Blowout preventer failed on Gulf rig
NY Times: As cleanup crews struggled Friday to cope with the massive oil slick from a leaking well in the Gulf of Mexico, dozens of engineers and technicians ensconced in a Houston office building were still trying to solve the mystery of how to shut down the well after a week of brainstorming and failed efforts. They have continued to focus their attention on a 40-foot stack of heavy equipment 5,000 feet below the surface of the gulf — and several hundred miles from Houston. Known as a blowout preventer, or B.O.P., the steel-framed stack of valves, rams, housings, tanks and hydraulic tubing, painted industrial yellow and sitting atop the well in the murky water, is at the root of the disaster. When an explosion and fire crippled the deepwater drilling rig on April 20, workers threw a switch to activate the blowout preventer, which is designed to seal the well quickly in the event of a burst of pressure. It did not work, and a failsafe switch on the device also