Perched above the Waitematā Harbour, the SH18 Upper Harbour Bridge stands as a vital link. Have you ever considered the story behind this crucial piece of Auckland’s infrastructure? It’s not just one bridge, but technically two. They work together to connect Hobsonville and Greenhithe. The Upper Harbour Bridge is also called the Greenhithe Bridge.
Let’s journey back to November 1975. That’s when the original Upper Harbour Bridge was completed. It quickly became essential. However, its capacity soon proved insufficient. Traffic demands soared beyond 27,000 vehicles daily. Planners foresaw this number rising to 35,000.
To address this, a duplicate bridge was built. Construction occurred between 2005 and 2006. Beca designed and engineered the new bridge. Fletcher Construction handled the build using self-compacting concrete. The project cost NZ$35 million.
The new Upper Harbour Bridge spans 524 meters. It is 16.5 meters wide and features ten spans. Designers ensured it aesthetically matched the original. The original bridge is 457 meters long with seven spans. It is a cantilever bridge.
The bridges manage traffic flow efficiently. Three lanes head towards Greenhithe, navigating an uphill gradient. Two lanes descend downhill. Before the Upper Harbour Motorway opened, repairs were needed. Transit NZ closed the old bridge. The goal was to reduce sagging caused by old tensioning cables. The motorway opened on December 6, 2007. All bridge lanes then reopened. The new bridge also includes a cycle-way and walkway. These are located on its north side.
The Upper Harbour Bridge project received a Silver Award. The Association of Consulting Engineers New Zealand recognized its excellence. This included the causeway widening.
Here’s a surprising fact. In 1986, A. J. Hackett used the original bridge. He tested equipment for bungee jumping. This led to the world’s first commercial bungee jumping company.
The SH18 Upper Harbour Bridge is more than concrete and steel. It represents Auckland’s growth. It also stands for innovation. Next time you cross, remember its history. Think about its role in connecting communities. Think about those daring first bungee jumps.