Media Release

21 January 2013

Lower Hatea River Crossing components arriving

Major components of Whangarei’s Lower Hatea River Crossing arrived in Whangarei today.

The deck of the bascule and pieces of the huge J-beams that will form the bridge’s distinctive hook-like profile arrived at Marsden Point from China on Monday, and two 9.5-tonne hydraulic rams that will lift and lower the bascule (lifting platform) are making their way by ship from Holland.

The rams have been manufactured by Eaton Hydraulics in Eindhoven, Holland, as part of a package of hydraulics works that was awarded in association with local firm McRaes Global Engineering.

The rams are double acting, which means they will be used to control both the lifting and closing of the bascule. Cylinders will extend to raise the bascule and will retract to lower it. The rams will be controlled with valving in the pier and powered by a power unit on the western embankment.

When raised, the uppermost point of the bascule will tower 40 metres above average high tide.

Whangarei District Council Infrastructure and Services Manager Simon Weston said the powerful rams have a normal operating force of 80 tonnes, but they will be able to raise the 400-tonne bascule section because 140 tonnes of counterweight in the end of the J-beams helps gravity do some of the work.

“We are making good progress and looking forward to the opening ceremony in July,” said Mr Weston.

“This month the last bridge beams and precast concrete deck sections will be installed on the bridge, along with bridge handrails and the concrete footpath on the Pohe Island side of bridge. The Okara Drive roundabout will be completed and work will continue on the Pohe Island road, drainage works at the Riverside Drive roundabout, and electrical installation.”

When the system is up and running it will work this way

To ensure smooth traffic flows during peak hours the bridge will be closed (the bascule will be down) between 7.15am and 8:45am and between 4pm and 5.30pm.

The bascule will only be raised outside peak hours, and only at the request of skippers who will ring or radio a request to the bascule operator.

On average there are about six vessel movements each day through the area spanned by the bridge, which will require the bascule section to lift. Most vessels that don’t have masts will be able to pass under the bridge when the bascule is down, because there will be 7.5 metres between the average high tide and the underside of the bascule section.

When the bascule is being raised

When the bascule is being raised the situation will be managed in a way similar to a railway crossing.

Signs on Riverside Drive, Port Road and Okara Drive will warn drivers that the bascule is lifting, giving them the options of waiting for the bascule to open and close or using a different route.

On the bridge an alarm will sound, lights will flash and a barrier will drop to stop cars and pedestrians from going onto the bascule.

The bascule will rise (this takes about 90 seconds) the vessels will sail through (expected to take one or two minutes depending on the number of vessels and how fast they are moving) then it will take another 90 seconds for the bascule to come down. The total wait time is expected to be five to six minutes.

The barriers will then rise and traffic can flow through.
ends

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