Mt Isa Access Bridge
Concept Design
A lightweight, resilient long-span access solution enabling safe worker crossings in a remote, flood-prone environment.
CSS developed the concept design for an 82-metre pedestrian access bridge required to provide safe, daily worker access across a flood-prone watercourse at a remote mining site.
The project demanded a structurally efficient, low-maintenance solution that could perform under challenging environmental conditions while accommodating restricted single-person use. CSS delivered a robust concept design based on clearly defined performance criteria—including flood immunity, constructability, and lightweight structural efficiency—ensuring the bridge can be reliably operated, safely maintained, and seamlessly progressed into detailed design.
Technical Achievements
CSS designed a long-span suspended cable bridge system featuring steel support towers, a lightweight FRP deck, and shallow concrete anchor foundations optimised for remote construction. The concept incorporated tailored load modelling, a defined flood freeboard strategy, dynamic performance considerations, and mine-specific access assumptions. Early identification of critical design factors such as debris loading, soil–structure interaction, and geotechnical dependencies provided clarity for detailed design and future verification stages.
Benefits to the Client
The selected bridge design form delivers a safe, reliable crossing with minimal material use, reduced construction complexity, and lower lifecycle maintenance—all essential in a remote mining environment. By aligning structural design with actual operational requirements, CSS produced a cost-effective solution that avoids over-engineering while maximising safety and performance. The clear documentation of assumptions, risks and departures enables transparent decision-making, reduces uncertainty for future stages, and ensures a streamlined transition into detailed design.
