The National Transportation Safety Board (NTSB) has released an investigation report, about a fire started in the engine room of the 600-foot-long chemical tank ship Endo Breeze while the vessel was transiting outbound from Linden, New Jersey, through the Raritan Bay West Reach channel, to Bay Ridge Anchorage.
The incident
On April 29, 2022, about 1913 local time, a fire started in the engine room of the 600-foot-long chemical tank ship. The crew extinguished the fire using the engine room’s fixed carbon dioxide fire extinguishing system. As a result of the fire, the vessel lost propulsion and was anchored in the channel. No pollution or injuries were reported. Damage to the vessel was estimated at $1.2 million.
While the chemical tank ship Endo Breeze was maneuvering outbound through the Raritan Bay West Reach channel, a fire broke out in the engine room. The second engineer was conducting a round of the engine room when he smelled oil. He told investigators that when he opened the no. 1 cylinder fuel injector pump cover to investigate, fuel oil sprayed into the air from the no. 1 fuel injection pump banjo tube, which was near the operating engine’s exhaust manifold. As the engineers were calling the master to shut down the engine, the fourth engineer saw a fire on the starboard engine. Investigators found the fire pattern and surrounding heat damage near the outboard side of the starboard main propulsion engine at the no. 1 cylinder fuel injector pump to be consistent with the second and fourth engineers’ accounts of the event. Based on the fire damage and the engineers’ observations, oil spray from the banjo tube leak made contact with nearby hot surfaces on the starboard engine’s exhaust manifold and ignited.
To determine the cause of the banjo tube leak, investigators examined the engine’s no. 1 cylinder fuel injector pump and discovered a slight offset (misalignment) on the affected banjo tube assembly. The second engineer had replaced the no. 1 fuel injection pump earlier that day. He told investigators that he followed the manufacturer’s manual reassembly procedure, which required components to be tightened in a specific order to maintain alignment. However, if he tightened the banjo tube bolts before properly tightening the sealing flange and/or lid assembly to their specified torques, the pump sealing flange and/or lid assembly may not have been evenly aligned when the banjo tube was installed. Because investigators found an offset on the banjo tube assembly, it is likely that the engineer did not correctly follow the manufacturer’s reassembly procedure for the fuel injector pump.
The banjo tube was sent for third-party metallurgical testing. Metallurgical testing did not find any material or dimensional issues with the banjo tube bolts or other involved parts. However, testing found that the tube had bent to accommodate the offset, and fractures on both ends of the tube itself—where it connected to the sealing flange and lid—were discovered. Therefore, stresses associated with the offset likely caused the banjo tube to bend and fracture, causing the oil leak. After replacing the fuel oil pumps, the second engineer ran the main diesel engine (under no load) to inspect for leaks and found no signs of leaks or other issues from the fuel oil pumps or associated piping. This is likely because the banjo bolts’ sealing surfaces provided a sufficient seal during the short, no-load testing. But when the main engine was fully loaded with a full-ahead order, the expanding stresses (due to heat) caused the banjo tube to fracture. Therefore, although the second engineer properly tested the repair, the misalignment that led to the banjo tube failure only manifested once the engine was given a high load.
Probable Cause
The National Transportation Safety Board determines that the probable cause of the engine room fire aboard the chemical tank ship Endo Breeze was a main engine fuel injector pump replacement that was not conducted in accordance with manufacturer procedures, which resulted in a high-pressure fuel spray that ignited off the engine exhaust components.
Lessons learned
Diesel Engine Maintenance
The NTSB has investigated several recent casualties involving mechanical or fuel line fitting failures that led to engine room fires following maintenance of shipboard diesel engines. The engine room fire in this casualty illustrates what can happen when equipment manufacturers’ recommended maintenance procedures are not followed. In this case, not following the tightening sequence described in the diesel engine manufacturer’s manual led to the misalignment and failure of a high-pressure fuel connection on an engine’s fuel injector pump’s assembly. Due to the high risk of fire associated with pressurized fuel, when working with diesel engine components, it’s critical to carefully follow manufacturer assembly procedures and review manufacturer manuals and guidance on a regular basis to ensure familiarity with correct maintenance procedures.
Containing Engine Room Fires
The crew of the Endo Breeze effectively contained the spread of a main engine room fire by removing fuel and oxygen sources and communicating effectively. To prevent engine room fires and ensure they are effectively contained, operators should provide mariners realistic scenario-based training, including training that covers engine room emergencies. This training should also cover procedures for effectively shutting down machinery, fuel oil, lube oil, and ventilation systems, as well as boundary monitoring.
