Mount St Cable Stay Bridge Project

Project Overview

Completed in 1972, this concrete bridge is cable-stayed with a semi-fan system. Located in Perth’s CBD, it functions as a bicycle and pedestrian crossing.

The project works included the installation of a new pre-cast concrete mast, new cable stays, along with LED feature lighting on the mast and deck.

Fast Facts

  • CLIENTMain Roads WA

Scope of Works

  • Installation of temporary mast and cable stays
  • Transfer of loads from old cable stays to temporary stays and mast
  • Removal of old mast and stays
  • Installation of new precast mast in 3 sections with post tensioning bars connecting the sections and installation of new cable stays
  • Transfer of loads from temporary mast and stays to permanent mast and stays
  • Removal of all temporary works
  • Application of protective and anti-graffiti paint
  • Reinforcement of the balustrade
  • Installation of LED feature lighting


  • First use of MK4 multi strand cable stay system in Australia
  • Works completed safely while working over a live freeway with no full road closures required
  • We changed the temporary cable stay attachment from an external steel cradle to a central connection through the bridge with the advantage of completing all stressing works during the day with no lane closures and saving on public disruption and programme time