Kiwi engineer, construction specialist, academic and railway boss Sean Sweeney remembers his first train trip well: from Johannesburg to Durban as a 4-year-old with his Irish parents.
They were "chasing rainbows", living on the continent where his mother had been a missionary.
The parents had migrated to New Zealand as "Ten Pound Poms" in the 1950s, but didn't initially stay. After returning briefly to Castlebar, County Mayo, in Ireland, they then lived in South Africa. Sweeney's first train ride came as they headed for Durban, to get the boat back to New Zealand. At that time, says Sweeney, this country was "a land of milk and honey compared with England where my father had lived, at the time still suffering rationing after the war".
The parents settled in Wellington. Sweeney's father was a plumber who aspired to wear a tie as a sign of class movement, and his mother was a secretary and office worker - "and dad did get to wear a tie, when he became a clerk of works".
But it's rail that has resulted in Sweeney living in Auckland.
"South Africa was the first train ride. The second was from Porirua to Wellington around 1967 when I was being taught swimming at the Freyberg Pool. That rattled along, very old coaches from memory," he says. "I'm not a train spotter. I just love really big projects of all kinds."
Those projects have involved Te Papa in Wellington; Melbourne projects including a hospital, recycling and waste centre, a stadium, the Melbourne Convention Centre; and a A$2.5b New South Wales prison construction programme.
That big project expertise landed him the role heading Auckland's $3.4 billion City Rail Link, starting as CEO on July 2 with an open-ended contract, working for the Auckland Council/Government alliance. Sweeney's job is to build the underground twin-tunnel lines and stations to provide the city's missing railway link.
That job, he says, eclipses anything else in New Zealand in terms of its size and scope. It will involve trenching and then tunnelling beneath Auckland's CBD and fringe CBD area from Britomart to Mt Eden, and is set to allow the rail network to at least double capacity.
The engineer with an Australian PhD in construction economics hasn't spent much time here in the past few years, having lived mostly in Melbourne.
With New Zealand and Irish passports, and Australian citizenship, he has a tinge of strine in his accent. His office is poised above the busy Customs St/Lower Albert St intersection, the very spot where CRL construction is active, its twin tunnels now disappearing beneath Precinct Properties' PwC Tower at Commercial Bay.
After an Auckland University degree, Sweeney spent seven years on Wellington's Te Papa before leaving for the United States and Europe. He then settled in Australia and bought a house in the leafy Melbourne suburb Camberwell, raising a family who are now also working in the construction sector.
He delivered a programme of major public infrastructure for the state of Victoria, ran construction for one of Australia's biggest builders, Grocon, and lectured in construction management at Melbourne University.
City Rail Link board chairman Sir Brian Roche says Sweeney brought a wealth of relevant, current experience and a strong academic background. That puts the CRL project in a great position, Roche says.
Just as he's warming up his seat in the AMP Tower, on Lower Albert St, Sweeney is checking previous assumptions on the costing analysis for the twin-tunnel, 3.4km Britomart-Mt Eden job.
Sweeney has decades of working in the management consulting industry, leading big capital programmes, with expertise in value engineering, cost management, procurement and design management. He gives a strong indication that CRL might cost more than projected, but he doesn't know yet.
"The $3.4b was an estimate made in 2014. Things have changed," he says.
"The construction sector has resourcing issues, particularly after the Canterbury earthquakes. The currency is weaker than it was, even a year ago. That means tunnel boring machines and other materials and equipment could be more expensive. I don't want to speculate about cost, but some of the baseline assumptions have changed. I'm working my way through that. I didn't put the budget together. It was very thoroughly priced for the information available at the time. One of the first things I'm doing is re-looking at the baseline assumptions."
Timing is another issue: CRL is already running behind its timetable. Its own website says its request for tender process for the "C3" stage of the job - the tunnels and stations - was "expected to be released March 18". That hasn't happened, and now it's late August.
Sweeney attributes the delay partly to Fletcher Construction withdrawing after its Building + Interiors division lost nearly $1b on big projects.
Now, there are two remaining tenderers for the tunnelling work: the Spanish-headquartered CPB Contractors Pty Ltd; and a joint venture comprising Vinci, Downer, and Soletanche Bachy.
"The [request for tender] for C3 will be released at the beginning of September and it's late because there was a procurement process which basically stalled. The board is considering going down the alliance line with C3," says Sweeney, who backs that approach.
Proposals from bidders will be evaluated by January or February and the successful tenderer will be announced around March or April next year, with work beginning around that time too - "ideally."
The project is due for completion by 2024.
Asked about the size of the tunnels, Sweeney says: "They might build a much bigger tunnel for other reasons - because it gives them a lot more working room compared to a smaller narrower tunnel." But two-level trains are not planned: "For example, in Sydney these take double the time to load and unload."
He expresses relief at working in New Zealand's construction sector, compared to Melbourne. "Industrial relations here are a lot better. When I was head of Grocon, that involved leading construction crews through picket lines. Every window in one of my manager's house was kicked out. Guys followed him wearing balaclavas, and shots were fired over houses.
"I was pleased to leave that industrial relations environment, with guys having security patrols around their houses, people handing me cellphones with voice messages saying 'we will fix you up'.
"In Australian construction environments, it's very hard to have a relationship with your employee because they view the union as their protector. The union controls labour and they're not interested in modernising, using, for example, robots. The construction industry in Australia is held back because the union works aggressively against any improvement. That means they're working against their own members. You have a high-labour, low-technology industry."
But that's behind him and he is now concentrated on getting CRL built, engaged in a new phase of his career and on a project he expects will "transform the city".
• Job: Chief executive, City Rail Link
• Age: 59
• Raised: Porirua, Wellington
• Lives: Remuera townhouse. Still has family home in Camberwell, Melbourne, bach site near Wanaka
• Family: Wife Jacqueline Moloney. Children Grace, 29; Fintan, 27; Eleanor, 24; grand-daughter Maeve.
• Education: Wellington Polytech NZCE civil engineering; Auckland University bachelor of civil engineering and honours; Melbourne University PhD in construction economics
• Past roles include: Executive director, Major Projects Victoria; head of construction, Grocon; managing director, Atelier Projects; chief executive, Ontoit advisory and project management.