Exploring the 10 biggest engineering projects in the world is a study in enormous ideas ranging from transportation solutions to an oasis paradise in a once-barren desert.  Some of these projects will take you to subzero temperatures, and others will transport you miles above the Earth.  So let’s get started.



10: The International Space Station 

The International Space Station (ISS) is the largest manned object ever sent into space [source: Houston Public Television]. Picture two Boeing 747 airplanes next to each other, and that will give you an idea of the ISS’s living and working area — 43,000 cubic feet (1,217.6 cubic meters) to be exact. In fact, it’s such a large project that it will soon be visible to the naked eye from 90 percent of the Earth’s surface.

Sixteen nations, numerous corporations and 100,000 people have collaborated to pull off this stellar project. The most expensive single object and the largest space station ever built, the International Space Station has already cost the United States alone $100 billion, an amount roughly equivalent to the price tag for all Apollo missions to the moon combined.



9: Three Gorges Dam 

Some say the Three Gorges Dam was China’s largest engineering project since the Great Wall. The dam stretches nearly a half-mile (0.8 kilometers) high and spans a mile and a half (2.4 kilometers) wide, creating a reservoir big enough to bring massive cargo ships 1,500 miles (2,414 kilometers) inland. A team of 20,000 workers scheduled in round-the-clock shifts constructed the Three Gorges Dam, which was completed in 2009. More than 1.5 million people relocated to make way for the construction of the dam, and 100 towns were leveled in the process. The dam’s turbines were designed to generate nearly 10 percent of China’s electricity supply. After the dam’s completion, China continues with its post-construction plan, which includes eco-management and helping people get settled after relocation.



8: Boston’s Big Dig (Central Artery/Tunnel Project) 

Boston’s Big Dig, one of the most complicated engineering projects in the world and the most expensive public works project in the United States, finally opened in 2003, five years behind schedule and 30 years in the making. With an original price tag of around $4 billion (figure adjusted for inflation), the Big Dig ended up costing more than $14 billion. Workers constructed the Big Dig while traffic roared overhead on Boston’s main highway, Interstate 93. Giant boring machines pushed prefabricated tunnel sections below frozen earth and beneath existing underground train lines. Rearranging centuries-old gas, water, electric, phone and cable lines further complicated building a new tunnel with as many as four highway lanes in each direction. The project also included a tunnel to Logan Airport as well as a cable-stayed bridge to replace the double-decker truss bridge over the Charles River.

Admirers hail it as an architectural wonder. Ultimately, the project demolished the city’s main traffic artery that for years split city down the middle, and it created a new landscape that will one day be teeming with parks and green space.



7: Yucca Mountain Nuclear Waste Repository

There are more than 121 sites in the United States where nuclear waste is currently being stored. While some say disturbing this waste is too dangerous, others advocate for moving it to a centralized repository. And thus, the idea for the Yucca Mountain Nuclear Waste Repository was born.

Although it hasn’t stored one iota of nuclear waste yet — and may never do so — the Yucca Mountain Nuclear Waste Repository has already cost $9 million. The proposed storage site for all of the radioactive waste produced in U.S. nuclear power plants is a giant tunnel bored into the side of a mountain some 80 miles (128.7 kilometers) from Las Vegas. The United States has already spent $58 million planning its waste storage project.

But the Yucca Mountain project has been caught in legal and political limbo for years, and in February 2010, it died on the drawing table. The Department of Energy announced it would be withdrawing its application for a license to use the Nevada site, and the Obama administration vowed to redirect funding away from the project.


6: The Dubai Canal is a planned mega development that will consist of numerous shopping centers, entertainment venues, hotels, restaurants, luxury housing, public beach space, walkways and cycle paths. The project spans 3 km (1.9 miles), starting from Business Bay into the Persian Gulf through Safa Park and Jumeirah.  Construction on the project started December 2013 and is expected to be completed by the year 2017.



5: The Panama Canal.  The Panama Canal 48-mile ship canal in Panama that connects the Atlantic Ocean (via the Caribbean Sea) to the Pacific Ocean. The canal cuts across the Isthmus of Panama and is a key conduit for international maritime trade.  France began work on the canal in 1881, but had to stop because of engineering problems and high mortality due to disease.  The United States took over the project in 1904, and took a decade to complete the canal, which was officially opened on August 15, 1914.



4: Marmaray is a rail transport project in the Turkish city of Istanbul.  It’s comprised of an undersea rail tunnel under the Bosphorus Strait and the modernization of existing suburban railway lines along the Sea of Marmara.  The first phase was opened in October 2013.



3:  The New York Subway System.

Each weekday, commuters tally more than 5.2 million rides on the New York subway system, for a combined total of 1.6 billion trips annually. Today, the underground rail network operates nearly 6,500 cars on more than 700 miles (1,126.5 kilometers) of track; it’s the largest subway system in the United States. As of 2007, it was ranked the fourth-largest subway system in the world. Laid end to end, New York City Transit train tracks would stretch from New York City to Chicago. The first line of New York’s subway opened on Oct. 27, 1904, and now its 26 lines and 468 stations offer service throughout the city’s five boroughs. The transit system, which is owned by the City of New York and leased to a subsidiary of the Metropolitan Transportation Authority, operates 24 hours a day, 365 days a year.



2:  The HavvAda Island.

The HavvAda artificial island is a proposal to build a canal between the Black Sea and the Sea of Marmara. The 48 km canal, which could be completed as soon as 2023, would provide an alternative Mediterranean access route to the cluttered Bosphorous waterway, but it could also displace as much as one billion cubic meters of dirt.  The dirt displaced by building the canal would be molded into six hills on a man-made island near Istanbul. These would be supported by giant geodesic domes that form their own mini-climate and are arranged around a central core.

The island could accommodate 300,000 residents, who would enjoy a great deal less pollution, overcrowding and traffic than most city dwellers face today.



1:  Sky Cities.

Simply put, these are futuristic buildings towering above the Earth.  Theoretically, sky cities will reduce overcrowding in urban areas, and some serious architects and engineers are determined to bring fantasy to life.

In 1989, an engineering firm proposed the mixed-use tower called Sky City 1000 that would house approximately 36,000 people in residential spaces and 100,000 in its commercial spaces. A report by the Council on Tall Buildings and Urban Habitat suggests that a tower similar to Sky City 1000 could open as soon as 2030 [source: CTBUH]. Then, there’s Dr. Eugene Tsui’s vision of the 2-mile (3.2- kilometer) high Ultimate Tower, which would create 1.5 million square feet (1.46 million square meters) in which to house 1 million people. One sky city building has gone so far as to anticipate emergencies: Plans call for elevators that will hold approximately 70 people and fire drills that would involve 35,000 occupants.