Master tunneller and engineer Francois Dudouit is a marathon runner - appropriate, given the scale of the project the Frenchman heads in Auckland.
The civil engineer of Vinci Construction Grands Projets is project director of the Link Alliance, which in 2019 was appointed to build stations and tunnels for New Zealand's largest infrastructure project, the $4.4 billion City Rail Link.
Given the long-distance runs he loves, patience and endurance is paramount in his role.
"In the past year, we've done a lot of work which is just not so visible but by the end of this year, the project will look a lot different to what it does now," he says from the alliance's headquarters at 12 Morgan St, Newmarket, off Carlton Gore Rd.
He's referring to the big leap forward CRL will make this year when the Chinese-built German-designed tunnel boring machine (TBM) begins its round-trip Mt Eden-CBD journey.
Sitting in the alliance's headquarters, in what were Tegel's offices before they moved to a new Mansons TCLM building, the quick-witted multi-lingual Dudouit is cracking jokes about learning Spanish when he lived in Denmark "and I didn't realise we'd have to go from Danish to Spanish".
Here, he is learning te reo Māori and making the most of travelling New Zealand in any spare time he has.
A project hallmark will be reached in a few weeks, when the TBM named Dame Whina Cooper will set off from Mt Eden and dig towards Karangahape, Mercury Lane, Beresford Square and the new Aotea Station, cutting the first ground with her giant spinning head and sharp teeth.
By September, the TBM should break through to the new Karangahape Station digging the northbound tunnel, Dudouit says.
Within a year, the TBM will return to excavate the southbound tunnel.
Karangahape Station's excavation is unique because it's the only station that won't have its tunnels dug by the machine: that tunnel needs to be so much larger than the actual machine, Dudouit explains, that the vast subterranean cavern will be created in advance, using other equipment.
The machine is 7.15m in diameter and cannot excavate beyond its size.
Karangahape will act as a through station for the machine, he says.
Once the machine reaches Beresford Square it will continue to Aotea where it will arrive later in the year. Then, it will be dismantled and trucked back to Mt Eden to begin digging the northbound rail tunnel, expected to be completed next year.
Dudouit's eyes sparkle at the thought of the accomplishment, even though he acknowledges the complexity and size of the job: "There are so many different gradient levels as well as so many different disciplines working on this project," he says, citing the 42m underground the tunnels will run at their deepest point below the city centre.
Asked how many tunnels he's built since 1986, he says it's too many to recall but he knows he has been on projects that created 50km of underground networks under some of the world's biggest cities.
His work is concentrated in some of the world's largest transport jobs.
"I've only ever worked on underground railway tunnels, except once when it was a wastewater project in Hong Kong."
Dudouit has developed a passion for New Zealand's outdoors while living here: "I've run marathons and half-marathons in Auckland, Christchurch, Hanmer Springs and Queenstown. I love it."
This year in Picton he tripped while running and broke his shoulder, leaving him strapped up for weeks so he kept fit by taking to walking, drawing pity from others - which he also smiles about.
He spent 10 years in Sweden, five years in Denmark and three years in the Netherlands.
The pandemic meant the shift to Auckland came at great personal cost.
"I haven't seen my wife in 15 months."
Delphine (Chomei) remained in Shau Kei Wan, Hong Kong, while their son Augustin,18, finished school. Around the middle of this year, the teenager will shift to Europe for university and by July or August, Delphine will move into the Parnell apartment he lives in, Dudouit says.
He is philosophical about family life sacrifices, saying his career has always been moving from one country to the next.
Dudouit does the hard stuff globally but he says Auckland's rail project is up there with the best.
"CRL is a mega project in a world sense, which makes it interesting. The work is so motivating because we have all types of disciplines here: engineers specialising in foundations, earthworks, civil and two types of tunnelling - mine and tunnel boring machine and the railway systems.
"We have around 1300 people working on the project but more than 2000 if you include subcontractors, all at Mt Eden, Karangahape Rd, Aotea and at the Link Alliance head office."
The Link Alliance integrated people from 30 countries and 16 disciplines.
He arrived in New Zealand from Hong Kong four years ago, around June 2018, initially for meetings when the Link Alliance was bidding for the contract "and I'll be here until 2024, so I'll be here for six years all up. This is a beautiful country with lots of pleasant people, never too hot or too warm."
The marathon runner now has his gaze set on the finish line three years out when CRL is complete and he moves onto the next mega job.
• 1986-1988: with Vinci on France's Villejust project, twin-bored 5km railway tunnels;
• Early-mid-90s: Denmark's Storebaelt railway tunnels, twin-bored 7.4km long with 7.7m internal diameter;
• 1995: Hong Kong with Vinci to work on the strategic sewage disposal scheme, a major tunnel and cavern job for the interception, movement and treatment of wastewater in fractured volcanic rock;
• 2000-2003: the Netherlands for Vinci's work on the Pannerdensch Canal project, building dual-rail tunnels to link Rotterdam's port and Holland's border with Germany;
• 2003-2012: with Vinci on Sweden's Hallandsas railway tunnel project, an 11km job by Skanska-Vinci, tunnels under the Hallandsas Ridge. Sweden's longest rail tunnel meant fewer trucks and cars travelling between Gothenburg and Malmo;
• 2012: Hong Kong for Vinci's unsuccessful tender on the Tuen Mun-Chek Lap Kok project, cut and cover construction of two 4.2km sub-sea tunnels, each 14m in diameter. Bouygues won that;
• 2012-2019: in Hong Kong for Vinci on the new Sha Tin-Central link, extension of the territory's rail system, building a 30m shaft at Diamond Hill. Twin tunnels 1.6km and 2.1km long in a drill and blast technique in granite rock and a two-level public transport terminal with road connection, works.
• 2019-2024: Project director, Link Alliance [Vinci is an alliance member] on Auckland's $4.4b City Rail Link, 3.45km twin-tunnels up to 42m below city centre, Britomart-Mt Eden, two new stations are Aotea and Karangahape.