The U.S. Coast Guard cited safety failures by Transocean Ltd., the owner and operator of the Deepwater Horizon drilling rig, in the explosion last year that resulted in the worst offshore oil spill in U.S. history.
Poor maintenance of electrical equipment, the bypassing of gas alarms and automatic shutdown systems and a lack of training played a role in the April 20, 2010, catastrophe, which killed 11 people, injured 16 and left crude pouring into the Gulf for 87 days, the Coast Guard said in a 288-page report released Friday.
"We strongly disagree with, and documentary evidence in the Coast Guard's possession refutes, key findings in this report," Lou Colasuonno, a Transocean spokesman in New York, said in an e-mail.
"The Coast Guard inspected the Deepwater Horizon just seven months before the Macondo incident and certified the rig as being fully compliant with all applicable U.S. and international marine safety compliance standards, including those associated with fire and gas detection systems," Colasuonno said.
The Coast Guard said that the "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 Republic of the Marshall Islands, the rig's flag state, "effectively abdicated" its inspection responsibilities, according to the report.
The explosion and subsequent sinking of the rig, which was leased to BP Plc, has led to hundreds of lawsuits against BP and its partners and contractors.