When the platform is complete in 2017, this piece – the gravity-based structure – will create the platform’s solid base. The base is so solid, in fact, that it alone spans 130 meters in diameter… 20 yards longer than an American football field.
But how do you design and build something that large?
Answer: very carefully. Long before it was constructed, the platform was planned to exacting specifications. The gravity-based structure (bottom) and topsides (top) of the platform are each designed using state-of-the-art modeling to perform flawlessly and protect the environment in tough iceberg-prone, deep-water conditions.
It doesn’t stop there, though. With something this big, even the building site requires careful design. The Hebron gravity-based structure started life in a dry dock in Great Mosquito Cove, 150 km (93 miles) northwest of St. John’s in Newfoundland and Labrador, Canada. First, the engineers had to create the dry dock by building a wall and pumping the water out from behind it. Once the structure had reached the limits of construction in the dry dock, water was pumped back into the dock and the 180,000-ton structure was floated. Yes, concrete floats – when built to displace water like a ship. Then they removed the wall and towed the structure to a deep-water site 3 km away to continue construction.
At the end of the video, the platform is not yet complete. It still needs to be joined – or “mated” – to the topsides, which is the most commonly seen part of a platform. When both the base and top have been added, tugs will tow the structure 350 km (218 miles) to the Hebron field, where it will be one of several offshore facilities producing oil in the Jeanne d’Arc Basin.