BP fit new Gulf of Mexico oil cap

BP robots have attached a new, tighter-fitting cap on top of the gushing Gulf of Mexico oil leak, raising hopes that the crude could be kept from polluting the water for the first time in nearly three months.

Placing the cap on top of the leak was the climax of two days of delicate preparation work and a day of slowly lowering it into position a mile below the sea. It is a temporary fix, but the oil giant's best hope for containing the spill.

In the next few days the oil company will test the 18-foot-high, 150,000-pound metal stack of pipes by gradually shutting off valves.

There are risks involved in the new operation: "You could over-pressurise the pipe and cause it to explode causing mini-leaks along the pipe," said Dr. Michio Kaku, a physicist and author of the book, "Physics of the Impossible."

Residents have been sceptical BP can deliver on its promise to control the spill, but the news was still welcome on the coast.

"I'll be happy to see them at least cap it so we know what we got in the water. Right now, it's blowing out so much oil, and nobody knows what it is," said Mack Breaux, a commercial fisherman whose business has been decimated since the spill.

A permanent fix will have to wait until one of two relief wells being drilled reaches the broken well, which will then be plugged up with drilling mud and cement. That may not happen until mid-August.

So far between 89 million gallons and 176 million gallons of oil have poured into the Gulf, according to government estimates. The spill started on April 20 when the Deepwater Horizon rig exploded and burned, killing 11 workers.