Decmil’s West Angelas Sustaining Project roads: design and drainage notes for engineers
Reviewed by Joe Ashwell
First reported on International Mining – News
30 Second Briefing
Macmahon Holdings’ subsidiary Decmil has secured a A$120 million Western Hill contract from Rio Tinto for the West Angelas Sustaining Project (WASP) in the Pilbara, Western Australia. The scope covers a new heavy haulage road, light vehicle access roads and associated drainage, forming key surface infrastructure for ongoing iron ore operations. Geotechnical and civil design will need to address Pilbara haul truck axle loads, segregation of LV/HV traffic, and high-intensity cyclone rainfall in road formation, culvert sizing and erosion control.
Technical Brief
- Western Hill contract value is A$120 million, forming a substantial civil works package within WASP.
- Scope is bundled under Macmahon Holdings via wholly-owned civil subsidiary Decmil, simplifying interface management.
- Package is tied specifically to the West Angelas Sustaining Project, supporting long-term iron ore output rather than greenfield expansion.
- Rio Tinto retains client role and project integration, with Decmil focused on delivery of surface transport infrastructure.
Our Take
Decmil’s work at the West Angelas Sustaining Project in the Pilbara sits alongside its A$81 million MEM workshop expansion at Rio Tinto’s Brockman 4 mine, signalling that Rio Tinto is concentrating a pipeline of brownfield infrastructure packages with the same contractor in Western Australia.
In our database of 466 Infrastructure stories, the Pilbara region of Australia consistently appears as one of the most active hubs for sustaining capital projects, which suggests that assets like Western Hill are being managed for long-term throughput rather than short mine-life extensions.
The repeated pairing of Macmahon Holdings Limited and Decmil on Rio Tinto Pilbara work indicates a stable contractor ecosystem around these iron ore operations, which typically reduces interface risk for complex sustaining projects such as WASP.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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