Federal report hits Transocean over Gulf rig explosion

A new U.S. Coast Guard report concludes that “numerous” deficiencies on the part of Deepwater Horizon drilling rig owner Transocean Ltd. contributed to last year’s explosion in the Gulf of Mexico.

They include maintenance and training problems, and more broadly failure to instill a culture of safety. The report does not address the initial rupturing of BP’s well but rather the explosion on the rig and resulting fire and evacuation.

“Although the events leading to the sinking of Deepwater Horizon were set into motion by the failure to prevent a well blowout, the investigation revealed numerous systems deficiencies, and acts and omissions by Transocean and its Deepwater Horizon crew, that had an adverse impact on the ability to prevent or limit the magnitude of the disaster,” the report issued Friday states.

The preliminary report (available here) is part of a broader, ongoing joint investigation by the Coast Guard and the Interior Department into last year’s oil spill, which began with the April 20, 2010, blowout of BP’s Macondo well and the rig explosion that killed 11 workers.

The spill — the worst in U.S. history — dumped several million barrels of oil into the Gulf, an environmental disaster that prompted a months-long deepwater drilling freeze and major overhaul of federal drilling rules and oversight.

The report does not address the factors that initially led to the loss of “well control” at BP’s Macondo well and other drilling issues that are under the jurisdiction of Interior’s Bureau of Ocean Energy Management, Regulation and Enforcement, the agency conducting the probe with the Coast Guard.

Instead it explores numerous safety problems onboard the rig, and also faults oversight by the Deepwater Horizon’s flag state — the Marshall Islands — and says better Coast Guard oversight of foreign-flagged drilling units is needed.

Problems that investigators found include “poor maintenance of electrical equipment that may have ignited the explosion, bypassing of gas alarms and automatic shutdown systems that could prevent an explosion, and lack of training of personnel on when and how to shutdown engines and disconnect the MODU [mobile offshore drilling unit] from the well to avoid a gas explosion and mitigate the damage from an explosion and fire.”

“These deficiencies indicate that Transocean’s failure to have an effective safety management system and instill a culture that emphasizes and ensures safety contributed to this disaster,” the report states.

“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, chief of the Coast Guard's Office of Investigations and Casualty Analysis, in a statement Friday.

The report includes dozens of recommendations around maintenance, ventilation, improved fire protection and resistance on drilling rigs, as well as improved emergency drills and evacuation procedures and many others.

The final joint investigation report is expected to be released by late July.