In tandem with Port Otago’s channel deepening project, the berths where the container vessels sit are also being deepened. To safeguard the wharf structures ahead of the deepening work, a row of “sheet piles” are being driven along the berth line, essentially an underwater retaining wall as shown below.
The work is being undertaken over a two year period, to ensure there is one operational container wharf at all times. Container Berth No 1 (container wharf closest to Port Chalmers township) has been completed while the outer Container Berth No 2 (Multi-purpose wharf) is expected to be completed in 2018. The outer container wharf will be closed to all vessels between May and mid-October 2018, coinciding with the low export season and before the commencement of the cruise ship season.
With the sheet pile wall in place, the deepening of the berths can proceed in line with the channel deepening project.
The current construction of both container wharves feature a piled wharf structure with a revetment, or rock slope, underneath the wharf which supports the reclamation and container yard behind. This slope is stable with the current berth depth of 13m but the necessary deepening required to cater for larger ships means Port Otago must safeguard the wharf structures by driving a row of “sheet piles” along the berth line, essentially an underwater retaining wall as shown above.
In order to maintain one working container wharf at all times, Port Otago has split the construction project over two years with the Container Berth No 1 (container wharf closest to Port Chalmers township) being completed in 2015 and the outer Container Berth No 2 (Multi-purpose wharf) completed in 2018. The sheet piling can’t be undertaken while vessels are at the berth meaning that between May and mid-October 2018 the outer container wharf will be closed to all vessels. This timing coincides with the low export season and also ensures completion before the commencement of the cruise ship season.
While the wharf is closed to vessels it is also an ideal opportunity to upgrade the rubber fenders on the wharf. These fenders (or buffers) protect both the vessel and wharf from damage during vessel manoeuvring. The upgraded fenders are larger and more suitable for the much bigger container ships now plying their trade through Port Chalmers.
Consents are in place for this work, with the primary environmental effect being construction noise. To comply with the consent held, work must comply with the New Zealand construction noise standard (NZS6803: 1999) with pile driving work only taking place between the hours of 6.30am and 8.00pm Monday to Saturday inclusive.
A detailed description of the current work:
The relevant consents can be found on the Consent Documents page, in particular consents 2010_200_v1 and 2010_197_v1 apply.