An engine room fire aboard the Malta-flagged liquid bulk carrier Endo Breeze that resulted in $1.2 million damages was the result of a maintenance error, according to the National Transportation Safety Board (NTSB).
The incident occurred on April 29, 2022, when the 2003-built ship was transiting outbound through the Raritan Bay West Reach channel near Staten Island, NY. As a result of the fire, the vessel lost propulsion.
The second engineer was conducting a round of the engine room when he smelled oil.
He later told investigators that when he opened the No. 1 cylinder fuel injector pump cover to investigate, fuel oil sprayed into the air from the 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.
The vessel was powered by two 8-cylinder MaK M-32 C, medium-speed diesel engines and to determine the cause of the oil spray, investigators examined the starboard engine’s No. 1 cylinder fuel injector pump and discovered a slight offset on its banjo tube assembly.
NTSB investigators determined that, in the case of the fire aboard 600-foot, 46,800 dwt ship, “it is likely that the engineer did not correctly follow the manufacturer’s procedure for fuel injector pump reassembly when performing maintenance a day before the fire.”
Investigators examined the engine’s No. 1 cylinder fuel injector pump to determine the cause of the banjo tube leak.
They found a slight offset – a “misalignment” – on the affected banjo tube assembly and that 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 had 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.”
The NTSB sent the banjo tube assembly to a third-party metallurgical testing firm for analysis with tests failing to find any material or dimensional issues with the banjo tube bolts or other involved parts.
The analysis, however, did find that “the tube had bent to accommodate the offset with fractures at both ends of the tube itself where it connects to the sealing flange and lid.”
The resulting stresses, the NTSB, found, “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.
“That is likely because the banjo bolts’ sealing surfaces provided a sufficient seal during the short, no-load testing,” it said.
“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.”
Due to the elevated 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,” it added.
The report also emphasized the need for training to prevent and contain engine room fires.
“The crew of Endo Breeze effectively contained the spread of a main engine room fire by removing fuel and oxygen sources and communicating effectively,” the NTSB said.
“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.”
That training “should also cover procedures for effectively shutting down machinery, fuel oil, lube oil, and ventilation systems, as well as boundary monitoring.”
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,” it added.
“The engine room fire in this casualty illustrates what can happen when equipment manufacturers’ recommended maintenance procedures are not followed,” the NTSB stated.
“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.” •