Transport Malta’s Marine Safety Investigation Unit has issued an investigation report on the MV CAPE KORTIA fire in the engine-room, which took place on January 20 2023 at the port of Rodman, Panama, leading to the loss of all power.
The Incident
At around 0850 (LT), a wiper noticed a leak of oil on the second platform inside the machinery spaces. Walking closer to investigate, he discovered a fire and smoke over diesel generator no. 4. By the time the situation was reported to the bridge and the main engine stopped, dense smoke had already dispersed inside the machinery spaces. Initial attempts by the crew members to apply boundary cooling helped minimise the spread of the fire but not extinguish it. The fire was extinguished after the release of CO2. It was determined that the most likely cause of the fire was a weld fracture on the fuel oil system’s mixing tank.
Investigation
The purpose of a marine safety investigation was to determine the circumstances and safety factors of the accident as a basis for making recommendations, and to prevent further marine casualties or incidents from occurring in the future.
Fire – Fuel and source of ignition
Several days after the fire, damages were observed on the vessel’s fuel oil system mixing tank, located high above platform no. 1. A failure of the weld seam on the mixing tank caused the leak. The leak, initially thought to be near DG no. 4, was confirmed by crew members to originate from the first platform above the generators’ platform. The vessel was maneuvering at the time, and the crew member’s observations matched with the fact that the main engine was burning MGO. The investigation hypothesized that the weld seam failure was the cause, but due to lack of access to the damaged mixing tank, the quality of the weld and the technical cause of the failure couldn’t be determined.
Observed damages to the fuel oil system mixing tank
The safety investigation lacked access to the damaged mixing tank, and no metallurgical tests were conducted to ascertain the weld failure’s technical cause. The mixing tank had been installed for several years without reported issues, and prior certifications attested to the correct steel use, testing, and weld penetration. Despite concerns about corrosion and pitting of the weld metal, no explosion had occurred inside the tank, as evidenced by the absence of dangerous build-up of flammable vapors and the damages being concentrated around DG no. 4’s alternator.
Conclusions
According to transport Malta’s investigation:
- In all probability, the immediate cause of the fire was a marine gas oil leak coming in contact with a hot surface on DG no. 4.
- The source of the marine gas oil leak was a weld failure on the vessel’s fuel oil system mixing tank.
- The possibility of weld material corrosion was not excluded.
- Without an evident cue of leakages, it would have been impossible for the crew members to detect the possible structural deterioration of the mixing tank.
- The initial attack on the fire was critical to the successful containment of the fire, albeit not successful to extinguish the fire.
- The crew members’ actions remained coherent and applied boundary cooling after closing all the quick closing valves.
- The timely activation of the fixed fire installation and the release of the CO2 was carried out in an organized manner.
Safety actions taken during the course of the safety investigation
As soon as it was determined that the fuel oil system mixing tank had a weld failure, a circular letter was issued to the vessel’s under the management of the Company. The mixing tanks installed on board four sister vessels were thoroughly inspected. The lagging was removed, and welding seams were checked for cracks. Repairs were carried out, where necessary.
