Contracts awarded for track and systems works on CRL

Two contracts have been awarded for the delivery of works for Auckland’s City Rail Link.

Known as C5 and C7, the contracts have been awarded to delivery consortium Link Alliance and are within the existing project budget.

C5 primarily involves the connection between the new line from Britomart, via Aotea and Karangahape, to the existing line at Mt Eden. Where the CRL meets the North Auckland Line at Mt Eden, the twin track split into two branches, eastbound and westbound, said Francois Dudouit, project director for the Link Alliance.

“This requires changing the vertical alignment of the NAL tracks and partially the horizontal alignment, meaning replacement of tracks and overhead line equipment (OHLE) on more than 1km of the North Auckland line,” he said.

“It also requires retaining walls to transition from the existing NAL track level to the CRL line – a 3.5 per cent slope. More than 1,000 piles, diaphragm and sheet pile walls will be needed to build these retaining structures and the two cross-over structures to connect to the NAL upmain.”

Road and pedestrian bridges at a number of level crossings will also be built, including at Normanby Road, Fenton Street, and Porters Avenue, to improve cyclist and pedestrian safety.

The C7 contract covers the Systems Integration, Testing and Commissioning components of the CRL project. These include trackslab, track, overhead line, signalling, control systems, communications systems, control room fit-out and building work, and trackside auxiliaries. Work also includes integrating the new line and systems with the legacy systems on the Auckland rail network.

Dudouit said that work to connect the various components of the project is already occurring.

“Integration of the C5 and C7 teams into the Link Alliance is well underway across multiple workstreams including civils, programme and cost control. Early works such as utility relocations and establishing single-line running are already taking place as part of an integrated programme to deliver the City Rail Link to Aucklanders in 2024.”

As these elements of the project require involvement from various stakeholder from the current network, such as the transport authority, Auckland Transport, close working relationships have been established.

“KiwiRail and Auckland Transport, and their supply partners, are formally engaged for the City Rail Link project through stakeholder partnership agreements. On a day-to-day basis, staff from both Auckland Transport and KiwiRail work in the Link Alliance offices to maximise collaboration opportunities, as part of an established interface and relationship management programme,” said Dudoit.

Karangahape

Tunnelling works progress at Karangahape station site

Tunnel mining has begun at the site of the future Karangahape Station with a large excavator brought in to create a 15 metre long connection to the caverns of the future station.

Machinery is digging out the short tunnel from the temporary access shaft, 18 metres deep.

Dale Burtenshaw, deputy alliance director for Link Alliance said the connection would be critical.

“This connection is short, but it will become an important and busy ‘construction artery’ for us providing access for people, machines and material,” he said.

Once the 9.5 metre wide and 8m high arch-shaped tunnel is excavated a roadaheader will finish the connection before beginning to dig out the station platform tunnels.

“It’s a clear sign of work ramping up. Our focus is very much on welcoming the Tunnel Boring Machine at Karangahape Station at the end of next year on the first leg of its journey from Mt Eden,” said Burtenshaw.

When complete, Karangahape will be New Zealand’s deepest underground station at up to 35 metres underground. The station will be 217 metres long to accommodate nine-car trains.

Here the tunnel boring machine will arrive after carving out the twin tunnels from Mt Eden Station.

To ensure construction and earth mining noises are limited, a unique acoustically insulated noise enclosure will encase the access shaft.

“The noise enclosure is a bit like a silencer on a car, reducing the impact of construction at street level in a busy part of the city around Karangahape Road,” Burtenshaw said. “The enclosure muffles construction noise and gives us the flexibility to work longer hours to get the job underground done without disturbing neighbours living and working around us.”

Other work such as the installation of reinforced concrete panels are also underway along with utilities relocation. Plunge columns through the centre of Beresford Square are also beginning to be installed to support floor slabs during construction.

TBM handed over for work on Auckland CRL

The City Rail Link (CRL) project in Auckland, New Zealand, has officially accepted ownership of its tunnel boring machine (TBM).

The machine has been assembled in Guangzhou, China and after a number of tests is ready to be shipped to New Zealand, said Francois Dudouit, project director for CRL’s tunnels and stations delivery consortium Link Alliance.

“The TBM successfully underwent more than 500 tests to make sure everything works as it should. There is now great excitement that we are ready for the next step – to bring the TBM to Auckland.”

The TBM has been designed to meet the unique challenges of tunnelling under Auckland, where it will dig the tunnels, transport the excavated spoil, and install the concrete panels that will line the tunnels.

“It is a unique, world class machine – an underground factory – purpose built to carve its way through Auckland’s sticky soil,” said Dudouit. “Just about everything that moves was tested to make sure it can do the transformational job it’s been designed for.”

While the CRL project has been slightly hampered by restrictions on travel for key personnel, and the delivery of the TBM was delayed due to the factory closing in China, the successful handing over of the TBM demonstrates that the project can continue during COVID-19, said Sean Sweeney, chief executive of CRL.

“The successful factory assessment tests and the handover of the TBM to the Link Alliance is a very clear and strong indication that the CRL project can meet critical milestones in a Covid-19 world.”

The TBM will carve out the twin, 1.6km-long tunnels between Mt Eden and central Auckland where it will connect with tunnels from Britomart. Delivery is expected in October and it will begin tunnelling in April. Each tunnel is expected to take nine months to complete.

The TBM will be named in honour of Māori rights champion Dame Whina Cooper.