Helix Bridge, Seattle

Amgen, a leading human therapeutics company in the biotechnology industry, decided to access their headquarters in Seattle, Washington with a new signature span pedestrian bridge, 400’ long. The large curved pipes represent the double helix of DNA.
 
Tight erection tolerances, irregularly weighted parts and a busy train route all added to the complexity of the steel erection.
 
KWH provided erection services using a scheme with falsework and temporary stays to overcome these problems and allowed unimpeded train passage under the bridge during construction.