When it comes to rebuilding Terminal C of the Raleigh-Durham International Airport, “bigger is better” could easily be the theme for the project. The features of the new terminal will include larger concourses with 32 gates, more airline ticket counters, more baggage claim areas and a larger security checkpoint.

But the most impressive feature of the new Terminal C will be the record-setting glue-laminated wood truss system that will make up the roofs in the concourse and terminals. According to Project Manager Joe Thompson, the system is the largest using glue-laminated wood trusses in the United States.

“This truss design has never been done,” Thompson says. “With the engineering that went into this thing, it is the first of its kind. The cables are essentially as large as they are for proportional reasons. It required unique and difficult engineering because the forces in the truss make the thing difficult to engineer. But the engineers on the job did a phenomenal job.”

Archer Western, the general contractor, is working on the first phase of the project, which includes demolishing the existing terminal and concourses. The first phase will be completed in summer 2008, and Phase 2 will be done late 2010. When the project concludes, Terminal C will expand from 330,000 to 890,000 square feet, from four to 10 lanes for security checkpoints and from three to five carousels for the baggage claim area. Thompson says the cost of construction is $360 million.

Global Materials
For the complex truss system, Archer Western used materials from numerous countries, according to Thompson. The glue-laminated wood members and the steel came from Canada. The steel cables were made in the United Kingdom, but they were spun and cut to length in Germany before arriving at a plant in Indiana that attaches connection pieces to the ends. The system was prefabricated in China and put together on site. Thompson says the company had to look overseas for some of the materials because American vendors haven been inundated with orders for projects in hurricane-ravaged areas. “Hurricanes and all that has occurred here in the states has increased the workload for many manufacturing companies here,” Thompson adds.

With materials coming from so many locations abroad, Archer Western had a crash course in international purchasing, according to Thompson. “We learned about international purchasing and how to best handle that in the future,” he adds. “There are differences in dealing with overseas purchases.”
    
Complex System
Because of the complex nature of the truss system, Archer Western employed the services of a peer review structural engineer, who reviewed the erection plan and made sure nothing had been left unturned in terms of caring for materials and the safety of the workers. “I had never used it before, but it was worth the extra energy and effort,” Thompson says.

“With the direction of these trusses, they came in pieces and we had to assemble them here on site,” Thompson adds. “The erection contractor developed a lifting table, where the truss was assembled on its side. For a truss, that is its weak direction. It was lifted in a vertical position, hinged on one crane, to lift truss off the table and set it into the space.”

Another issue Archer Western came across for the truss system was the difference in tolerances between the wood and steel used for the roof. Thompson says the wood has a very precise tolerance, while the steel had a larger tolerance than the wood.

But the company recognized the differences during preplanning and made the adjustment before it became a problem. “At the beginning of the project we recognized it, so we had to adjust to how we were doing things for tight tolerances,” Thompson says. “We adjusted the steel manufacturing to support that.”

About Archer Western
Archer Western is a general contracting, construction management and design/build firm established in 1983 in Illinois. Today, the company is a subsidiary of the Walsh Group, which is ranked among the nation’s top 20 contractors by the Engineer News-Record. The firm performs as an open-shop contractor and is an expert in various building, civil and transportation sectors, including wastewater and water treatment plants, rapid transit, highway and bridgework, educational facilities, warehouse/distribution facilities and office, according to the company.

“In all of its years of construction operations, Archer Western has never failed to complete a contract,” the company adds. “The company has invested over $300 million in capital equipment and employs over 1,000 engineers and skilled tradesmen.”