Delta Group were engaged by the WA Government Department of Transport to complete asbestos removal, demolition, services upgrade and civil works at Two Rocks Marina in north Perth.

Our scope of works included:

  • Asbestos Removal roof sheeting and redundant services
  • Services decommissioning and demolition of 2 buildings
  • Installation of 800m-180mm diameter fire services
  • Installation of 600m -125mm diameter potable water
  • Installation of 250m -160mm diameter salt water bore line
  • Installation of 450m of services through trenchless technology
  • Installation of power and communications services, including 4 x 10m high light poles
  • Installation of 160m x 300mm storm water drainage, including pits and treatment device
  • Earth works and asphalting of 5000m2, with 300mm layer thick hardstand for boats

Key challenges faced involved installing services due to a high groundwater table; being within close proximity to the ocean, the groundwater table fluctuates with tidal movements and dewatering is impossible. Unknown services were also encountered during trenching works, as well as hard rock during drilling and trenching which was not reflected in geotechnical reports. Similarly, the interface with boat lifting movements across the site presented challenges for people and plant.

Key outputs included:

  • New method of trenching under water proved successful and all pits and firewater services are installed with new proposed methodology
  • Use of tougher drill rig head attachment for drilling in rock worked well and finished the service installation by drilling well before time
  • Outsourcing road base supply from other suppliers enable asphalting subcontractors to complete their scope of work as per planned program
  • Overall, the project was completed on time despite all the challenges faced