Works on the portside infrastructure were already under way in Wellington, and would begin in Picton with demolitions in about a week. Photo: RNZ / Mark Papalii
More details about the new generation of Interislander ferries have come to light in briefings to MPs - including that the final cost is not yet known.
The ferries will also be diesel-hybrids with a capability to use alternative fuels, and able to travel faster through the Marlborough Sounds than the current ships without causing large disruptive waves.
Ferry Holdings - the company set up by the government to manage the procurement and operation of the new ferries - appeared before the Transport select committee on Tuesday, with board chair Chris Mackenzie giving a run-down on some of the benefits.
They would be propeller-driven diesel-electric hybrids with batteries that enable a safe return to port and which could be operated in the port - allowing the diesel motor to be turned off when the ships were in port.
They would more manoeuvrable both in the harbour and at sea than the current ships, and could travel at 20 knots - including through the sounds.
"The new form of the hull enables it to go through there, and the wave energy is such that it's not going to be restricted in the way that the current ferries are ... they are very much advanced on where the existing ferries are."
They would also save on some operating costs because their design allowed some areas to be closed for off-peak sailings, which would save on crew and maintenance costs.
The first ship would be delivered in early 2029, partly to iron out any issues ahead of the second ship's arrival before Christmas the same year. An earlier delivery would not have been possible because of the need to upgrade the ports to service the ships.
Works on the portside infrastructure were already under way in Wellington, and would begin in Picton with demolitions in about a week.
Final cost not yet known
The ferries are the government's answer to iReX, the ferry replacement programme started under the previous Labour-led coalition with New Zealand First, which was cancelled by Finance Minister Nicola Willis as one of the first orders of business when the three-way coalition came to power, citing cost blowouts.
Willis' predecessor - just weeks out from the election - had been rejecting requests for funding for the project to increase, but ultimately provided contingency funding to keep the project going until a new government was in place to make decisions.
NZ First leader Winston Peters was later appointed Minister for Rail and given responsibility for handling the replacement project, which he promised would cost less than iReX - a benchmark he claimed to have achieved when announcing the new ships would be built by Guangzhou shipyard in China.
The total project was estimated to cost $1.86 billion, and unable to surpass $2b.
Whether that is lower than what the final sum for iRex - including the break fee and the costs of cancelling the previous project - remains unclear because the estimated final cost of iReX remains disputed.
Peters and Willis have claimed it could have blown out to $4b, but that this was based on average percentage cost increases for other infrastructure projects around the world. The previous government had rejected a request for $2.6b additional funding, providing only $750m.
At any rate, Ferry Holdings acting infrastructure manager Richard Hickman confirmed to Green MP Julie Anne Genter the design was still at a relatively early stage, and the final cost would not be known until the final bill arrived.
However, he said the company was "comfortable" they had enough contingency to get it across the line - both on time and within the cost constraints.
The cost of the vessels was not the primary driver for them, indicating it was more about getting the right ships at the right time, Mackenzie said.
He also noted that while the linkspans connecting the rail-enabled ships to the mainland - and allowing trains to be driven onto the ships - would remain in Crown ownership, the ownership of the rest of the infrastructure was still being negotiated between Ferry Holdings, KiwiRail, and the two ports.
They were very appreciative of how cooperative KiwiRail and the ports had been, he said.
"It is difficult dealing with some because they have, if you like, got ferry-itis because there were some ferry changes that were identified pre-iReX, then they went through iReX, and now they're going through this programme."
The company was determined to deliver on time and under budget if they could, "subject to normal New Zealand infrastructure issues", Mackenzie said.
The ships being designed also have engines with the capacity to in future use alternative fuels "but there's no indication yet that anyone is producing it in quantities sufficient for the ferries to actually use".
Additional geotechnical surveying had been needed to assess the locations for the port infrastructure, which was in a different location than under iReX for both ports, Hickman said.
"There will almost certainly be some more but what we've got has been very useful. If I was to summarise, Wellington it's been a good story, Picton not such a good story - we've got rock a little bit higher than we would like.
"But we're dealing with that, and that's been factored in with our risk thinking and ... analysis for affordability."
The government contribution was capped at $1.7b and the full package included a $415m contingency.
A spokesperson for Peters said the remaining variable was the landside infrastructure costs, but both ports were confident if coming within expected costs projections by the mid 2026 deadline.
Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.
