CPB Contractors – Australia’s biggest construction companies

CPB Contractors

australia, CPB,


CPB Contractors is a leading Australian construction company, specialising in major infrastructure projects across transport, tunnelling, water, energy, resources, and building.

About CPB Contractors

CPB Contractors is one of Australia’s largest infrastructure contractors and has been established for over 90 years.

Working closely with clients and partners, CPB Contractors is involved in major projects across all construction industry sectors. This includes rail, roads, tunnelling, water, renewables, buildings, defence and resource infrastructure. This top-tier company also operates in New Zealand, Asia, India, and Papua New Guinea.

CPB Contractors is a subsidiary of CIMIC Group, which is an engineering-led construction, mining, services, and infrastructure development leader. 

CPB Contractors have installed over 10,000km of light and heavy rail tracks and approximately 360 tunnels. Also, 11,000km of new and refurbished roads have been built to connect Australian cities. As of today, over 12,000 people work across CPB infrastructure projects and offices in Australia.

The company has significantly contributed to shaping Australia’s infrastructure landscape, providing economic and social value across the country.

History of CPB Contractors

The construction company evolved from its early roots in 1927 and helped shape Australia and New Zealand’s infrastructure across transport, resources, and buildings.

CPB Contractors was only launched in January 2016 following a merger of the CIMIC Group construction businesses of Leighton Contractors and Thiess Construction. Over the years, CPB Contractors has built a reputation for delivering complex and large-scale projects, reflecting its growth from a local contractor to a major player in the national infrastructure industry.

CPB Infrastructure Sectors

CPB is renowned for its expertise in large-scale projects and has excelled in delivering a wide array of infrastructure solutions. Their proficiency spans across sectors such as transport, tunnelling, new energy, building, water, resources, health, and defence. 


CPB Contractors excel in constructing and developing major transport systems, including roads, highways, bridges, rail networks, and airports.

The company has delivered new rail lines, networks, upgrades, station infrastructure, rail systems and overhead line equipment for rail infrastructure projects. For roads, CPB continues to apply market-leading expertise in civil works, bridge structures, building and tunnelling to complete road solutions across Australia and New Zealand.

Their expertise covers both urban and interurban settings and involves complex engineering challenges.


CPB Contractors has applied diverse tunnelling, underground excavation, and other civil works to multiple projects as the premier tunnelling contractor in Australia and New Zealand. 

They have worked on projects worth billions over the past few years, including Sydney Metro, Metro Tunnel, and the Rozelle Interchange of the WestConnex project in New South Wales. 


With the transition to clean energy evolving, CPB Contractors focuses on designing and constructing wind farms, solar farms, transmission lines, and other types of power infrastructure. All renewable projects CPB Contractors is part of are in regional and remote locations in Australia and New Zealand.


CPB Contractors excel in building construction, with a portfolio that includes commercial, educational, healthcare, and residential projects. Renowned for innovation and sustainability, they consistently deliver high-quality buildings that exceed client expectations.


CPB Contractors has an extensive track record of constructing various dams and water storage facilities. They also develop and upgrade water and wastewater treatment infrastructure such as pump stations and pipelines.

Some water projects include TasWaters Capital Works in Tasmania, Paradise Dam in Queensland, and the Water Treatment Plant Upgrade in Victoria.

Healthcare, Resources and defence

CPB Contractors also specialise in other sectors such as healthcare, resources and defence. They work closely with clients to deliver medical facilities and construct large-scale mining and resource projects. Their defence capability includes developing and upgrading critical defence infrastructure across the Navy, Army, and Airforce to help align with national security needs.

CPB Contractors Sustainability

CPB Contractors is deeply committed to sustainability, integrating environmentally responsible practices into their operations. There are five focus areas that CPB is working towards to achieve sustainability outcomes:

  1. Reducing carbon emissions to minimise climate impact of CPB’s operations 
  2. Implementing sustainable design to reduce environmental impacts
  3. Implementing sustainable construction to minimise impact and enhance the natural environment 
  4. Community legacy  
  5. Workforce legacy and safety  

The infrastructure company has also implemented sustainability targets. CPB aims to have net zero emissions for fuels and electricity consumers by 2038. Moreover, 90% of project waste will be diverted from landfills, and 10% of project water will be reused or recycled. 

The company actively pursues energy-efficient solutions, waste reduction, and water conservation in its projects. They also prioritise using sustainable materials and technologies, aiming to minimise environmental impact while enhancing the durability and longevity of their constructions.

Click here to read more about their sustainability targets.

Infrastructure projects CPB Contractors is currently delivering  

Sydney Metro – Western Sydney Airport – New South Wales

As part of the JV with UGL, CPB Contractors has been awarded a $1.8 billion contract to deliver the Sydney Metro – Western Sydney Airport Station Boxes and Tunnelling Works (WSA-SBT).

The project is Australia’s largest public transport project and will see the metro expand into the CBD and Bankstown.

The Station Boxes and Tunnelling contract includes:

  • 9.8 kilometres of twin rail tunnels in two sections. The 4.3-kilometre northern tunnels run from St Marys to Orchard Hills, and the 5.5-kilometre southern section of tunnels runs between the Airport Business Park and the Aerotropolis Station;
  • Excavation and civil works for new stations at St Marys, Orchard Hills, Western Sydney International (Nancy-Bird Walton) Airport, and Aerotropolis;
  • Four hard rock Tunnel Boring Machines (TBM);
  • Building one of the two temporary precast concrete factories for the project on the Western Sydney International site;
  • More than 67,000 concrete segments to line the twin tunnels;
  • Two TBM launch sites at Orchard Hills and Western Sydney International and two TBM retrieval sites at St Marys and Aerotropolis Station.

