Extreme Engineering

The Turning Torso is the world's largest residential structure, rising 190 meters above Malmö, Sweden.

Venice floodgates Fact file When built: Started 2003, completion due 2010 Height: 30m Weight: 300 tons each Timescale: Seven years Construction material: Steel Number of barriers: 79 Capacity: Stop tides of up to 2m In 1900, St. Mark's Square in Venice flooded about 10 times a year. Now water covers it 100 times a year. Global warming is causing sea levels around the world to rise and environmental experts believe Venice may well go the same way as Atlantis. In September 2003, work began to prevent the city’s 45km of canals from cannibalising its ancient architecture. Phase one saw dredging machines begin to remove 3.8 million cubic metres of clay from the lagoon bed at the mouth of its three inlets. This is being replaced with 9m tons of rock and concrete to provide a sturdy foundation to fix the 79 steel floodgates. Each is bigger than a football field and weighs over 300 tons. When not in use, the gates will lie flat against the lagoon floor. At the threat of a high tide, hydraulic valves can be opened at the flick of a switch allowing the gates to pivot into position. At a cost of $3 billion, the project isn’t exactly cheap. But then, it’s less than the estimated losses during Venice’s worst ever flood in 1966.

Covers the docking of a container ship at Long Beach (California) and the operation of the water front docks, where several thousand containers need to be unloaded and loaded in 48 hours. Also covered is the building of the Adrian Maersk, the world's largest container ship. While the scale of these gigantic ships has to be seen to be believed, the construction must be precise to millimeters.

Imagine driving across a bridge near the North Pole, or going from New York to London in just an hour through a tunnel under the Atlantic Ocean. These are just some of the awe-inspiring projects of today's builders and engineers. Jaw-dropping computer animation illustrates the largest, most outrageous projects ever conceived. As students learn about stretching the boundaries of modern engineering, they also gain understanding of the technological design process and come to understand how physics and chemistry are utilized to solve modern human engineering challenges.

Fifty years after the idea of harnessing the frightening force of Iceland’s glacial rivers was first conceived, the vision is about to be realised. Around 200 miles northeast of the capital, Reykjavik, engineers are hard at work drilling 72km of tunnels deep in the mountains. Three full-face boring machines (TBMs), have been specially shipped from the US to this remote site, 100 miles south of the Arctic Circle. In fact, one has just completed work on a new subway route in New York. Manufactured by American tool company, Robbins, the TBMs each measure 7m in diameter and weigh over 80 tons. Digging an average of 25m a day, each TBM needs 3 megawatts of power to drive it. Other sections of the tunnels will have to be excavated by explosives and power tools. The tunnel’s purpose is to guide water to the valley floor from reservoirs that are also currently under construction. The cascading water will drive six turbines, each with a rated output of 115 megawatts. With a total capacity of 690 megawatts, it will be the biggest hydropower plant in Europe. The project completion is scheduled for 2009.

Engineers redesign oil platforms to withstand the harsh weather conditions in the Gulf of Mexico.

Connecting the bustling port city of Charleston and Mount Pleasant in South Carolina, the Cooper River Bridge will be the longest cable-stay bridge in America. Spanning 490 metres across a busy shipping lane, the bridge has to be built of sturdy stuff. But the biggest threat to its survival is nature. Not only is the structure standing on one of the most seismic spots on the East Coast, it also faces the frequent threat of 300kmph hurricanes. The engineers faced a very tall order – especially with a relatively low budget of $531million. The mainline structure will accommodate eight 4m-wide lanes of traffic, separated by a central barrier. The road deck itself is suspended 54m above sea level by 128 individual cables, strung in parallel from the diamond-shaped support towers. Cable-stayed bridges consist of one or more pillars located in the middle of the span, with cables supporting the roadbed. In this case, each cable is capable of holding 500 tons. To protect the cables from changing weather conditions and moisture they’re enclosed in high-density polymer pipes. Rock barrier islands have been built up around the support towers to prevent ships from careering into the bridge. Plastic hinge zones are being built into towers to allow flexibility during an 8.0 magnitude earthquake. In addition, a damping system has been developed to ensure the structure can withstand hurricane-force wind. The Cooper River Bridge is designed to remain in operation for the next 100 years.

This episode examines the quest to build the world's highest bridge as part of a major highway connecting Paris with Italy and Spain.

In northern Minnesota, the operators of the world's largest open-pit iron mine commission the construction of a $10 million custom-built super-shovel in the hopes of making excavation more efficient.