UPPER HARBOUR BRIDGE

The 'Upper Harbour Bridge' is a motorway bridge (technically two bridges as of 2006), which spans over a reach of the Waitemata Harbour and connects Hobsonville (in Waitakere City) and Greenhithe (in North Shore City), New Zealand. It is also an important connection for State Highway 18, which will become even more important once the Western Ring Route is finished (likely to be in the next decade).
The original bridge was built in the 1970s. This proved insufficient for modern traffic demands of over 27,000 vehicles per day ^[1], and a duplicate bridge was constructed next to it. The new bridge was designed and engineered by Beca, and built between 2005-2006 by Fletcher Construction using self-compacting concrete.^[2] The new bridge cost approximately $30 million and provides a 524 m long, 16.5m wide, 10 span crossing. This was designed to match the existing 457 m long existing 7-span cantilever bridge aesthetically. ^[3]
Both bridges together will provide three lanes towards Greenhithe (an uphill gradient) and two lanes downhill. At the moment (2006), Transit NZ has closed off the old bridge to make repairs, especially to reduce a sagging effect due to old tensioning cables. When the the Greenhithe motorway upgrade is completed (which is scheduled for 2007-08), all lanes will be reopened. ^[4] The new bridge also provides a cycle-way and walkway on the north side. ^[1]

Contents

References

References

1. Work on Upper Harbour Corridor Begins (official website of the Parliament of New Zealand)
2. Upper Harbour Bridge datasheet (from the New Zealand Concrete Society website)
3. Upper Harbour duplicate bridge (from the Fletcher Construction website)
4. 'Get Moving' column - ''New Zealand Herald'', Tuesday 06 June 2006
5. Work on Upper Harbour Corridor Begins (official website of the Parliament of New Zealand)