**A steel dome designed to cap the damaged oil well polluting the Gulf of Mexico could be operational by later on Thursday, BP says.**The latest bid to plug the gushing well comes after previous efforts to stem the flow failed.
An attempt to use a larger containment dome failed on Sunday when it became clogged with ice and gas.
Some 15m litres of crude oil has so far leaked into the Gulf from the sunken Deepwater Horizon rig.
Engineers now hope a smaller dome, known as a top hat, might stem at least some of the oil.
That dome is now on the sea-bed and engineers hope to link a second pipe to the end of the pipe supposed to pump oil from the sea floor, BP says.
BP hopes this pipe will funnel away oil that had collected in the original piping - or riser - into container ships on the surface.
But there is no guarantee that the plan will work, says the BBC’s US correspondent Andy Gallacher.
And if it fails, BP may have to drill a relief well which, our correspondent adds, could take weeks.
Human hair
Emergency teams are using several methods in their attempts to deal with the oil at the surface.
Thousands of clean up crews, soldiers and volunteers have all been deployed to keep the expanding oil slick from damaging the coastlines of four states.
Around 1.5m ft of floating booms are being used as part of the efforts to stop oil reaching the coast, Reuters reports.
A US charity is even making booms out of nylon tights, animal fur and human hair.
Hair donations have been sent from around the world to help make the special booms, which will be laid on beaches to soak up any oil that washes ashore.
Eleven people died when an explosion - thought to have occurred after a surge of methane gas from deep within the well - destroyed the Deepwater Horizon rig on 20 April.
Huge bill
The huge oil spill has so far cost BP - which is in charge of the clean-up operation - $450m (£300m).
The total bill could be as high as $20bn (£13.6bn), analysts say.
"Estimates run from between $3bn to $20bn. Certainly, there’s the clean-up costs.
“And the associated lawsuits, which at this stage looks like it could be one of the largest class actions in US history”, oil analyst Greg Smith of stock market research house Fat Prophets told the BBC.
“From our point of view, we would think somewhere mid-range - around the $10bn mark,” he adds.
Underwater efforts to cap oil leak
Initially, BP tried to lower a 125-tonne, 18-metre (40 feet) high container dome over the main leak on the sea floor. However, this failed when gas leaking from the pipe mixed with water to form hydrates, ice-like crystals, that blocked up the steel canopy.
Instead, engineers have lowered a smaller device onto the site. Dubbed the Top hat, it will sit over the tear in the pipe and partially stop the leak. To prevent the build up of hydrates, methanol is pumped into the top hat to disperse the water and gas.
The top hat is 1.5m (5 feet) high and 1.2m in diameter. Two special side lines are used to pump methanol into the top hat to displace water and gas leaking from the broken oil pipe. This should prevent the build-up of hydrates. Once in place, oil can be pumped up to the surface.
BP plan to lower the original subsea containment dome over the top hat to provide a better seal over the leaking site and pump oil up to the surface. This time, it will be attached to a pipe that can pump warm water into the dome to prevent the build-up of hydrates.
This article is from the BBC News website. © British Broadcasting Corporation, The BBC is not responsible for the content of external internet sites.
http://feeds.feedburner.com/~ff/bbcnewsworldfullfeed?d=yIl2AUoC8zA http://feeds.feedburner.com/~ff/bbcnewsworldfullfeed?d=dnMXMwOfBR0 http://feeds.feedburner.com/~ff/bbcnewsworldfullfeed?i=Aeg1heeFFV0:NbIGx_duLLw:V_sGLiPBpWU
http://feeds.feedburner.com/~r/bbcnewsworldfullfeed/~4/Aeg1heeFFV0