1983 - Leighton acquires Thiess Pty Ltd

Hochtief buys out Westfield and acquires Thiess Contractors Pty Ltd through Leighton Holdings Ltd, of which Hochtief is the major shareholder.

1983 - Hayman Island resort development

Thiess Contractors develops a long-term building strategy and constructs a series of resorts. The company is recognised by the industry as a serious builder.

1984 - First waste management contract

Thiess Contractors successfully secures a seven-year contract with the Brisbane City Council for receiving, spreading, compacting and filling eight landfill refuse disposal areas. It is one of Thiess’ first jobs in environmental services.

1984 - First remediation contract

The clean-up of the Northern Territory’s Rum Jungle Uranium Mine becomes Thiess’ first remediation project.

1984 - RAAF Base Tindal

Thiess successfully completes the initial Stage 1 development of the RAAF Base Tindal, located in the Northern Territory and home to the 75th Squadron. Ten years later, Thiess is awarded a contract to construct more than 3km of new aircraft roadways.

1986 - Thiess process engineering

Thiess acquires the Leighton Major Projects Division, commencing its Process Engineering business.

1987 - Correctional facilities

Thiess’ construction of the Barwon Prison in Victoria, to United Nations' minimum standards, signals its expansion into correctional facilities.

1987 - Thiess Environmental Services Pty Ltd

Thiess identifies environmental services as a core business activity and establishes Thiess Environmental Services as a subsidiary.

1988 - World Expo '88

Thiess completes the construction of the iconic tensions membrane structures, as well as many of the pavilions for the World Expo ’88 in Brisbane. Work is also done to reclaim parts of the South Bank Parklands site from the Brisbane River.

1988 - Wollongong Waste Collection contract

This includes the Wollongong Waste Collection contract, one of the largest contracts of its type in Australia. The seven year contract marks Thiess’ involvement in all aspect of waste collection, handling, transfer and disposal.

1988 - PT Thiess Contractors Indonesia

Thiess is established in Indonesia. In a joint venture with PT Mintekindo Utama Into, Thiess wins mining contracts in Kalimantan and spearheads all Leighton Group activities in Indonesia.

1988 - Sydney harbour tunnel

Thiess demonstrates its sophistication as an engineering construction group by delivering Australia’s first immersed tube road tunnel.

1989 - Granny Smith gold mine

Process Engineering completes several mining projects, including the installation of a grinding mill at the Granny Smith Gold Mine.