Bridging Inspiration- Zaha, Calatrava and SRG Partnership

Portland firm SRG partnership is keeping some very good company in the March issue of Architectural Record. In a long continuing-education feature devoted to pedestrian bridges, SRG’s design for elliptical span at Seattle’s Museum of Flight is one of three projects featured, and the other two are by a couple of the most famous architects in the world: Zaha Hadid and Santiago Calatrava (both of whom should be considered for the Columbia River Crossing).

The Seattle branch of SRG, headed by Rick Zieve, FAIA, came up with the $6.4 million bridge design, which is intended to mimic the forms of jet plane contrails.

As Joann Gonchar writes in Record, “The bridge’s primary span is a 200-foot-long tube truss, about 17 feet in diameter, tapering to about 12 feet at the ends. SRG had originally hoped to make it out of pipe sections bent into ellipses…[but] the architect came up with a more cost-effective and buildable alternative: The webs are
made up of two sets of 5-inch-diameter pipes bent into pure
circles."

The more than 300 bent pipes are inclined in opposite directions to overlap, giving the bridge an elliptical section even though its individual elements have a simpler geometry. Although none of these pedestrian bridges have the same program or scale as the three Portland bridges going through design right now—the Columbia River Crossing, the light rail & pedestrian bridge on the Willamette, or the reconstructed Sellwood Bridge—but they should serve as a reminder of what great design can bring.


If we are willing to select bridge designers with great talent and not just a track record of building other bridges, and if we’re able to craft a public process that not only gets them in place but allows them creativity, this will be the route to bridges we can all be proud of. Sure, the amount of lanes matters. So do budget and sustainable design principles. Even so, the design is what will last for generations even as other factors from the time of construction fade away.






Article by Brian Libby on 03/09/2009
Images obtained from: archiblog.info