Bigge Lifts Aerial Bridges at Moscone Center
The Moscone Center, San Francisco’s premier convention and exhibition complex is undergoing a major expansion that will add over 300,000 square feet of exhibition space, meeting rooms, ballroom, and support areas. Bigge was hired to perform the lift and set of a steel spine that comprises the first of two pedestrian bridges, fabricated on site and weighing over 340,000 pounds.
A pair of crawler cranes from Bigge’s fleet performed the job: a Liebherr LR 1300 SX, outfitted with 115 feet of main boom, 66 feet of luffing jib, 273,000 pounds of main counterweight, and 125,000 pounds of carbody counterweight and a Manitowoc 16000 outfitted with 118 feet of main boom, 137 feet of luffing jib, 332,000 pounds of main counterweight, and 120,000 pounds of carbody counterweight. With detailed planning and coordinated communication between the operators and the entire crew, the crawlers safely lifted the spine from the ground to a height of 45 feet.
As the span reached across Howard street, iron workers secured the structure to steel columns that integrate with an existing structure on the north side, and a new structure rising on the south. From the spine will hang supports that hold aloft a passageway, enabling foot traffic between the new South Hall expansion and the Yerba Buena Gardens.