Tug engine failure blamed on water in fuel
It is a mariner’s worst nightmare: At sea, in a bad storm, pulling a heavy load and working to keep control in a dicey situation.
Then, all the engines quit. And won’t restart.
Precisely this event occurred in late December 2012 to the crew of the Edison Chouest vessel Aiviq as it struggled to keep towlines on Shell’s conical drill vessel Kulluk.
The effort failed. The Kulluk went aground off Kodiak Island and was a total loss, which is now well known and documented. It was a miracle that there were no injuries or loss of life, and the evacuation of 18 crewmembers from the Kulluk’s heaving deck by Coast Guard helicopters during the storm was an exploit that should go down in maritime history.
The grounding itself occurred on a small island off Kodiak’s southern shore as Shell was transporting the Kulluk from Dutch Harbor to Seattle for winter maintenance.
But a big puzzle in the marine community since the grounding has been why all four of the engines on the Aiviq quit, particularly because the vessel was virtually brand new.
Luckily the U.S. Coast Guard cutter Alex Haley and Crowley Maritime’s tug Guardian were able to get to the scene to lend assistance, although they couldn’t save the Kulluk.
What immediately occurred to people in the marine industry was that some problem with the fuel supply to the engines occurred on the Aiviq. This has now been confirmed by the official U.S. Coast Guard report on the grounding, which was released April 3.
Seawater had gotten into the fuel system through vents on the deck that were exposed to waves buffeting the Aiviq. There were times in fact when the rear deck of the vessel, including the vents, was submerged.
The design of the newly-built Aiviq led to the vents being placed in a way that they would be exposed to water in rough seas, the Coast Guard report indicated.
In describing circumstances that led to the engine failures, the Coast Guard said: “Due to the Aiviq design, water regularly washes onto the aft working deck area during high seas…particularly while towing. This seawater tends to be carried back and forth across the deck as the Aiviq rolls.”
Very heavy weather encountered on Dec. 27, “created an environment where the tank vents…would be subject to water immersion, potentially being completely submerged at times. Any failure of the … vents would allow water into the common vent/overflow header,” from where it could enter the fuel system under certain circumstances.
The Coast Guard also criticized Edison Chouest for operating the fuel system in a way that was different than the prescribed procedure but also added that “had the Aiviq operated under the approved fuel system configuration, it is not clear whether it would have mitigated or prevented the loss of the main engines,” because the vent system still offered a means for water intrusion into the tanks.
The report was also critical of actions of the vessel’s chief engineer in gauging possible water intrusion. Also, “the Chief Engineer did not realize the potential for water intrusion through the vents,” the Coast Guard report said.
“The Aiviq engineering personnel did not use the redundant fuel management systems aboard the Aiviq to protect the critical fuel system from contamination. Protective fuel system configurations, intended to segregate all engines and generators in approved guidance was not following. In addition, no formal fuel management procedures were onboard the Aiviq for crew use and reference,” the report said.
The Coast Guard also said water contamination and other fuel purification issues were noted in engineering logs immediately prior to the casualty, or grounding.
Also, tests at the Delta Western bulk fuel tanks in Dutch Harbor on the same ultra-low sulfur diesel loaded onto the Aiviq before its departure revealed no water contamination. However, “the tests did exhibit an unusual and unexplained characteristic wherein an emulsion formed when the fuel was mixed with fresh water or seawater,” the report said.
The Coast Guard also found, “extensive corrosion on the main engine and generator injector internal parts. This corrosion contributed to a failure of the injectors of the main engines.”
Although the fuel problems and engine failures were cited, the Coast Guard report mainly singled out risk management practices by both Shell and Edison Chouest for criticism.
A senior Coast Guard official, Rear Admiral Thomas Ostebo, also cited the lack of experience of Edison Chouest in northern waters. Ostebo is the commandant of Alaska’s 17th Coast Guard District, and wrote a review of the report that is included with the document.
In its report, the Coast Guard said, “A series of events contributed to the causal factors that resulted in the grounding of the Kulluk, with the most significant factor being the inadequate assessment and management of risks associated with a complex vessel movement during the winter in the unique and challenging operating environment of Alaska.”
Ostebo went further in his criticisms: “The most significant factor was the decision to make the voyage (with the Kulluk) in the winter,” the rear admiral wrote in his review of the report. He faulted Shell and Edison Chouest for risk management and also their application of towing measures.
He said the master, chief engineer and third mate of the Aiviq, may have been negligent, and that the vessel Aiviq had experienced problems prior to the accident that were not reported to the Coast Guard, which are potential violations of law. The incidents are now under investigation.
“Mariners who have experience working offshore in the Gulf of Mexico do not necessarily possess the knowledge of the unique hazards that exist in the Gulf of Alaska,” he wrote.
Ostebo went on to recommend that Edson Chouest or other companies working in the Arctic develop specific guidelines, safety checklists and other procedures.
Rear Admiral Joseph Servidio, the Coast Guard’s assistant commandant for prevention policy, agreed with the report’s major conclusion that there was, “Inadequate assessment and management of the risks by the parties involved (Shell and Edison Chouest). Vessels and the operations are growing more complex and the risks that accompany these operations increase, whether in Alaskan waters or not. The failure to (adequately) understand and not completely assume past practice to address new risks is critical both in company practice and culture,” Servidio wrote.
“In this case the risks associated with a single vessel tow by a new purpose-built vessel of a unique conical-shaped hull, with people aboard, in winter Alaskan waters, where weather systems and sea are expected to rapidly develop, were extremely high.”
The report itself made several safety recommendations including that the U.S. Coast Guard Commandant and the Towing Safety Advisory Council establish a working group to draft a statement addressing issues raised by the accident, and other issues related to towing offshore drilling units in the Arctic.
The report also recommended a review of standards for ocean towing systems to include “inspections and non-destructive testing of towing equipment, detailed review of tow configurations to include history of towing equipment such as shackles, connector links and bridge chains.”
In a written response, Shell said: “We are reviewing the Coast Guard’s report on the Kulluk towing incident. We appreciate the thorough investigation and will take any findings seriously.”
“Already, we have implemented lessons learned from our internal review of our 2012 operations. Those improvements will be measured against the findings in the U.S.C.G. report as well as recommendations from the US Department of Interior.”
Edison Chouest was not available to comment on the report.
Alaska U.S. Sen. Lisa Murkowski said the Coast Guard report “has made a number of good recommendations to improve the safety of maritime activities as exploration of the Arctic moves forward. I believe that we can safely develop our energy resources in the Arctic, but it requires that we adhere to world-class safety standards.”