The Deepwater Horizon disaster that cost 11 lives and caused major pollution to the US Gulf Coast a year ago was the result of a tragic series of failures, an official report concluded today.

There were systematic failures in the safety management system of Transocean, the owner of the offshore drilling rig, but also fault elsewhere, a report from the US Coast Guard charged

“Deepwater Horizon and its owner, Transocean, have had serious safety management system failures and a poor safety culture manifested in continued maintenance deficiencies, training and knowledge gaps, and emergency preparedness weaknesses,” declares the report.

Oversight and regulation of the rig by the Marshall Islands flag state was also ineffective, with all inspection activities delegated to the DNV and ABS classification societies. The Marshall Islands “effectively abdicated its vessel inspection responsibilities,” the report contends.

And by not visiting or inspecting the Deepwater Horizon the Marshall Islands flag state lacked the ability to validate or audit the inspection reports produced by those it delegated its responsibilities to.

“Many well-known gaps in the “maritime safety net” for foreign-flagged mobile offshore drilling units (MODU) aligned and tragically failed to prevent the deaths of eleven people and the largest oil spill in US history,” the report says.

The report recommends that US Coast Guard oversight of foreign flagged MODUs be strengthened to improve safety.

"The safety management system failed to provide proper risk assessment, adequate maintenance and material condition, and process safety adherence. The flag state and the US Coast Guard did not identify these system failures in time to ensure the safety of the vessel,” the report notes.

The International Maritime Organisation’s regulations for MODU’s come in for criticism for not establishing clear requirements relating to electrical equipment.

The IMO’s MODU code is also regarded as insufficient in terms of providing for an adequate level of protection for major fires. The report says fixed deluge systems rather than manual fire hoses are required to fight major hydrocarbon fires.

The report calls on the commandant of the US Coast Guard to work with IMO to achieve multiple improvements in the MODU regulations.

The Deepwater Horizon rig operating in the Macondo field 40 miles off Louisiana suffered a blow out with the failure of the blow out preventer allowing a massive fire to burn out of control until the rig sank.

The US Coast Guard report reaches 61 conclusions, makes 54 safety recommendations and nine administrative recommendations.

Today’s report is not a final determination but a series of recommendations to the commandant of the US Coast Guard.

“This investigation seeks to prevent an accident similar to the Deepwater Horizon by identifying the factors that led to the tragedy and making recommendations to remove or minimize those factors in the future,” said Capt David Fish, the US Coast Guards head of casualty investigations.

“While nothing can bring back the 11 people who perished in this disaster, there is much that should be learned for the future,” Fish added.

The report also hails the fact that despite the deaths and injuries to 16 a total of 115 people successful survived the disaster.

Publication of volume two of the investigation has been postponed because of the ongoing investigation into the failure of the Deepwater Horizon’s blow out preventer.

The final joint investigation team report on the Deepwater Horizon loss is likely to be published in late July.

Click on the document in the in the related media column to the right to read the US Coast Guard report in full. Please note it is a large 20MB file.