County Concrete Right on Track as Hiawatha Light Rail Construction Moves to Next Phase
MARATHON, Wis. (June 25, 2002) - With the first underground tunnel of the Hiawatha light-rail line now complete, County Materials Corporation is currently manufacturing and shipping tunnel segments for the second tunnel beneath the Minneapolis-St. Paul International Airport. Overall, County Materials is providing 21,000 concrete segments for parallel northbound and southbound tunnels covering 3.5 miles of the 11.6-mile Hiawatha Line, which will link downtown Minneapolis, Minneapolis-St. Paul International Airport and the Mall of America in Bloomington, MN.
Since last summer, County Materials's plant in Roberts, WI, has been in high-gear production around the clock fulfilling the major precast tunnel segment contract. Segments are cast in County Materials's enclosed climate-controlled plant that protects against moisture and maintains a stable temperature. The steel reinforced precast panels have strength of 8500 psi. When bolted together on site, the segments create a huge pipe-like structure, 18'10" diameter, with a watertight seal. A total of 2,960 rings, each consisting of seven segment pieces, are being created during an aggressive 14-month schedule.
Production schedules are followed with precision as tunnel rings are erected in tandem with boring operations which run non-stop, 24-hour a day.
In mid-April, the 500-ton boring machine surfaced after completing the first tunnel beneath the airport. The second tunnel is currently underway with completion expected this September. According to County Materials's Precast Manager Dave Reneson, the operation is right on schedule. "The project has been well-planned and well-executed. The talent and teamwork of all parties involved was exceptional and we've been successful in meeting the challenges," said Reneson.
Phase two for County Concrete of the light-rail project will begin with production of wall and ceiling panels for the Lindbergh Terminal Station, one of 17 stations along the light-rail corridor in Minneapolis. County Materials will produce 108 precast arch wall panels and 108 roof panels to create a 30,000 square foot cavern, 540' long x 56' wide x 40' high. Roof panels will be bolted to the top ledge of wall segments and rock bolted to the cavern ceiling in two sections, each measuring 5' x 28'. In addition to providing structural integrity as they're constraining the limestone walls, the precast panels have to be aesthetically pleasing since they'll be visible in the station docking areas and mezzanine. Therefore, recessed areas on the surface will provide architectural character.
The mass panels will ship by rail and be moved into the cavern by crane. In what's expected to be a two-month process, production and installation will begin this October. The station will open for service in late 2004.
County Materials also helped construct other key areas of the light-rail system including airport piers to support the people mover at one of the airport's busiest concourses, and sound walls along Highway 55's Hiawatha Corridor.
With over 55 years of industry experience, County Materials is the upper Midwest's solution for premium building, construction and landscaping products. It continues to add new and innovative concrete solutions, facilities, equipment, services, and locations throughout Wisconsin and Minnesota. Headquartered in its founding city of Marathon, Wisc., County Materials currently owns and operates 14 facilities and HomeScape Studios. The Prestress, Precast & Pipe Division of County Materials Corporation is headquartered in Roberts at 1203 70th Avenue.
For more information, please call 800-426-1126.