From planning and building the enormous facilities required to host the games, to the comprehensive infrastructure development needed to support the influx of visitors and vehicles, the 2012 Summer Olympics in London offers a wealth of innovative new ideas likely to influence engineering, design and construction for years to come.

Hosting the Olympics is one of the most difficult projects a city and a nation can undertake, requiring years of careful planning and collaboration among engineers, designers, builders and the international community. The 2012 Summer Olympics in London is no exception, showcasing many creative solutions to the challenges of staging a global athletic competition in a major urban area.

According to the United Kingdom’s Royal Academy of Engineering, the Olympic Delivery Authority (ODA), which was responsible for constructing the main facilities for the games, adopted six key principles to guide the project: legacy; health, safety and security; sustainability; equality and inclusion; employment and skills; and design and accessibility.

Before any large-scale construction could begin, 1.4 million square meters of the site had to be cleared and more than 200 buildings were demolished, with 90 percent of their materials recovered for reuse in the new construction project. The contaminated soil at the site also had to be cleaned and recovered. Two million tons were treated, primarily through soil washing, and 95 percent of the soil was recovered and reused as material for backfill, drainage and embankments.

The Olympic Stadium itself is a model of design and engineering versatility. Unlike earlier stadiums, the arena built for the London Games is intentionally unglamorous, and this simplicity is a key feature of the lightest, most flexible and most sustainable Olympic venue ever built.

“Olympic stadiums have typically been grandiose palaces of concrete and steel, built to last forever — even if their original purpose doesn’t last longer than two weeks. Beijing’s Bird’s Nest is designed to last for 100 years, but London’s is proud of its temporary nature. Even the bolts holding the steel together aren’t covered up, since they’ll just be removed anyway,” Popular Science explains. “But the designers had to make sure the structure had all the benefits necessary to keep the playing conditions perfect for the athletes. By using wind tunnel testing, computer models and unique fabrics, the temporary stadium for the London Olympics plays like a permanent structure — even though it’s anything but.”

Designed by U.S.-based architecture firm Populous, the finished stadium is 3,000 square feet in circumference but uses only 10,000 tons of steel, compared to 42,000 tons used in Beijing’s Bird’s Nest. It seats 80,000 spectators during the games, but will be scaled back to 25,000 seats to serve as a sports and community events venue after the Olympics are over. Its base level is composed of low-carbon-dioxide concrete, containing 40 percent less CO2 than regular concrete.

Designers created a roof with a compression truss system, which is common in bridges that rely on limited materials and must harness compression forces to give strength to the overall structure. The system surrounds the stadium with tubular-steel components connected to an interior cable-net ring with steel cables. This holds a special polyvinyl chloride-coated polyester fabric that serves as a cover. The result is a roof that can be easily dismantled, making the stadium a modular structure that can be adapted for numerous future uses.

At a price of $785 million, London’s Olympic Stadium cost about half that of a top-tier football stadium in the U.S. Part of the reason for the low cost was that designers focused on the “legacy” principle, which meant that long-term, post-Olympics functionality had to be kept in mind while building the initial stadium. The same idea holds true for the many other Olympics facilities.

“Plans for the future are in place: The media center is set to be turned into a high-tech office building expected to provide employment, and the athletes’ village will become a mix of subsidized and free-market housing,” the Associated Press explains. “Commuters, meanwhile, will rely on the many new transit links that provide fast service to many parts of London.”

Engineers also employed innovative methods for providing power and utilities to the Olympics site. An electrical substation was used to tap into the 120,000-volt electrical network outside the Olympic Park, stepping down the power to 11,000 volts to supply venues and buildings, according to the Institution of Engineering and Technology. Over 100 miles of electrical cables were installed in massive tunnels built under the park, allowing 52 pylons and a considerable amount of wires to be removed from the surface and clearing the way for construction.

To manage power consumption and distribution, the developers built a 15-story, state-of-the-art energy center that features five massive cooling towers and two 60-ton hot water boilers. In all, over 150 miles of utilities channels were installed across the Olympic Park, including nearly 100 miles of communications ducts, five miles of drinking water networks and over six miles of heating and cooling systems.

Transportation and crowd management were major concerns in the lead-up to the games. The engineering team performed innovative dynamic modeling of the crowd and traffic movements using a series of simulation models, and developed a design to coordinate bridge, highway and pedestrian movement for maximum efficiency. Their solution was to build temporary bridges and specialized at-grade crossings that could be modified to provide either a straight crossing path or a staggered one to accommodate a busy highway environment.

“Technical innovation was necessary to fully assess the complexity of the problem, test the robustness of the design solution and make clear recommendations to the ODA,” the London 2012 design and engineering innovation program explains. “Traditional modeling approaches were not adequate. An improved best practice approach was developed to integrate the assessment of highway and pedestrian conditions. This provides a benchmark by which future similar pedestrian crossing assessments may be considered.”

Despite the scale and scope of the project, the Olympics infrastructure was built within budget expectations. To accomplish this, developers adopted an integrated and comprehensive procurement plan.

“The impact and likely level of achievement in each policy area considering time, budget and practical constraints was debated in depth. The result was a widely endorsed procurement policy that focused on best value in each tender rather than cost. The assessment of best value was built around the use of a balanced score card,” the Royal Academy of Engineering notes. “The procurement code then became an operational ‘bible’ which ensured a consistent treatment of areas such as evaluation criteria, contract terms and performance metrics all based on the balanced scored card.”