Northport, Marsden Point
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Client: Northland Limited
Location: Marsden Point
Contract Value: NZ $31 million
Completed: Jun 2002
Main Contractor: Fletcher Construction

 

Northport is a new deep water port developed at Marsden Point, primarily to handle the rapidly increasing Northland log harvest.  The project comprised a new 400 metre long wharf and a 32 hectare reclamation.

Sheet Piling

The work involved driving 3,000 tonne of sheet piles for the wharf outer wall and associated tieback wall.  The outer wall length was 400 metres and consisted of 30 metre long sheets, AZ36 section, driven 18 metres into the sea bed.

The outer wall was restrained by 326 tie back anchors, 56mm diameter connected to the tie back wall of 7.5 metre long AZ26 sheetpiles.

Wharf Piling

The wharf structure piles consisted of 130 steel tube piles (710mm and 610mm diameter), driven to depths of 20 metres into silt and coarse sand seabed conditions.

Concrete Deck Structure

The concrete wharf deck, 390 metres by 16 metres, was poured in 24 metre long sections utilising an innovative travelling form.

Harbour Dredging

1.7 million cubic metres of sand was dredged from the harbour to provide the deep berthage required and to reclaim the necessary wharf area.  Dredging was performed by subcontractor Heron Construction utilising their cutter suction dredge.

Environmental Factors

The joint venture instituted numerous successful initiatives including

  • use of bio-degradable hydraulic oil
  • numerous decant systems and silt control curtains
  • careful selection of appropriate pile driving hammers resulting in a commendable environmental record.