Engineers move chamber toward Gulf seabed oil leak

BP Plc engineers using undersea robots maneuvered a massive metal chamber above a gushing ruptured oil well in the Gulf of Mexico on Friday, trying to contain a leak that threatens an environmental catastrophe on U.S. shores.

A BP video frame grab shows a remote operating vehicle (ROV) successfully capping one of the three leaks, May 5, 2010. REUTERS/BP/Handout

The four-story structure, BP's only short-term hope of controlling the leak, is aimed at capturing most of the unchecked flow of crude nearly 1 mile below the water. If connected successfully, it is hoped the device could pump oil from the bigger of two leaks to a surface tanker, capturing about 85 percent of the gushing crude.

But the technique has never been tried at that depth, where engineers guiding remotely operated vehicles battle darkness, currents and intense undersea pressure. Workers were prepping the seabed before landing the dome, which hovered over the leak in the oil-choked waters.

"It's a very delicate operation," BP spokesman Mark Salt said in Houston. "They're dealing with very dark waters, very, very deep."

Light oil washed ashore for the first time on a chain of islands off the Louisiana coast on Thursday as the slick expanded. At least 5,000 barrels (210,000 gallons/795,000 liters) have poured into the Gulf each day since the Deepwater Horizon rig exploded two weeks ago, killing 11 workers

BP says the containment dome could be operating by Monday. The company is drilling a relief well to halt the leak that could take two or three months to complete.

Engineers have also considered pumping heavy fluids into the top of the failed blowout preventer to plug the leaking well in a technique called "top kill." But that would be "a couple of weeks away," officials said, as BP tries to fix the blowout preventer with underwater robots.

BP has been under heavy pressure from Washington to meet its responsibilities in what could be the largest oil spill in U.S. history. After meeting with BP executives in Houston, U.S. Interior Secretary Ken Salazar said the company and its partners made "some very major mistakes.

"Its life is very much on the line here," Salazar told reporters. "Are they doing everything that they can possibly do? I hope that they are. I want to make sure that is in fact happening."

Salazar reiterated the U.S. government will issue no new offshore drilling permits until an inter-agency panel gives a safety review to President Barack Obama by May 28. In the meantime, existing drilling will continue