Construction works are expected to be completed in 2024.

CPB Contractors and Ghella awarded a $1.8 billion Sydney Metro – Western Sydney Airport contract

Source: © Sydney Metro 2024

HumeLink is a new transmission project that will significantly increase the capacity of the electrical network across Australia’s eastern regions. It is one of NSW’s largest energy infrastructures, with approximately 385km of proposed new transmission lines.

Source: © Infrastructure Partnerships Australia 2024

The CPB Contractors and UGL joint venture will oversee the engineering, procurement, construction, and commissioning of HumeLink’s western section. This includes building 148km of 500kV transmission lines, two new 500kV substations, and augmenting Transgrid’s existing 330kV substation in Wagga Wagga.

Metro Tunnel – Melbourne, Victoria

CPB Contractors is the principal contractor for Victoria’s $11 billion Metro Tunnel Project.

The completion of this project is expected in 2025, with CPB Contractors responsible for delivering:

  • all site construction services, including civil works
  • leading the design, supply, installation, testing, integration and commissioning activities for train and power control systems, operational control systems, and conventional and high-capacity signalling on the new Sunbury to Cranbourne/Pakenham line.

Project Spotlight: Melbourne’s Metro Tunnel

Augusta Highway Duplication – South Australia

The South Australian Government selected CPB Contractors to deliver the Port Wakefield to the Lochiel section of the August Highway Duplication project. It is currently being delivered under an alliance with the Department for Infrastructure and Transport, Aurecon, Australasia and GHD.

Construction works include duplicating the existing Augusta Highway into a four-lane carriageway. Also, it includes intersection/junction improvements between the intersection of the Port Wakefield Highway, Copper Coast Highway and Augusta Highway.

Major works commenced in 2022 and all sections will be open to traffic in late 2024.

Augusta Highway duplication is now officially open

As part of Perth’s $5.9 billion METRONET project, CPB was selected to deliver the $200m Yanchep Rail Extension and the Thornlie to Cockburn Link. It involves the construction of three new stations and connects the Joondalup line north from Butler to Yanchep to support Perth’s southern suburbs. Works for this stage of METRONET commenced in 2019 and will soon be completed in 2024. 

Other projects CPB Contractors are currently involved in include:

  • North East Link – Melbourne, Victoria
  • M12 Motorway – Sydney, New South Wales
  • Main South Road and Victor Harbor Road Duplications – South Australia
  • Western Harbour Tunnel Southern Tunnelling works – New South Wales
  • M6 Motorway Stage 1 – New South Wales
  • West Gate Tunnel – Melbourne, Victoria
  • Sunbury Line Upgrade – Victoria
  • Cross River Rail (Rail, Integration and Systems package) – Brisbane, Queensland

Infrastructure projects CPB Contractors have delivered

M80 Upgrade – Melbourne, Victoria

Between 2020 and 2022, CPB Contractors contributed to the Northern upgrade of Melbourne’s M80 Ring Road. The upgrade was located on the M80 Ring Road between Sydney Road and Edgars Road, approximately 14km north of Melbourne’s CBD.

Major works involved widening and realigning ramps, constructing additional lanes, structural works, noise walls, traffic barriers, landscaping, and installing a smart freeway management system. 

WestConnex Rozelle Interchange – Sydney, New South Wales

The $3.9 billion WestConnex M4-M5 Link Rozelle Interchange was designed and built by a JV with John Holland and CPB Contractors. It is a major underground motorway that connects the M4-M5 Tunnels with the Anzac Bridge and Victoria Road in Sydney. 

After four years of construction, the Rozelle Interchange officially opened to traffic in November 2023. Its completion will improve traffic flow, reduce travel times, and enhance access for motorists and public transport across New South Wales.

After four years of construction, Sydney’s Rozelle Interchange is officially open

Transmission Gully Motorway – New Zealand

The $1.25 billion Transmission Gully motorway is the first roading project to be delivered as a Public Private Partnership (PPP) by Wellington Gateway Partnership in partnership with the New Zealand Government.

The 27km four-lane motorway includes 29 bridges and was open to the public in March 2022. Construction works for the project were very complex as it involved steep terrain requiring large-scale earthworks.

Minor construction works and upgrades for the Transmission Gully are still ongoing.

Other projects CPB Contractors were involved in include:

  • Mackay Northern Access Upgrade – Queensland
  • WestConnex M4 Widening – New South Wales
  • Mackay Ring Road – Queensland
  • Torrens Road to River Torrens – South Australia
  • SH1 Southern Corridor Improvements Project – New Zealand

Does CPB Contractors offer a graduate program?

CPB Contractors offers a two-year graduate program designed to provide an immersive and comprehensive experience in the construction and engineering sector. Throughout the program, graduates rotate through different roles and projects, enabling them to develop a broad skill set and deep industry understanding. This structured approach and ongoing support and mentoring equip graduates with the necessary tools and knowledge to kickstart a successful career.

CPB Contractors also offers a variety of undergraduate opportunities ranging from traineeships and vacation programs to part-time employment.

CPB Women in Construction Program

CPB Contractors has partnered with the National Association of Women in Construction (NAWIC). This program focuses on empowering female employees and provides opportunities for networking project tours, development workshops, webinars, awards, and scholarships.

CPB Contractors Women in Construction

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