Kia ora and welcome to the Autumn 2019 update from the Transmission Gully team.

In the three months since the last project update, we have made great progress with much of it being structures focussed.

The traffic switch at Pāuatahanui gives road users a chance to fully understand the sheer size of the new road as they drive under the bridge that will eventually carry State Highway 1 traffic.

At Linden, we are in the process of lifting beams onto the bridges over State Highway 1, a logistically challenging piece of work which drastically changes the landscape for rad users and gives a real sense of how this significant piece of road will function once completed.

They are exciting times for everyone involved and we look forward to sharing progress with you as we move towards completion.

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Paving the way for a major project milestone

Transmission Gully Motorway paving

Sections of the 27km long Transmission Gully Motorway are ready for pavement construction and then final surfacing.

Transmission Gully’s 27km main alignment will hit another significant milestone in coming weeks when pavement construction begins in the southern part of the project. The process of constructing pavement involves the placement and compaction of the many layers of aggregate that make up the base layers under the final road surface.

Project Director – Construction Justin Redelinghuys said the commencement of pavement construction on the main alignment indicates just how far the project has progressed.

“It is an exciting visible indicator of progress. The sense of achievement for everyone involved when pavement construction starts is immeasurable. We are one big step closer to completion,” Justin said.

Constructing the pavement for the entire 27km stretch of road is a substantial task and will require over 680,000 tonnes of high quality aggregate, most of which will be sourced locally and transported in more than 25,000 short-haul truckloads over the coming year.

“The pavement construction programme is scheduled to tie in with completion of earthworks so that stretches of road are laid as the earthworks in that section are finished. The first pieces of finished road to be constructed will be the stretch between SH1 and Bridge 20 Over Cannons Creek, and 7 kilometres through Battle Hill Farm Park,” Justin said.

The top 400mm of road surface for Transmission Gully will be made of a high-quality cement treated aggregate. After the aggregate is placed, a surfacing layer is placed over the aggregate to help waterproof it and provide a wearing surface for the road.

After the surface layer is placed, the road is ready for the finishing touches of line marking and the installation of barriers and reflectors.

Once the pavement construction in the southern end of the project is complete, the construction team will focus on the northern section in April and then the central section south of SH58 in May. Pavement construction work will continue until the completion of Transmission Gully in 2020.

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WorkSafe praise for Transmission Gully’s health and safety culture


Transmission Gully’s health and safety culture is having a positive effect on the Wellington region.

Transmission Gully Project’s approach to health and safety is being applied on other construction sites in the Wellington region, according to WorkSafe Technical Specialist Rob Birse, who visited the site recently.

Rob said that he had observed improved site management and health and safety practices when carrying out assessments for new subdivision earthworks.

“Feedback from site managers was that they had previously worked on the Transmission Gully project and were keen to continue using the Transmission Gully approach to health and safety,” Rob said.

“One of the benefits of large projects is that there is an opportunity to embed systems with workers and contractors that can be transferred to other worksites. This is a very positive outcome.”

Wellington Gateway Partnership CEO Sergio Mejia said one of the over-arching goals of the project is to leave a positive legacy – and the feedback from WorkSafe shows that while safety is a journey we are moving in the right direction.

“We make a concerted effort to upskill the workforce and instil a workplace safety culture. We want every person who works on the project to return home safely every day. Nothing else is acceptable,” Sergio said.

WorkSafe NZ statistics support what Birse has observed, with Transmission Gully’s health and safety performance above industry standards, a result that Sergio believes “reflects the Project team’s commitment to best practice”.

By the numbers

The Health and Safety at Work Act 2015 (HSWA) requires that WorkSafe is notified if someone has been exposed to a serious and immediate risk of harm because of a workplace incident.

In 2018 WorkSafe NZ recorded 418 notifiable incidents from the construction sector. Transmission Gully, one of the biggest construction projects in the country, has experienced six notifiable incidents since May 2015.

Transmission Gully Project Safety, Health and Quality Manager, Rod Ladyman sees the numbers and recent praise as useful insights.

“The team will continue to aim for H&S excellence through the “exhibition of chronic unease” and I encourage all other workplaces to do the same,” Rod said.

Transmission Gully working collaboratively to improve health and safety

Transmission Gully, represented by Wellington Gateway Partnership, is one of a group of major capital works projects that are collaborating to help lift the sector’s health and safety performance.

The group also includes representatives from the Puhoi to Warkworth and City Rail Link projects, along with the NZ Transport Agency, Zero Harm and Construction Health and Safety NZ (CHASNZ).

The group recently kickstarted their collaboration with a workshop focused on sharing their experiences and learnings, including identifying the key challenges they have confronted in the H&S space.

Wellington Gateway Partnership CEO Sergio Mejia said that major capital works bring a wealth of health and safety experience into the local industry.

“It’s important that the upskilling of workforce that occurs on major projects is retained long after project completion. The collaboration is a step forward in this direction – ensuring that valuable learnings are captured and applied for the good of the sector,” Sergio said.

