A New Reality

By David Einstein
Illustrations by Bechtel Advanced Visualization Group

On a big Mideast airport project, the customer got to tour the passenger terminal before it was built. In the UK, computerized simulations help determine where to place interactive train signaling on a busy rail line. At the Chornobyl nuclear power plant, engineers designed a permanent shell for the failed reactor without having to get near it.

In each case, Bechtel used virtual reality—animated, three-dimensional walkthroughs akin to sophisticated video games (except without the car wrecks and shooting)—to show in advance what completed projects look like and how they work. Since its creation in 1995, the company’s Virtual Reality Lab has created virtual worlds for a wide range of projects, including liquefied natural gas plants, airports, bridges, and rail systems. Virtual reality walkthroughs can speed up the design process, confirm engineering decisions, and even reveal design flaws that can be fixed before construction begins.

They also reassure customers that a project will meet expectations. “It’s very good to let people see what they’re going to get, let them interact with it, and build in a confidence factor,” says Carl Johnson, the 23-year Bechtel veteran who heads the virtual reality team in San Francisco.

Martin Melin, an animator and modeler who has been with Bechtel for 25 years, explains the process of creating an animated computer walkthrough or virtual video. “The first thing we do is find out if the project has any 3D data. That helps in some cases. If not, I’ll take anything—design drawings, photos, artist conceptions, even sketches on napkins—and rough up something in 3D.

“The next step is to get a list of materials that are being used [for an airport, that might include concrete, glass, and marble surfaces]. If we can get samples, we digitize them to make the textures in the virtual reality look more realistic.”

The team builds a 3D model, then animates it with techniques that can include lighting effects, multiple camera positions, and special effects such as the replication of a single tree many times to create a landscape. The completed animation is rendered into a virtual presentation by 20 computers running simultaneously. The team completes it by adding titles, transitions, and a soundtrack.

The finished product can be put on a DVD or uploaded to an Internet server that can be accessed by designers, the customer, and in some cases, the public. Users can interact with walkthrough models using a mouse and keyboard—much like navigating through a video game.

How elaborate can a virtual simulation be? It depends on what the customer wants and how much time is available for the job. “We’ve had projects run anywhere from two weeks to more than a year,” says Johnson, adding that simulations can get quite sophisticated. “We have ways to visualize computational data, fluid dynamics, and sound data that allows a person to see the unseen.”

Some of the most complex visualizations so far have been for big airports, where customers want advanced architectural designs that also meet the needs of thousands of passengers. At the New Doha International Airport, now under construction in Qatar, Bechtel created walkthroughs of the terminals, using information supplied by subcontractors. “That way, the customer was able to see the entire design in a single model instead of having to look at each subcontractor’s design separately and put it all together in their head,” says Johnson.

A full-scale virtual reality environment also was done for a big airport in Dubai—and in that case, the computerized walkthrough led to a design improvement. “The customer just wanted to be able to see how the project would look, but when they saw the presentation, they realized they were going to need better security,” says Melin.

Validating the design is a top priority for Bechtel’s virtual reality team in the UK, which is working on a number of rail projects. On the West Coast Route Modernization, for example, virtual reality simulations are letting engineers choose locations for new signals in heavy traffic locations such as the Trent Valley, northwest of London; and Rugby Station, east of Birmingham.

“By using 3D models to simulate trains running at various speeds, we can place signals in the correct locations and get earlier approval for the designs,” says Andy Codd, who heads the virtual reality team for Rugby. The station has more than 70 signals, which handle more than 120 routes.

Codd’s team has taken the 3D modeling concept a step further by incorporating a fourth dimension—time. “By being able to show how the project will look at various stages in 4D, we’ve been able to integrate planning, engineering, and constructability,” he says. As a result, design iterations can be done faster.

On some projects, virtual reality is a virtual necessity. At the Chornobyl power plant in Ukraine, the site of history’s worst nuclear accident, a Bechtel-led consortium designed the concept for a permanent shell to cover the failed reactor. To facilitate review by hundreds of parties and gain approval, Bechtel created a virtual model showing how the shell would be built and how the temporary “coffin” that has covered the reactor for two decades would then be dismantled and removed. The concept was approved.

While aiding designers and reassuring customers, virtual reality also can help a project gain public trust. Take the new Tacoma Narrows Bridge in Washington State, for example (see sidebar). “The project wanted something it could show the public, to let people know what was happening and when it was happening,” says Johnson. “So we created virtual walkthroughs for all major phases of the project.”

Ten years ago, virtual reality in the engineering and construction industry was considered a luxury. Not anymore. Advances in computers, software, and the Internet have made walkthroughs and videos cost-efficient. Today, at companies like Bechtel, they have become increasingly valuable business tools. Says Johnson: “Almost everyone who has used our virtual reality services in the past couple of years has come back to say they want more.” 

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