November 15, 2001

Head and shoulders above Sea-Tac

  • Air traffic control tower is a blend of community, science, mathematics and art
    URS Corp.

    Rendering by Bill Evans
    Sea-Tac Airport’s new state-of-the-art air traffic control tower will open in 2004.

    The next time you drive into Seattle-Tacoma International Airport, you may think that construction of the new airport air traffic control tower is just about complete. But, that’s not quite the case.

    Substantial completion of the exterior of the tower is scheduled for late fall 2001. However, on Nov. 1, FAA electronics specialists began the 18-month process of installing the intricate communications and electronics equipment that will allow air traffic controllers to track and communicate with aircraft.

    Commissioning and testing will follow, and the new control tower is scheduled to be in use by mid-2004.

    The process

    In fall 1999, the FAA hired URS Corp. to design the “Gateway to the Pacific Northwest” project on an ambitious schedule. URS is a worldwide engineering and architectural design and construction services firm with operations in the Seattle-Tacoma area for more than 100 years.

    The URS and FAA team shared a common goal: To develop a design reflecting the motifs, themes and colors seen in the culture, skies and rain forests of the Pacific Northwest, using local materials and technology during construction, and creating a welcoming visual impression.

    “The final design is a monument to integration of the highest level of architectural design, science, technology and engineering,” says URS project architect Coral DeWilliam. “The planning and design of this highly-visible FAA facility was implemented through a successful partnership between government, the community, the Port of Seattle and the design team.”

    Through URS’ careful project management, as well as the exhaustive efforts of the project team, the FAA’s aggressive schedule was met. Architectural design efforts were equally matched with creative thinking about how to bring together the facility’s many complex technology-based building systems.

    The site

    The site was chosen by the FAA from more than 30 alternatives at Sea-Tac Airport, which were studied and assessed for size, location, orientation, radar screening and runway vistas. The benefits of the selected location include its proximity to terminal entrance roadways and the superior visibility of the runways from the site.

    With a goal of meeting air transportation needs for the next 50 years, the URS and FAA team researched and implemented an overall design that demonstrates advanced thinking for architecture, structures, communications, security and radar. The facility consists of the tower, a base building that houses support infrastructure and administrative personnel for tower operations, and an engine generator building.

    The control tower

    The tower’s exterior features a shaft constructed of pre-cast concrete panels, topped by an oval wineglass bulb of fiberglass-reinforced panels, and a pneumatically-placed concrete roof enclosure. The east face is punctuated by a translucent, indented, luminous glazed panel that serves as a backdrop for flags from the United States, Washington State and Canada.

    The Level 5 tower has a cab at more than 200 feet above the runways. In order to provide a 360-degree view from the cab, the elevator terminates two floors below it, and a retractable hoist provides a lift to the upper levels.

    Air traffic controllers have critical responsibilities requiring high levels of attention, so URS’ ergonomic design became an integral part of the cab.

    Because good visibility can be the difference between life and death, the layout of the cab was carefully planned. Comfort requirements were solicited from air traffic controllers, with several design scenarios given in-depth consideration. Finally, a full-scale mockup was constructed in which air traffic controllers were able to test out the proposed environment.

    Animated computer modeling, blast testing and wind tunnel testing were used to refine the structural design. A geometrically complex steel framework outlines the wineglass shape at the top, and incorporates moment connections of the highest degree of engineering technology. To lighten the structure’s weight and to prevent radar reflectivity from the metal reinforcement, fiberglass reinforced panels were selected to clad framework above the shaft.

    The base building

    URS created the base building’s asymmetrical lines for functionality and visual effect, particularly for those entering the airport.

    Seen from the road at night, a thin band of light will showcase the offset planes of the building’s east wall. The pre-cast concrete exterior shell has carefully placed horizontal joints and bands of smooth and scored textures reflecting the essence of the structural and force protection elements of the building.

    Reverse inclined glazed canopies protect the north and south entries, and are framed by sloped metal ribs.

    The control tower and base building are connected by a two-story glazed bridge structure. Interior organization, form and color were at the core of the project’s architectural theme.


    This project is the culmination of a process combining community input with FAA requirements for specialized engineering to achieve a grand architectural composition. It was developed step-by-step with community brainstorming; the development of shapes and systems concepts; engineering specialty systems for structure, electronics and communications; and testing for wind shear and blast protection.

    As each engineering system was developed, it was incorporated into the architectural design of the facility for optimum functioning. The resulting composition attests to a successful process involving community, science, mathematics and art.

    Michele Shamshiri is a program manager with the Facilities Architecture Group in the Seattle office of URS.

    Other Stories:

    Copyright ©2009 Seattle Daily Journal and DJC.COM.
    Comments? Questions? Contact us.