DNV Report Points To BOP Design Flaw gCaptain Total Views: 373 March 24, 2011 BP PLC came within 1.4 inches or less of preventing the worst offshore oil spill in U.S. history, say engineers studying the safety device that failed in last year’s Gulf of Mexico disaster. The device, known as a blowout preventer, was a massive set of valves that sat on the sea floor nearly a mile beneath the Deepwater Horizon drilling rig, which floated on the surface. It was equipped with powerful shears designed to cut through pipe and seal off the well in an emergency. Why the device failed has been one of the central mysteries of last year’s disaster. In a report released Wednesday, engineers hired by U.S. investigators say they have solved it: The force of the blowout bent the drill pipe, knocking it off-center and jamming the shears. Rather than seal the well, the blades got stuck 1.4 inches or less apart, leaving plenty of space for 4.9 million barrels of oil to leak out. The investigators concluded the blowout preventer failed as a result of a design flaw, not because of misuse by BP or any of the other companies involved, and not because of poor maintenance. The fail-safe device, the last line of defense against a disaster, wasn’t designed to handle a real-world blowout, according to investigators, who called for further study of the devices. “They have to rethink the whole design,” said Elmer P. Danenberger III, who is not involved in the investigation, but oversaw U.S. offshore drilling rules until he retired in December 2009. The investigators’ finding could be a problem for the oil industry. Drilling rigs around the world rely on blowout preventers, most of them with the same basic design as the one that failed on the Deepwater Horizon. The report doesn’t address what caused the blowout itself. That has been the subject of several other major inquiries, which all have found that a series of decisions by BP and its contractors set the disaster in motion. Even if the device h