You might not think it’s possible for a ship to carry 75,000 tons of cargo at once, but it is. Dockwise’s cargo ship Blue Marlin is a huge ship that can move oil rigs, aircraft carriers, and even other cargo ships. The Blue Marlin has been asked to do some big jobs, like bring the Navy’s USS Cole back home and bring an Australian aircraft carrier from Spain all the way back to the South Pacific continent.
The size of the ship is, of course, huge. It’s 712 feet long and 138 feet wide, and its deck is as big as two soccer fields (or football fields, for our foreign friends)! For such a monster to move, it needs some pretty powerful engines. Multiple diesel engines that add up to 17,000 horsepower can move the ship through the water at speeds of up to 13 knots. The Blue Marlin is also not easy to steer. Imagine trying to drive a car that’s as big as a whole office building.
How do you load cargo ships onto the deck of a ship that is even bigger?
When it came to figuring out how to load cargo onto the ship’s huge deck, the ship’s builders had to be pretty creative. After all, most of the things being moved on its deck are too heavy for even the largest cranes in the world to lift. To solve this problem, engineers came up with a new way for the ship to work: it can partly sink underwater so that its cargo can float on top of it. The crew then empties the ballast tank to bring the huge ship back up to the right height for travel.
The Blue Marlin took 22 barges from Korea to Rotterdam on one of its more recent trips. Engineers added special cradles to the ship so that it could carry the unusual load. The barges were then stacked (up to four high) before being floated onto the deck of the Blue Marlin. But this isn’t even close to being the ship’s biggest order. At one time, the carrier had to move the BP Oil Rig Thunder Horse, which is the largest offshore production platform in the Gulf, 16,000 miles from Korea to the Gulf of Mexico.
At the beginning of 2013, Dockwise bought the Vanguard, which is the biggest semi-submersible heavy lift ship that has ever been built. The Vanguard’s deck is 70% bigger than the Blue Marlin’s and can carry up to 110,000 metric tons of dead weight. The cost of the Vanguard was $240 million.