The contract covers 3.2km of 7.18m excavation diameter twin tunnels, along with connections to cut-and-cover tunnels at each end, and three new stations, two of which will be built underground. The tunnels will be excavated by EPBM.
Of the stations, the following details were issued in the RFP: Aotea Station – construction of a 15m-deep, 300m long cut-and-cover station; Karangahape Station – construction of a 32m-deep mined underground station; Mount Eden Station – construction of a new station to provide interchange between the CRL and the existing Western Line including a 7m deep open trench for the CRL platforms.
The full project is due to cost NZD 4.42bn (USD 2.92bn) and to complete in 2024.