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Working with iwi to form strong partnerships

Southern end of the Transmission Gully Motorway alignment.

To honour Ngāti Toa involvement in the Transmission Gully Project, an iwi artist has been commissioned to create a unique piece of artwork which will be placed on the southern end of the alignment.

The strong partnership between the Transmission Gully team and Ngāti Toa Rangatira will culminate in an art wall along Transmission Gully at SH1 in Linden.

Transmission Gully’s Stakeholder Manager Darren Utting said working with and including key stakeholders in decision making for Transmission Gully has been the cornerstone of the project’s progress, and none more so than local iwi Ngāti Toa Rangatira.

“To honour and acknowledge Ngāti Toa and their extensive involvement in Transmission Gully, an art wall designed by a Ngāti Toa artist will be installed along SH1 in Linden before the completion of Transmission Gully,” Darren said.

“Ngāti Toa were very open to having early, productive discussions with us about the impacts of Transmission Gully on their rohe (region), whenua (land) and taiao (the environment) and it was important to us that we understood the cultural and historical significance of key areas on the Transmission Gully route, to ensure that we treated those areas with the utmost respect.”

Executive Director for Te Rūnanga O Toa Rangatira Tā Matiu Rei said Ngāti Toa Rangatira has been involved in the Transmission Gully project since September 2015 when a Memorandum of Understanding (MOU) between CPB HEB JV  and the iwi was established.

“The MOU between the builder  and Ngāti Toa Rangatira was the first component to forming strong partnership, but true partnership lies in the implementation of that MOU,” Tā Matiu said.

Within the MOU, CPB HEB JV and Ngāti Toa Rangatira agreed to:

  • Follow agreed protocols for archeaological or cultural finds
  • Follow agreed protocols prior to and during the diversion or reclamation of any streams and waterways
  • Provide opportunity for appropriate ceremonies around a range of events throughout the project construction

CPB HEB JV also consult Ngāti Toa Rangatira on any changes to the project, additional consent requirements and provide opportunities for the iwi to be involved in urban and landscape design work and naming new or existing landmarks along the Transmission Gully route.

“Rūnanga staff and kaumātua and kuia often represent iwi interests and provide advice and consent on resource management,environmental impacts on streams, waterways, traditional walkways and historically significant lands, archeological finds during excavation and earthworks and cultural practices,” Tā Matiu said.

“The art wall will be a visibile representation on Transmission Gully of our relationship with the project and it is an exciting opportunity for the selected Ngāti Toa artist.”

Darren said submissions for the artwork were sought from iwi artists and designers, with selection of the preferred design to be judged by a panel consisting of kaumātua, NZ Transport Agency urban designers and the Transmission Gully construction team.

“The brief to potential designers was to create a piece of art work that was both relevant and significant to the area, and that would not cause undue driver distraction,” Darren said.

The shortlisted designs are currently being taken to the engineering team to determine the best way to translate the design from paper to the wall; a complex process that needs to ensure the wall not only looks good but is also future proofed for longevity.

The date for the design unveiling has not yet been decided.

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Transmission Gully gets involved

The sheer scale of the Transmission Gully project means that it touches on many communities both in terms of local employment and physical impact.

Transmission Gully Community Relationships Manager Belinda Mackenzie-Dodds says it is a goal of the Wellington Gateway Partnership that the project builds positive relationships with the communities that are impacted by construction work.

“We recognised that due to the 5-year construction period we needed to build positive community relationships to try and offset the negative impact that construction can have in those communities. One of the ways we do this is by getting involved in community events and initiatives,” Belinda said.  

“It’s incredibly rewarding to be working with a team who really want to make a difference in their area.”  Located at the heart of Transmission Gully’s main site office at Lanes Flat on SH58, the Pāuatahanui and in particular the Pāuatahanui School is one community group that the project team has worked with closely.

Belinda Mackenzie-Dodds

Community Relations Manager Belinda Mackenzie-Dodds speaking about the project at one of the many community events that the Transmission Gully Team attends.

The Transmission Gully team have been involved with the school since the start of the project. The Project has had a stand for the last 4 years at the Pāuatahanui School Lamb and Calf Day, the school’s main fundraising event, as well as donating plants to the annual Potty Planters plant sale. The project team  was also able to assist with removing some unwanted old trees and resurfacing in the playground area.

At the southern end of the project, the team has been working with Linden School, right beside the Collins Avenue overbridge. As well as being involved in fundraisers, the project also donated the resources to demolish old playground equipment.

Over summer, the Transmission Gully mobile information centre was located at Battle Hill Farm Park to give campers at the popular spot a chance to learn more about the work going on in the heart of the park.

In January the park was the venue for two major events, Battle Hill Farm Day run by Greater Wellington Regional Ccouncil (GWRC) to showcase the working farm’s activities, and Eat Drink and Be Crafty, a fundraising event run by the Lions.

The Transmission Gully team were on site for both events to chat to people about the project and were blown away by the level of interest.

