SH21 Narrows Bridge Hamilton to be closed for one day


The NZ Transport Agency (NZTA) advises that Narrows Bridge, which crosses the Waikato River just south of Hamilton on State Highway 21, will be fully closed to traffic on Wednesday 20 April to remove the temporary bailey bridge.

NZ Transport Agency (NZTA) State Highways manager Kaye Clark says the highway will be closed between the hours of 9:30 am and 5:00 pm.

The road closure is required to remove the bridge which was installed to enable embankment strengthening to take place.

People travelling to Hamilton International Airport on SH21 (Airport Road) from the Tamahere side of the city are advised to allow approximately 30 additional minutes for their journey.  The recommended route to and from the airport during the removal of the bailey bridge, is via SH3 (Ohaupo Road). Detour signs will be in place.

Mrs Clark says the Narrows Bridge itself is structurally sound, however the soil nailing undertaken beneath the bridge was required to strengthen and stabilise the adjacent Waikato River banks.

It involved drilling around 75 holes in each bank, 100mm in diameter, to a depth of 18 metres. Once the holes were drilled a reinforcing bar was installed in each one and the hole filled with cement grout. Following completion of the soil nailing to both banks, the faces of the river banks were covered with concrete to protect them and prevent further erosion as river levels rise and fall.

In preparation for the bailey bridge removal work, a two hour stop/go operation will be in place on Monday 18 April 2011 from 4.30am, to enable marking of the Narrows Bridge back to two lanes.  Motorists may experience minor delays during this time.

Please see attached files for suggested alternative routes.