After 3 days at sea the base of the Perdido arrives at the oil field. The crew get ready for the next stage of the operation, to install the bottom half of the rig, called the spar. They face the mammoth task of upending 18,000 tonnes of steel. The engineers release the air from the floatation tanks, then pump seawater into the bottom end of the spar. This flips the whole structure into an upright position, so they can begin the process of attaching it to the ocean floor, thousands of metres below.
Instead of driving impossibly long steel piles, the engineers at Perdido use ropes and chains to hold the rig in place, but they need something to secure the ropes on the seabed, so they attach huge metal cylinders to the end of the ropes. Once these cylinders, called suction anchors, reach the sea floor, the engineers use clever physics to drive them deeper into the ground.
Suction anchors are the perfect solution for anchoring deepwater offshore platforms like Perdido. But activating a suction pump at the bone crushing depths below the rig is impossible for human divers, so the engineers use robotic divers, called ROVs, to do the job. An operator kilometres away manoeuvres the ROV towards the suction anchor and attaches a pump. This removes the water and creates a vacuum that sucks the anchors down and locks Perdido’s foundations into the seabed.
Clip from the “Big Bigger Biggest” documentary series exploring the engineering breakthroughs that have enabled us to develop some of the largest structures in existence.
Watch the complete documentary here - • Oil Rigs - Technologic...
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Almost impossible? So they fail?
Thanks for uploaded