As well as working with schools and attending community events, Belinda often gives talks and presentations to schools and interested community groups such as Probus Clubs and Residents’ Associations. She says that this is one of the best parts of her job.

“I thoroughly enjoy the opportunity to engage and interact with community groups and provide more detail about the benefits of Transmission Gully in their communities,” Belinda said.

Wellington Gateway Partnership CEO Sergio Mejia states that being a good neighbour underpins all we do with our community.

“We do our best to keep people updated through our quarterly newsletters, regular letter drops and information flyers to residents about localised works happening in their area. We’ll continue to do this and attend local community events, until the project is complete.”

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Bridge beams lifted over State Highway 1

Beams being placed onto the northbound on-ramp Linden in October 2017

A beam is lifted into place over State Highway 1 earlier this month.

Transmission Gully progress on SH1 Porirua – Linden is ramping up again, and this time our focus is on building bridges.

Throughout March and April, the Transmission Gully team is lifting and placing bridge beams across the SH1 connection to Kenepuru Drive in Porirua, the northbound flyover connection on to Transmission Gully, and the middle section of the new Collins Avenue overbridge in Linden (near Tawa College).

It’s an exciting time for Wellington and although full completion and ‘tie in’ to the Transmission Gully motorway is still some time away, the works planned over the next six or so weeks is a significant milestone for the construction of the motorway.

Each bridge beam weighs approximately 58 tonne (58,000kg). There are 24 bridge beams for the two bridges that span over SH1 and an additional five bridge beams for the Collins Avenue overbridge. This means that there are 47 beams in total to be lifted and placed over the next two months.

On Thursday 12 March we commenced work to lift two beams on average into place per night. This work impacts on travel through the area between 7pm and 5.30am on week nights.

To ensure the safety of road users and staff while we lift the bridge beams, there is an altered lane layout. We are regularly implementing a ‘contra flow’, where all traffic is moved onto one side of the motorway, while the other is free from traffic. This is so that road users are not travelling below bridge beams that are in the process of being secured.

During this time, we may also occasionally need to hold back one direction of SH1 traffic for up to 15 minutes.

The diagram of a contra flow below shows what you can expect when this altered layout change is in place.

With construction now commenced, the area is already starting to look a lot different and could be distracting for some drivers. Please drive to the conditions and the posted speed limits.

More information including the timeline for the works and traffic management will be available on our Traffic notices page: www.nzta.govt.nz/tg-traffic-notices

For live traffic updates, travel times, traffic cameras, incident and roadworks information, visit the Wellington Journey planner page: www.journeys.nzta.govt.nz/wellington(external link)

For regular real-time updates follow @NZTAWgtn on Facebook(external link) and Twitter(external link)

Contra flow example

This diagram shows what you can expect in a contra flow layout.
View larger image [JPG, 580 KB]

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Construction progress

Sometimes a picture is worth a thousand words. Here are some of the latest photos for key areas of the project.

Mackays Crossing and Paekākāriki Interchange

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Mackays Crossing and Paekākāriki Interchange

Work continues on the main alignment in between old State Highway 1 and the temporary realignment.

Mackays Crossing and Paekākāriki Interchange

This aerial photo shows how Transmission Gully Motorway will connect in with the existing SH1.

Wainui Saddle

Wainui Saddle

Looking to Kāpiti from the top of the Wainui Saddle.

Wainui Saddle

Benching across the hill at the top of the saddle. Machinery in the foreground give a sense of the size of these benches.

SH58 and Pāuatahanui

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SH58 interchange

Traffic moving along the new layout of SH58 at Pautahanui. When the project is complete Transmission Gully Motorway will pass over the bridge in the centre of the photo.

SH58 Interchange aerial

Looking north, this photo gives an idea of the main alignment route between SH58  Interchange at Lanes Flat and Battle Hill Forest Farm Park.

James Cook Interchange

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James Cook Interchange

Work on the James Cook Interchange is now well underway. The link road connecting over the hill to Waitangarua is visible in the background.

Bridge 20 over Cannons Creek

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Bridge 20 aerial over Cannons Creek

Crossheads are nearing completion ready to receive the bridge structure as it inches its way across the gully.

Bridge 20 girders

Bridge girders are lined up ready to be attached to the structure as the launching process continues.

Linden/Tawa and Collins Avenue SH1 bridges

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Bridge 26

Beams will be lifted at night onto this, and two other bridges during March and April.

Linden/Tawa Bridge 26

View from the road showing two of the beams in place.

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Construction milestones

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Mobile information centre visits Porirua

Mobile visitor centre outside Pātaka Art + Museum

The Transmission Gully mobile visitor centre on-site at Pātaka Art + Museum.

Looking for the Transmission Gully information centre? Head to Porirua where you will find it located next to Pātaka Art + Museum for the next few months, after which it will move to Kāpiti in May.

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Keeping you up to date

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We hope you enjoy reading these updates, and we’d love to hear from you. If you have any questions, comments or story suggestions, you can email them to info@tg.co.nz.

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