Engineering the Impossible

Cities Inside a City Engineering the Impossible focused on three incredible, yet physically possible, engineering projects: the 170-story Millennium Tower, the nine mile (14 km)-long Gibraltar Bridge, and the 4000+-foot-long Freedom Ship. Millenium Tower Imagine a skyscraper almost twice the size of the Empire State Building. This colossus would be a city within a city, hosting its own hospitals, schools, and a range of entertainment and retail options large enough to attract and keep the traffic necessary for the financial success of such an endeavor. Stats:Height: 2,755 feet, 170 stories Resident Population: 52,000 Elevator Traffic: 100,000 people per day Location: Hong Kong Harbor Closest Living Relative: Petronas Towers, Kuala Lampur (1,483 feet, 88 stories) Construction Duration: Approximately 10 years Cost: $10 billion Beyond the physical challenges of building the tallest skyscraper in the world, it will only be successful if it attracts residents, tourists and offices. The Mi llennium Tower needs to offer many choices to make it a destination of choice. Residents can go to not just one grocery store, but many.Office workers can browse a few clothing stores on their level or the same amount 30 floors up. Tourists can find the movie they want in at least one of the many theaters available. Designers say Millennium Tower will house as many options as you'd find in several city blocks. Construction of the Millennium Tower will include traditional building techniques, that, in this case, will put ironworkers thousands of feet in the air to place 5-ton girders with a minimum of safety gear. But engineers are planning to also use a new technology — building by computer.The Self-Rising Factory is a set of computerized cranes and lifts surrounded by a weatherproof enclosure. According to a precise schedule, the steel beams are essentially handed to the machinery which then places them for workers to bolt together. Once the beams and concrete panels for eac h floor are complete, the machinery hoists the entire structure and the process starts over. Gibraltar Bridge A bridge spanning 9 miles over the Straits of Gibraltar at the entryway to the Mediterranean would be the longest and tallest ever built.It would connect cultures of Christianity and Islam and potentially increase ties between the economies of Europe and Africa. Stats: Location: Strait of Gibraltar. Links Spain and Morocco. Length: 9 miles, Two spans of 4 1/2 miles each Height: Each tower is 3,000 feet tall (twice as high as the world's tallest skyscraper) Width: 5 traffic lanes, 2 breakdown lanes in each direction Road Deck Material: Fiberglass Length of Wire Cables: 1,000,000 miles (Enough to circle the Earth almost 30 times) Closest living relative: Akashi bridge in Japan, world's longest suspension bridge at 12,828 feet.Cost: $15 billion Dangers: Wind speeds of 80 mph at tops of towers, ship collision, ocean currents, traffic, Sahara Desert dust storms Building a bridge the size and configuration of Gibraltar Bridge is usually protected by artificial islands so that ships run aground before they can do any damage to the structure. But building an artificial island in the ocean isn't an option. Instead designers envision a ring of underwater bumpers to withstand ship collisions. This could be impossible to span a 9-mile bridge but actually, they can.When determining the exact size of the bridge, designers had to choose between a shallow area that spanned 20 miles, which would have meant many piers in a busy shipping zone, and a narrow portion that's 2,700 feet deep. But designers lucked out. After closer inspection of the narrow portion revealed an underwater â€Å"mountain† in the center that could hold the center piers, dividing the bridge into to spans of 4 1/2 miles each. 5 lanes of traffic in either direction will flow over a roadbed made of spun glass.Fiberglass materials of this sort are rated 5 times stronger than concrete, and any cr acks or other damage could be isolated due to its web-like internal structure. Engineers say fiberglass bridge materials can last up to 100 years. They're also easier to install. A concrete roadway on the Gibraltar Bridge would take 3 months to pour as opposed to a few days or weeks with fiberglass. Freedom Ship Freedom Ship's designers originally planned to create an island community to provide Hong Kong-based businesses a place to relocate if the handover of that city to China were to make life difficult for them.When they applied the same model to a moving sea platform, they ended up with what would be the largest ocean-going vessel ever constructed — the minimum requirement for a city at sea. Stats: Length: Approximately 1 mile Width: 3 city blocks (4,320 feet) Height: 25 stories Weight: 3 million tons Volume: Titanic, Queen Mary, USS Nimitz and super-tanker Jahre Viking would all fit comfortably inside. Population: 50,000 residents, 15,000 workers, 20,000 visitors/day Co nstruction: Hull composed of 600 120'x100†² steel cells bolted together.Location: Circles globe every two years Closest Living Relative: Japan's Megafloat Airport, Tokyo Bay (1km long, 70 meters wide, 20 meters depth) (Series of interlocking pressurized steel boxes) Power: 100 electric podded propulsers at 3500 horsepower each. Cost: $9 billion Freedom Ship's designers say it will be able to handle tidal waves and large-scale hurricanes by steering out of their way to avoid them altogether. If a confrontation is unavoidable, they'll turn all of the ship's 100 propellers, pointing towards the center of the ship for stability.The ship's hull is composed of 600 huge air-tight steel boxes. A significant number of these would have to be punctured before residents noticed anything amiss. Freedom Ship's designers call it a floating sea platform. In simliar design, Japan's MegaFloat airport id built out of steel boxes bolted together to form a surface on the water. Whereas the airport is moored to keep it from drifting, Freedom Ship would be mobile. A structure this size couldn't be built in a traditional manner at a shipbuilding facility and subsequently be lauched into the sea.The construction on this project would instead take place in the water, with large pieces floated out to be attached on the site. Freedom Ship's designers aim to create a new lifestyle. Residents will have a homelife while constantly traveling. The ship would be like a â€Å"Disneyland† offshore, entertaining tourists with the amenities of a resort while residents enjoy daytrips in each port. If successfully built The Freedom Ship will be the largest ocean going vessel in history, it will become a luxury city afloat travelling the world.