The U.S. Coast Guard says "inadequate assessment and management of risk" was the primary reason for the grounding of the offshore drill rig Kulluk that went aground off of Kodiak Island in December 2012.

The Kulluk went aground on the eastern coast of Sitkalidak Island on Dec. 31, 2012.

The Coast Guard's report says "a series of events" contributed to the grounding, beyond lack of assessment during the winter and challenges of operating in Alaska,

Among the safety recommendations issued in the report is the recommendation that the U.S. Coast Guard Commandant partner with the Towing Safety Advisory Committee to establish a working group to draft and accept a task statement addressing, but not limited to, the issues raised by this marine casualty, the towage of mobile offshore drilling units in the arctic marine environment and several other concerns.

Rear Adm. Joseph A. Servidio identified in his assessment of the report a “multitude of specific factors that contributed to the casualty in the report.”

“The failure to adequately understand, respect and not complacently assume past practice will address new risks, is critical both in practice and in company 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 seas are expected to rapidly develop, were extremely high.”

The consequences of inadequate management of risks impacts all operators, Servidio reported, not just the specific company or party involved.

Servidio went on to note the troubling observation of the “significant number and nature of potential violations of law and regulations identified in the Enforcement section of the investigative report, including the failure to report marine casualties, failure to report safety-related vessel issues, and improper/illegal bridge and engineroom watch-keeping systems.”

The reports states the investigation determined a sufficient amount of evidence that a violation of law or regulation may have occurred on the part of Edison Chouest Offshore. The report blames the company for failing to report the “numerous marine casualties and safety related vessel issues contained in the report’s findings.”

The Kulluk’s grounding was preceded by a number of unexpected events with increasingly severe consequences, according to the report.

On Dec. 22, 2012, five days prior to the tug supply vessel Aiviq’s towline snapping while towing the Kulluk, the Aiviq Master sent a message to the Tow Master aboard the Kulluk, voicing concern, according to the report.

“To be blunt I believe that this length of tow, at this time of year, in this location, with our current routing guarantees an ass kicking,” the Master wrote. “In my opinion we should to the other side just as soon as possible.”

During the period while the tug supply vessel Aiviq was attempting to tow the Kulluk off the Coast of Sitkalidak Island the tug’s loss of main propulsion engines was likely due to fuel oil contamination by seawater, according to the report.

“Based on numerous log entries regarding replacement of main engine and ship service diesel generator injectors and clogged fuel oil flowmeters, it appears that the vessel had experienced fuel quality problems for months prior to the (loss of main propulsion engines),” according to the report.

The tug’s four main engines failed over a period of approximately four hours, likely due to extensive corrosion allowing seawater inside – an avoidable circumstance, according to the report.

“The crew did not routinely check fuel oil for the presence of water. It appears that the crew did not regularly drain the settling tanks, day tanks and primary filters for water,” the report states. “There were limited means on board to check for water in the fuel oil. There was a lack of formal fuel management practices on board the Aiviq.”

While Shell has not issued an official assessment of the Coast Guard’s report, company spokesperson Megan Baldino did say Shell is currently reviewing the report.

“We appreciate the thorough investigation and will take any findings seriously,” Baldino wrote. “Already we have implemented lessons learned from our internal review of our 2012 operations.”

Baldino noted those improvements would be measured against the findings in the USCG report as well as recommendations from the US Department of Interior.

The Coast Guard reminds companies that safety and risk management need to be a priority when evaluating maritime evolutions to ensure responsible, safe and efficient operations. Professional mariners have a responsibility to ensure they manage and follow approved procedures for all maritime operations to prevent and mitigate potential incidents.

The full 152-page report can be downloaded from the Coast Guard's website.

This is a developing story. Watch Channel 2 broadcasts and check for more. Channel 2's Matt Smith and Samantha Angaiak contributed to this report.