End of the line for CRL’s astonishing ‘can do’ contract at Britomart
21 October 2021
Work on one of the most complex engineering challenges undertaken in New Zealand ended today with completion of City Rail Link’s (CRL) C1 contract at Britomart Station.
“Over 5-years of exceptional and inventive work pushing construction techniques to new limits delivered an outstanding result – preserving Auckland’s historic past while building a world-class railway for a modern city,” says City Rail Link Ltd Chief Executive, Dr Sean Sweeney. “There is a lot our C1 workers, and wider New Zealand, to be proud of.”
C1 was one of the earliest contracts for New Zealand’s largest transport infrastructure project to revitalize the city’s rail network.
Critical to CRL’s success was turning the dead-end Britomart Station in Auckland’s downtown into a two-way through the station with twin rail tunnels built in the basement of the city’s imposing and historic Chief Post Office (CPO) .
Work began in 2016 when the CPO, the main entrance to the Britomart Station, was closed. CRL Ltd and its contractors, Downer NZ and Soletanche Bachy JV, built the tunnels in the 109-year-old heritage-listed building, across the lower end of Queen Street and below the Commercial Bay office and retail development to connect with CRL tunnels in Albert Street.
“Achieving all that required some astonishing engineering – we pushed accepted construction boundaries with some amazing innovative techniques,” Dr Sweeney says.
- Fourteen thousand tonnes of a building with a top heritage rating were safely transferredon to temporary foundations
- machinery was modified specifically for use in confined conditions under the CPO
- special grade steel manufactured in New Zealand for the first time teams was used in the contract
- Workers had to contend with muddy reclaimed land with the old building perched on temporary foundations just a few centimetres above them
- Britomart Station remained fully operational with a connecting door separating busy platforms from a construction site.
- Delivery was challenged by multiple covid level-4 shutdowns in Auckland
“Great collaboration produced a great ‘can do’ attitude,” Dr Sweeney says.
Years of planning, design and partnerships involving CRL Ltd and its contractors with Heritage NZ,Auckland Council, Auckland Transport, the Commercial Bay developers and other neighbours, andTāmaki Makaurau Iwi were the foundations for a positive outcome.
Around 10,000 Aucklanders were given a ‘sneak peek’ behind the project’s hoardings when they walked a section of Britomart tunnels in November 2019.
The project handed back to Auckland a fully restored CPO last April. The building has resumed its role as the “front door” for the Britomart Station.
Traffic-congested Lower Queen Street in front of the CPO has been replaced by a striking people-friendly square known as Te Komititanga, Meaning to mix or to merge. The layout of TeKomititanga’s basalt pavers was designed by Mana Whenua artists and weavers.
DR Sweeney says C1 ticked many other boxes: sustainability, preserving fragments of Auckland’spast uncovered during construction, cultural and social impacts including job creation opportunities and an improved environment.
“C1 set very high standards and new benchmarks for other CRL contracts, and for the wider infrastructure industry,” he says.
The $4.4bn CRL project connects Britomart and the Mt Eden Station on the Western Line with tunnels 3.45 kilometres long under central Auckland. Two new underground stations will improve access in and out of central Auckland – New Zealand’s largest employment hub.
CRL is planned to finish in late 2024 and will double the number of people living within 30 minutes of travel of the central city with train services that will be more frequent and faster.
View the media release here
About Britomart Works and CRL
Work began in 2016 when the CPO, the main entrance to the Britomart Station, was closed. CRL Ltd and its contractors, Downer New Zealand and Soletanche Bachy built the tunnels in the 109-year-old heritage-listed building.
- The CRL will use twin 3.4 kilometre long tunnels up to 42 metres below the city streets. It is estimated to take five and a half years to build at a cost of $2.5 billion when inflated to 2024 costs
- Two new underground stations at Aotea (11 metres deep) and Karangahape Rd (33 metres) and a re-developed Mount Eden Station
- Cut and cover construction along Albert Street and at Eden Terrace
- Most of the twin 3.4 kilometre long tunnels will be built with a tunnel boring machine
- 7.5 metre diameter tunnel boring machine (about half the size of the one used at Waterview)
- About one million cubic metres of spoil – more than Waterview because of station excavations
- 88 subterranean properties affected by tunnels
Benefits to the Auckland economy
- A successful Auckland is pivotal to New Zealand’s future economic development, with GDP per capita 30-50% higher than other parts of the country. Auckland provides about a third of New Zealand’s GDP
- Improved accessibility, particularly to the city centre is the key to Auckland’s economic growth. By 2041, the city centre will account for 30% of the region’s GDP
- Transport is critical to shape urban form and lead economic development. Cities with efficient transport systems are more productive than dispersed places. Significant economic gains can be made from transport investment that improves access for people into areas of high employment density
- Cities form and people choose to work in them because they are more productive due to scale and proximity. The availability of a skilled and educated workforce attracts high value-added businesses
- There are a number of economic benefits from businesses and a skilled workforce being close together in city centres. These agglomeration benefits drive higher productivity and wages, making successful city centres increasingly important to a country’s economy
- Auckland is New Zealand’s commercial capital; home to more than 60% of the top 200 companies. Auckland accounts for over 34% of NZ jobs, most in the urban areas, while Wellington, Hamilton and Tauranga combined, account for 13% of jobs
- The city centre is the hub of Auckland’s economy with 1 in 6 employees working there and up to 16,000 employees per square km. City centre workers earn 27% more than the average for Auckland
- Major construction projects, such as the CRL, usually create increased economic benefits by employing people and spending with local businesses
Source: City Rail Link Media Release 2017