Deep below the central city, up to 44m at Karangahape Rd, the construction phase of the City Rail Link has reached an important milestone. The civil works are nearly done and dusted and the outcome has the look and feel of the London Underground.
MC30, the name of the twin tunnels and three new stations snaking 3.4km from Britomart to Mt Eden, has largely been built without mishap - if you exclude Covid delays and years of disruption to small businesses, hotels, apartments dwellers and visitors to downtown Auckland.
Below ground is a different game, says Barry Potter, an engineer with a beaming grin who has worked on big projects around the world and, these days, is Auckland Council’s eyes and ears on the $5.5 billion project, for which ratepayers are picking up half the tab. The Government is paying the other half.
He’s referring to the vast concrete shell of the flagship rail project with its subterranean stations and 200m-long platforms that will add more than three times to the capacity of the rail network in stages over the coming decades.
When the CRL opens, hopefully sometime in 2026, patronage will rise from 15,000 passengers per hour to 27,000 and Aucklanders will be able to whizz from the central city to Mt Eden, via Karangahape Rd, in about 10 minutes. Over the coming years, the new rail line and nine-car trains will be capable of carrying 54,000 passengers.
On a tour of the project last Friday with Potter and City Rail Link boss Sean Sweeney, the Herald saw just how far one of New Zealand’s largest and most complex projects has come since the first sod was turned in 2016.
The tour began at the Mt Eden site, where two years ago the giant tunnel-boring machine, named Dame Whina Cooper, rumbled under the motorway network from Spaghetti Junction to Albert St in downtown Auckland. Twice.
There, a new station, with a featured water wall and Māori motifs carved out of concrete panels, is taking shape. So, too, a tall building with huge fans to pump air through the tunnels.
The 10ha site is still a busy construction zone with walls of scaffolding above the tunnel entrances, piles of concrete railway sleepers and rubber pads ready to be laid in the tunnels, and noisy wackers compacting soil to backfill the land.
Once construction is finished and the site is remediated, the vacant land will be packaged up and sold for apartments and commercial development on a scale not dissimilar to Wynyard Quarter.
In Sweeney’s words, the area circling Mt Eden and Eden Tce will become a rail version of “Spaghetti Junction” with trains running in all directions.
Next week, the first train will enter the first section of the rail track at Mt Eden, carrying 75m lengths of rail towards Karanga-a-Hape station to extend the tracks to Te Waihorotiu station, the biggest of the new stations below Albert St.
The tunnels are made of concrete panels fixed in place by the tunnel-boring machine, the shape of a round roof, the floor flat with a carved-out channel in the centre acting as a drain for any water that gets in.
The tunnels are wide enough for an emergency walkway and work is progressing on installing overhead power, sleepers, tracks, and trays for hundreds of kilometres of cabling.
Rail geeks have something else to get excited about. On the wall panels are a series of numbers at regular intervals. The numbers are a signpost of how far the railway line, forming part of the national main trunk line, is from Wellington. For example, the number 684 stipulates a distance of 684km.
Likewise, the MC30, MC20, MC50, and M60 names given to different sections of the CRL tunnels are railway jardon. Once the project is handed over, the names will change to more friendly language.
As the tour approaches deep beneath the Karangahape Rd ridgeline, the vast size and scale of the project become apparent. It’s here where 100,00 tonnes of spoil have been removed to create two caverns for the 203m platforms with entrances up to 44m below ground at Mercury Lane and Beresford St.
The station is a maze of concrete pillars and beams, daylight peeping through and a gang of skilled workers brought in from overseas twisting and turning the final cable ties to hold the steel reinforcing together for the last concrete pour on one of two platforms.
The complexity of the work underground, getting materials and people in and out through a giant hole in the ground at Mercry Lane, is really big stuff, says Potter.
“The day-to-day, week-to-week, month-to-month planning of how the work is going to be delivered and resourced is quite incredible,” he said.
Sweeney said the site was starting to feel like an underground station, saying there will be radical change over the next nine months as the bare concrete is replaced by painted walls and the complex work of installing the software, signalling, and integration with the existing network begins.
But already the long platforms, arched walkways between the north and south rail lines, and space for the largest escalator in the Southern Hemisphere have the look and feel of the London Underground, Paris Metro and New York subway.
It’s hard not to be blown away by what lies beneath, let alone the architectural designs and sculptural forms that will emerge at the re-named stations.
Te Waihorotiu station, with entrances on Victoria and Wellesley Sts, is equally impressive with a single wide platform with tracks on each side. The station overshoots Albert St as far as Wyndham St and Mayoral Drive and will become the city’s busiest station with a second, wide level for circulation.
The first entry point to the station is in place with views down Wellesley St to Chris Booth’s “Gateway” sculpture at the entrance to Albert Park.
At Wyndham St, the tunnel changes from the round shape laid by Whina Cooper to the square-sided “tunnel box” running all the way to Britomart, renamed the Waitematā Railway Station.
This was the first, and the most disruptive, section of the CRL to be laid when work started in 2016, causing years of misery for businesses caught up in a “war zone” along Albert St.
It took the Government years to establish a fund to support businesses suffering financial and mental anguish, and then it excluded many only metres outside the zone still impacted by the dust, dirt, and high fences which kept customers away.
The heartache was the result of the construction method known as cut-and-cover, which involved digging a trench, lining it with concrete piles, bracing it with steel wales, and pouring a concrete shell into it. For many months, the old Post Office building at Britomart was closed and held up by pillars to make the connection between the old and new.
Today, it’s a seamless connection, and down the track will draw more passengers and options for getting around the city.