The sheer magnitude of BP's oil spill in the Gulf of Mexico has led to the creation of the world's first oil containment dome. More of a giant box than a dome, the 93-ton, four-story-tall structure is the key component of one of three "subsea oil recovery systems" intended to be lowered onto three seafloor leaks spilling an estimated 210,000 gallons (795,000 liters) of oil a day into the Gulf of Mexico.

The first dome built by Welders in Port Fourchon, Louisiana on Monday arrived today at the site of the oil slick.

A report from National Geographic gives us this information and a set of images of the "dome" under construction:

BP engineers are working with the Wild Well Control corporation to convert structures originally used to cap shallow-water wells damaged during Hurricane Katrina in 2005. The Deepwater Horizon well is 5,000 feet (1,500 meters) below the surface—deeper than any oil-containment chamber has ever gone.

This is how it works
:

• The system is made up of a 125-ton, 14’ x 24’ x 40’ structure that will be set on top of the largest leak source. This leak is located at the end of the riser, about 600 feet from the wellhead.

• Equipment at the top of the system is connected to a 5,000 foot riser that will convey the hydrocarbons to the surface ship, the Deepwater Enterprise.

• Once in place, oil will flow up into the containment system’s dome to the surface ship.

• Once on the surface ship, the hydrocarbons will be processed and oil will be separated from water and gas. The oil will then be temporarily stored before being offloaded and shipped to a designated oil terminal onshore.

• The Deepwater Enterprise is capable of processing 15,000 barrels of oil per day and storing 139,000 barrels.

• A support barge will also be deployed with a capacity to store 137,000 barrels of oil.

• This system could collect as much as 85% of oil rising from the seafloor.

You can also watch videos from the BBC, here and here (in Spanish)