The 65ft-long (20m) sections of the curved pedestrian bridge were designed and fabricated in the maximum dimensions possible to lift with Central’s crane fleet.
Planning for the bridge construction began in summer 2007, with groundbreaking following in September. Danny’s Construction Company, Inc. (DCCI) of Gary, Ind., the steel erector, hired Central Contractors Service, Inc. of Chicago to supply cranes for the project.
Rich Linsenmann of DCCI worked with Paul Urbanski of Central. Linsenmann says: “Paul was integral in recommending the correct crane configuration as a part of the DCCI erection plan.”
The Monroe Street/Art Institute section of the Bridgeway is composed of four curved-bottom structural steel sections.
“The site is particularly tight and required exact dimensional layouts to allow for erection of the bridge elements. Many times the clearances between the building, the crane, and the bridge were within 1 foot,” says Linsenmann. “Central met the challenges as we expected they would.”
John Martello, Central Contractors Service general manager, says, “Setting these heavy steel segments across Monroe Street, on a rising plane ending 60 feet in the air at the entrance to the museum addition, was a challenging undertaking because of the tight clearances. The crane had be positioned as close as possible to the bridge to achieve the desired operating radius of 79 feet.”
The GMK 7550 was specced with 52ft (16m) of main boom and 132 US tons of counterweight.
Central is a member of the ALL Erection & Crane Rental Corp. family. The pick was planned with the assistance of ALL’s Compu-Crane 3D lift simulation software. Compu-Crane drawings, in conjunction with CAD drawings, were used to ensure that this would be the right choice of crane for the project, thereby increasing efficiency and safety and reducing cost.
Like a runway from the heart of Chicago’s Millennium Park, the Nichols Bridgeway spans Monroe Street to the third-floor level of the Art Institute’s new Modern Wing, currently under construction.
The slender bridge, just 15 feet wide, has a curved, white-painted steel underside resembling the hull of a boat or a racing shell. The floors will feature textured aluminum planking, and the bridge has views of Millennium Park, Michigan Avenue, and the lakefront. Both the museum addition and the bridge were designed by architect Renzo Piano. Both the Modern Wing and the Bridgeway are anticipated to open in spring 2009.