Venice, Louisiana: Workers lowered a huge dome over an oil leak gushing from a sunken rig deep in the Gulf of Mexico Friday as energy giant BP raced to contain a slick moving perilously closer to the US coast.
The unprecedented operation to drop the 100-ton (90-tonne) chamber some 5,000 feet (1,500 meters) below the surface to cap the leak was expected to be completed within hours Friday.
"They are in the process of lowering it now," BP spokesman John Curry told AFP about the operation seen as the best hope to stave off the biggest US environmental disaster since the 1989 Exxon Valdez spill in Alaska.
He described a "complex operation" involving maintaining the dome in a correct position with the ship, balancing the weight, placing the structure on the seabed and transferring control of the containment system from one ship to another.
Officials said the concrete and steel structure was moving at a rate of about 500 feet (150 meters) per hour.
Once it reaches the seabed, the 40-foot (12-meter) tall white box will have to be carefully fitted into place by remote-controlled submarines to cap oil gushing from the Deepwater Horizon oil rig that exploded on April 20, killing 11 workers.
BP officials, who leased the rig from Transocean, say they hope to have the dome operational by Monday, when a large part of the oil would then be funneled up to a containment vessel on the surface for storage and processing.
The British energy giant is racing to contain an estimated 200,000 gallons of crude spewing into the sea every day, threatening the ecologically fragile Gulf Coast wetlands and shoreline.
Political fallout over the spill grew as a key US senator warned that action on legislation to fight climate change was now "impossible" due to fierce new opposition to offshore drilling in the wake of the disaster.
"I believe it would be wise to pause the process and reassess where we stand," Republican Senator Lindsey Graham said.
There were also doubts the dome would be the silver bullet.
"It`s pitch black down there. There are no divers. And there are all kinds of currents," said Greg McCormack, director of the Petroleum Extension Service at the University of Texas.
Homeland Security Secretary Janet Napolitano, back from a tour of the region, said that dome or not, US officials were continuing to plan for the worst.
"Our planning in terms of preparation for more oil coming up to the surface of the gulf and heading toward those fisheries, beaches, et cetera, on the shore, the planning and preparations continue as if there were no dome being lowered," she told MSNBC television.
"We`re not going to be satisfied until the spill is stopped, the leak is cured, the mess is cleaned up and the claims are paid."
The oil response team has recovered some 30,000 barrels of oil-water mix so far, BP said Friday, with the US administration saying the British company is responsible for the clean-up and its costs.
Operations to skim oil from the surface of the water resumed as seas became calmer, and some 700,000 feet of boom have been deployed to prevent oil from reaching the shores.
Improved weather conditions also allowed workers to perform a controlled burning of surface oil.
Residents from Texas to Florida anxiously awaited the outcome of the risky operation, as failure would mean the crude would gush for three months until workers are expected to finish drilling a relief well.
Fears are growing that the disaster is already impacting sea life in a region home to vital spawning grounds for fish, shrimp and crabs and a major migratory stop for rare birds.
Louisiana has ordered an "emergency" halt to shrimp harvesting in waters near the mouth of the Mississippi River, and the state extended a ban on commercial and recreational fishing.
Overflights showed the sheen that marks the advancing edge of the massive slick hovering off the Louisiana coast, as well as heavier oil on both sides of the Chandeleur Islands, about 100 kilometers (60 miles) east of New Orleans.
Some 10,000 officials and volunteers have fanned out across shorelines and in more than 260 vessels to help contain the spill and protect the coast, according to BP and the US Coast Guard.
Although oil has not yet reached land in large quantities, experts have warned an environmental disaster was already developing in the deep waters of the Gulf of Mexico.
Bureau Report
