Construction

Napier Port has established a protected breeding, monitoring and research centre for kororā, or little blue penguins, that nest in and around the sea walls at Napier Port.

Using trained handlers, Napier Port will use the sanctuary to move any penguins that are nesting in the sea wall where 6 Wharf will built when construction begins. We plan to start relocating the penguins in January 2020.

Napier Port has established a detailed Avian Management Plan, which includes a penguin action plan to ensure we protect the on-port kororā population. Longer-term we believe the sanctuary will help boost the regional population of the kororā, a nationally at-risk species.

Read more about our sanctuary here.

Napier Port appointed HEB Construction Limited as the main construction contractor to undertake the build. Construction of 6 Wharf is scheduled to start in early 2020 but before this, HEB will be establishing the construction site and securing construction materials.

Heron Construction & Dredging Limited are the key subcontractor that will undertake the essential dredging works, which are scheduled to begin in mid-2020. Read more in our announcement here.

The port is currently working with HEB Construction, undertaking preliminary work (procuring materials such as concrete and pile casings) and establishing the construction site.

Before we start construction of the wharf we need to remove some rock from the existing revetment (approximately 200 metres) to make way for our temporary shore protection (steel sheet piles).

Any remaining revetment rock will be removed prior to piling as construction proceeds.

Construction will start subject to remaining building and administrative consents, which the port expects to receive before construction is due to commence.

The wharf will be supported by nearly 400 bored reinforced concrete piles, which include permanent steel casings, fastened into the underlying competent Mangaheia group sandstone.

Piles are typically 900mm in diameter, increasing to 1200mm along the rear edge of the wharf. Piles are arranged on a typical grid spacing of 6.5m longitudinally and 5.95m transversely. The piling will be split into two operations. To begin with, the two rows that run along the landside of the wharf will be installed. This will be land based. The remaining piles will be installed over the water.

The greatest construction noise from the development is associated with driving in wharf piles. However, the predicted noise levels will meet with the daytime construction noise limits at the closest residential receivers.

We’ll be managing construction noise through hours of work and also a number of other noise mitigation strategies, which may include:

• Using vibro methods where practicable (as opposed to hammer) to reduce impact piling
• Adjust the time of day and the duration of the activities to fit within 0730-1800
• Fitting of silencers on the rig engine
• Fitting engine covers
• Regularly inspect and maintain equipment to ensure it is well oiled and lubricated.

So ships can use 6 Wharf we need to create a berth pocket to a depth of 13 meters and create a slope underneath the wharf where the shore protection will be placed.

We also need to deepen and create a larger swinging basin (where ships turn), dredge parts of the inner harbour and deepen a shipping channel closest to the port 12.5 metres deep.

This stage involves dredging and disposing approximately 1.3 million cubic metres of dredged material.

We have produced a number of management plans to mitigate against any potential adverse effects of dredging:

• Dredging and Disposal Management Plan
• Water Quality Management Plan

• Biosecurity Management Plan

Throughout the dredging campaign, we’ll be monitoring the water quality (turbidity) in real time and showing the results on our environmental dashboard. This information will allow us to constantly manage and adapt our planned dredging operations to ensure the water quality falls within expected levels.

Through a Marine Cultural Health Programme with mana whenua and a Fisheries Liaison Group, we’ll also monitor and report on water quality as well as other areas of interest.

The wharf deck will be made of concrete and constructed on ‘falsework’ – a temporary structure used in construction to support a permanent structure until its construction is sufficiently advanced to support itself.

This falsework will be supported by the steel casings surrounding the completed piles.

A corbel will be connected to the casing, which will support the falsework on sand jacks, so that the falsework may be removed later. The falsework will be decked out with plywood. The joints between the piles will be sealed, to prevent any concrete slurry dripping into the ocean. Once the formwork is in place, the reinforcing will be placed. Any block outs will then be formed, and the concrete deck poured, using a concrete pump and ensuring that no cold joints form.

The deck will be wet cured for a minimum of 7 days. Bidum cloth or hessian will be placed to cover the deck and kept wet for 7 days. Depending on the time of year, a thermal blanket may be placed over the bidum to insulate the deck during the initial stages of the curing process. The deck forms will be left in place for at least 7 days. Validation tests will be completed to confirm that the concrete has achieved maturity.

Once the deck has been poured, and temporary works removed, the precast fender panels will be lifted into place, and supported on a temporary platform, which will also provide a working platform.

This involves installing bollards and fenders on the wharf.

This involves ground strengthening work to prevent liquefaction behind the wharf.

Installation of new underground services and levelling of the pavement.

Providing their are no significant weather-related delays or other unforeseen circumstances, we plan to have 6 Wharf ready to use by the end of 2022.