Progress on Auckland's City Rail Link has been shown via new video footage released.
Filmed this morning, it shows the construction site on lower Queen Street and beneath Britomart.
It comes as the City Rail Link company (CRL) signed a contract with the developer Link Alliance to build the three main stations and complete the construction of the tunnels.
The contract is for the single biggest programme of work for the project.
The New Zealand and international companies in the Link Alliance are Vinci Construction Grands Projects, Downer NZ, Soletanche Bachy International NZ, WSP Opus NZ, AECOM New Zealand and Tonkin + Taylor.
Transport Minister Phil Twyford said the signing of the contract was significant for Auckland and New Zealand.
"Given the competition worldwide to build infrastructure, the whole country can take pride in the fact that such a high calibre of international companies want to come here and help build a better future for New Zealand."
The City Rail Link is the largest transport infrastructure project undertaken in New Zealand.
When completed in 2024, twin 3.45km tunnels beneath central Auckland will convert the current dead-end station at Britomart into a through station connected to Mt Eden, doubling the capacity of the city's rail network.