and the fire continued, with the system giving no indication or alert to the master that it had partially failed.
The MOL Prestige in port (Credit: Shutterstock)
Investigation: Factors leading to the fire
The Transportation Safety Board of Canada investigation found that just before the fire started, MOL Prestige had been sailing through an emission-control area during which time it burned low-sulphur marine gas oil (LSMGO) and experienced intermittent leaks of LSMGO from the main engine fuel-injection system. The LSMGO from these leaks drained into the drain tank, as per design. As a result, the settling tank contained 30m3 of a mixture of heavy fuel oil (HFO) and LSMGO.
Overheated settling tank
The steam valves leaked into the steam heating coils, heating the settling tank above its normal temperature. The high temperature alarm didn’t sound as it had been set to activate only when the tank temperature exceeded 120°C. Engine room crew members were only alerted to the high temperature in the settling tank when the high-temperature alarm for a purifier oil inlet sounded.
To reduce the temperature of the settling tank, cooler HFO was transferred from a bunker tank into it. However, the initial suction from the bunker tank was most likely water that had settled at the bottom. While the ship was using LSMGO in the emission-control area, the water settled at the bottom of the tank at the level of the transfer pump suction pipe. When the cooler, oily water mixture came into contact with the much hotter oil in the settling tank, the water turned to steam, expanding in volume.
The point of least resistance
With space in the settling tank limited, the expansion caused the hot oil to be forced out through all available openings (frothover), which included the overflow pipe, the air vent, the outlet to the purifier, the transfer pump filling pipe, and the open pipe on the settling tank. Oil was also pushed back into the overflow pipe for the service tank and the tank outlet line to the purifier, which caused the steam and fumes issuing from the purifier hopper to increase. The contents of the tank were forced through the open pipe on the settling tank, which was the point of least resistance.
Fire pattern analysis
Fire pattern analysis of the events indicated that the oil flowed out of the pipe and down the side of the settling tank, coming into contact with an ignition source and catching fire. The burning oil then fell to the decks below, while the flames travelled back to the top of the settling tank.
MOL Prestige has been in trouble before
The 2018 fire isn’t the first time MOL Prestige has run into trouble. In 2007, under a different name, MSC Prestige, it collided with a tanker near the Red Sea traffic separation scheme, with both vessels suffering severe bow damage. Images from the time show just how serious that damage was.
Other notable incidents involving MOL ships include the case of MOL Comfort, which broke in two before sinking 200nm off Yemen in June 2013, casting doubts at the time about rules governing structural integrity; and the bulk carrier Wakashio (owned by Nagashiki Shipping Co. and chartered to MOL) which ran aground off Mauritius and was stranded on a coral reef this summer, spilling at least 1,000 tons of oil and causing severe environmental damage before, once again, breaking in two.
Read the full official MOL Prestige engine room fire investigation report here.
Dennis O’Neill is a freelance journalist specialising in maritime.