<http://schema.org/articleBody>
"  1. IN THE DERRICK A top-drive motor in the 160-foot derrick can apply 25,000 foot-pounds of torque to the drill string. The rig can drill through 20,000 feet of rock.  2. HULL GEOMETRY The Kulluk is 24-sided, nearly round, and flares out below the waterline. The shape helps it shed ice but makes the rig hard to tow.  3. SPREAD ANCHORS The Kulluk is anchored above the well by a dozen 3.5-inch-thick lines. In an emergency, these can be released with an acoustic signal. 4. MUD-LINE CELLAR Vital well components are positioned in a 40-foot-deep, 20-foot-wide cavity (a mud-line cellar) to protect them in case a huge iceberg passes over the site. 5. DRILLING SO FAR In 2012 the Kulluk drilled to 1090 feet below the rig floor and cemented 30-inch-diameter casing to a depth of 330 feet. In 2013 the company hoped to reach potential oil-bearing layers thousands of feet deeper. 6. BLOWOUT PREVENTER A failed blowout preventer (BOP) was a big factor in BP&amp;#039;s Gulf of Mexico spill. The Kulluk&amp;#039;s BOP has three mechanisms (pipe rams, blind-shear rams, and annular valves) to shut off the well. A capping stack can also be placed on top of the BOP.    &amp;amp;lt;&amp;amp;lt;&amp;amp;lt; One Troubled Rig...    "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.popularmechanics.com/science/energy/a8750/anatomy-of-an-offshore-oil-rig-15152665/>