Slingshot, Ski Lift, or Rollercoaster?

What makes the new Bay Bridge look like a medieval catapult or antique roller coaster? It could be that the bridge design is based on a single, super-strength tension cable that is threaded up and around the only support via a ski-lift pulley system. According to Bart Ney, Caltrans spokesperson, this self-anchored suspension (SAS) bridge design is the first of its kind, so hauling the cable required a novel approach. Why not use a ski lift? Smart engineers never reinvent the wheel. Caltrans began work on the $6.416 billion project in 2002 and recently announced that the bridge will be completed on time, by Labor Day, 2013. Meanwhile, the existing Bay Bridge is being retrofitted for improved seismic stability, as is the case with the San Mateo-Hayward, the Richmond-San Rafael Bridge, the Carquinez Bridge, and the Benicia-Martinez Bridge, among others. The Golden Gate Bridge is undergoing similar reinforcement, although that project is being directed by the Golden Gate Highway, Bridge, and Transportation District.

Sources: (content) BayBridgeInfo.org, (photo) Mercury News, (video) BayBridgeInfo.org, YouTube