Discover the Cg-Storis: Ratings & Maritime News

The National Transportation Safety Board (NTSB) has concluded that the grounding and subsequent loss of Shell’s Arctic drilling rig, Kulluk, in December 2012 stemmed from a poor evaluation of towing risks during a winter storm across the Gulf of Alaska. The findings, released recently, pointed out that no single mechanical failure or error caused the incident. Instead, it was the lack of a robust safety margin in the towing plan that ultimately led to the accident. This flawed plan was designed to transport the conical drilling unit during a period known for severe weather, driven by factors not directly related to operational safety. On December 31, 2012, the Kulluk lost its tow lines in rough waters after leaving Dutch Harbor, near Kodiak Island, and grounding on the uninhabited Sitkalidak Island. The NTSB's report states: “The probable cause of the grounding of the mobile offshore drilling unit Kulluk was Shell’s inadequate assessment of the risk for its planned tow of the Kulluk, resulting in implementation of a tow plan insufficient to mitigate that risk.” After the grounding, the Kulluk sustained significant damage, leading to its eventual scrapping, while it has since been replaced by the Polar Pioneer, which is currently stationed at Terminal 5 in the Port of Seattle. Since that tumultuous attempt in 2012, Shell has refrained from returning to Arctic drilling, managing to complete only a portion of one well in the Chukchi Sea before inclement weather forced a retreat of its drilling vessels. The Polar Pioneer and the Noble Discoverer were expected to drill six wells during the brief summer and early fall months when the Chukchi Sea is usually ice-free. The U.S. Coast Guard blamed both Shell and its subcontractor for the decision to tow the Kulluk through the notoriously stormy Gulf of Alaska, suggesting that the move may have been an attempt to evade a looming state tax obligation set to take effect on January 1, 2013. Edison Chouest, the subcontractor responsible for towing, initiated the operation on December 21, 2012, but disaster struck on December 27 when the Kulluk’s tow line separated amid fierce storms, coinciding with failures of the Aiviq's engines. Efforts to reconnect a new tow line failed, further complicating the situation as the Coast Guard evacuated most of the Kulluk’s crew and provided spare parts to the Aiviq. Ultimately, the Kulluk ran aground just three hours and 12 minutes before the new year. In 2015, Shell's revised drilling plan received approval from the Bureau of Ocean Energy Management, a division of the U.S. Interior Department, but it still awaits final clearance from the Bureau of Safety and Environmental Enforcement.

A critical engine failure aboard the tugboat 'Aiviq' resulted in the grounding of Shell's conical drill vessel 'Kulluk' near Kodiak Island in late December 2012. The incident occurred while the 'Aiviq' was en route from Dutch Harbor to Seattle for winter maintenance. The U.S. Coast Guard's report, released on April 3, revealed that all four engines on the 'Aiviq' stopped functioning after seawater infiltrated the fuel system through deck vents. Design flaws on the vessel led to these vents being exposed to heavy seas, resulting in water accumulation on the aft deck during rough weather conditions. On December 27, the vessel faced particularly severe weather, causing the tank vents to become submerged, which allowed seawater to enter the fuel system. The investigation pointed to operational discrepancies on the part of Edison Chouest, the vessel's operator, who was found to have deviated from proper fuel management protocols. Even under the approved fuel system configuration, the methodology used may not have effectively prevented engine failure, as the vent system remained vulnerable to water intrusion. Moreover, the chief engineer's oversight of potential water contamination risks through the vents raised concerns about operational judgment. Inspection records documented issues of water contamination and fuel purification challenges leading up to the incident. Testing of the ultra-low sulfur diesel at Delta Western's bulk fuel tanks revealed no immediate signs of water contamination, albeit an unusual emulsion formed when mixed with seawater. Notably, extensive corrosion found on critical engine components contributed to injector failures. The report ultimately highlighted deficiencies in risk management practices by both Shell and Edison Chouest, particularly regarding their lack of experience in Arctic waters during winter conditions. It noted that poor judgment in undertaking the voyage in such challenging circumstances was a significant factor in the grounding. The U.S. Coast Guard emphasized the need for improved safety measures, recommending that stakeholders in the Arctic shipping industry establish guidelines, safety checklists, and enhanced operational procedures. Additionally, it proposed a working group to tackle towing issues pertinent to offshore drilling units in Arctic environments. Shell has committed to reviewing the findings from the Coast Guard's report in relation to their internal operational improvements and recommendations from the U.S. Department of the Interior, aiming to fortify safety protocols in the future.

On February 26, 2023, the offshore support vessel "Aiviq" played a crucial role in escorting the tugs "Corbin Foss", "Ocean Wave", and "Lauren Foss" as they towed the conical drilling unit "Kulluk" from Kiliuda Bay, located 48 miles southwest of Kodiak City, Alaska, toward Dutch Harbor for subsequent transportation to Asia. The operation also saw the involvement of the tugs "Warrior" and "Guardsman", alongside the vessel "Nanuq", enhancing the safety and efficiency of the tow. To ensure a secure operation, a safety perimeter was set up around the Kulluk, and an MH-60 Jayhawk helicopter crew from Air Station Kodiak conducted an overflight to assess the area for any potential security issues. For detailed visuals and further insights, visit the report with photos here: http://www.uscgnews.com/go/doc/4007/1712119/Multimedia-Release-Coast-Guard-conducts-overflight-of-Kulluk-tow-from-Kiliuda-Bay-Alaska.