"There's trouble down below."
Those are the words of Kiwirail's chief operating officer who says the upgrades to Auckland's rail network are "a big mop up" and require about 26 kilometres of the network's foundation to be rebuilt.
It comes as the Super City is expected to face disruption in the coming years due to much-needed upgrades to the foundation of the network and some of the rails and sleepers.
Official information requested by AM has found that officials knew they needed to replace the foundation several years ago, but planning began four years ago. Funding was allocated two years ago and Government Ministers were advised of the schedule late last year.
Kiwirail Chief Operating Officer David Gordon says about 60 percent of the faults on the city's network are a result of unstable foundations.
"[It's] just like building a house. If it's on wonky foundations nothing actually quite works."
He said the neglected foundations cause reliability issues to the network and if the tracks get out of alignment "we slow the trains down".
"But it does go to the fact that you can't offer a decent service, and if you're going to put $4 billion into City Rail Link and bring the western suburbs 20 minutes closer to the city, you just don't do that on top of an asset that can't perform for the rest."
Gordon told AM with passenger numbers expected to "skyrocket" when City Rail Link opens in the mid-2020s, it would be the "totally wrong decision" to leave the upgrades until the rail link is open.
"The type of maintenance we need to do post-City Rail Link is quite different to the maintenance we do now. Because we won't get so much time on track and we won't have so many people on track," he said.
"We've got to do it now before it's there."
He said Kiwirail didn't have the "ability or the means" to fund the much-needed upgrades until 2018, and now they are facing "a big mop up".
"We've got to rebuild around about 26 kilometres of the existing network from the bottom up. You can't just pick away at something like that, you've got to have a big programme."
Gordon told AM once the upgrades are finished, the network will provide predictability and reliability so users "can plan your life around the train timetable".
"We know we had problems, we've known that the asset was built right back in the 1870s. The issue is how do you actually do this work and how do bring these resources together? Because once we start, we're going to be working 24/7."
He added the upgrades will cause "massive disruption" and "it's the type of job you just do not want to do unless you feel compelled to do so".
Watch the full interview above.
