Watch: New video on $3.4b City Rail Link, works move up Albert St

A new film on New Zealand's largest transport infrastructure project shows work beneath the historic Central Post Office/Britomart transport hub and up Albert St where some initial tunnel phases are almost complete and progress moves up the busy city road.

Work on the Government/Auckland Council joint venture City Rail Link has now moved up Albert St towards the Mayoral Dr intersection, outside the SkyCity Grand, partially closing part of that upper end of the road.

The new video shows where tunnels have been dug from the surface, the trenches excavated from above and the tunnels built through those deep cuts. The trenches are then back-filled and the surfaces reinstated.

The next major stage of tunnelling via a tunnel boring machine below the ground is yet to start.

Just before Christmas, the project reached a milestone with the breakthrough from the Albert Street tunnels to CRL tunnels under Commercial Bay, Precinct Property's $1b 39-level tower, now being clad in glass.

Workers in the video are shown on scaffolds receiving, placing and fixing reinforcing steel, pouring concrete, building formwork, directing cranes and placing goods being lifted into the trenches.

The twin tunnels with their wall separation along the track section are shown but work has not yet started building Aotea Station where those tunnels will meet for the first time after Britomart.

Work is moving up Albert St. Photo / Dean Purcell

At the C2/Lower Albert St contract, city workers pass by hoardings which shut most of Albert St in restricted vehicle entry. The site approach is filmed, followed by portions of completed tunnels yet to get tracks but with tunnel sides formed, along with floors and roofing complete.

Work is also shown in other less advanced phases which remain open to the sky.

The project, due to open in five years' time in 2024, is developing two 3.45km tunnels at a maximum 42m beneath the ground, although many parts are not that deep, linking Britomart with Mt Eden and eliminating the cul-de-sac which now terminates all train journeys at Britomart.

But CRL is warning not to make a common mistake about its project. The L in the name trips up people the most.

"It's not a loop as some have described it," the joint venture says.

The L stands for 'link'.

"Think of it like the Waterview Tunnel which joined up Auckland's motorways. This does the same with the rail lines. CRL will connect with the Western Line at a redeveloped Mt Eden station and so open up the entire rail network."

As for the total project completion cost, that remains up in the air. Some say the $3.4b project has blown out by $500m to $1b but nothing has been confirmed.