Grouted Screw Moorings Whitsunday Islands

Scope of work

Purpose: Provide environmentally friendly Public Moorings at sites around the Whitsundays area.

Description of Works by PMG:

  • Undertake the fabrication of our 4m long Environmental Mooring pins in our Townsville workshop,
  • Preparation of all materials, equipment and crew for transportation to the installation sites selected by QPWS,
  • Undertake installation of 29 x Grouted Screw Moorings at the preselected sites within the Whitsunday Islands.
  • These environmentally friendly moorings were installed into the seabed by commercial divers operating our specially designed Hydraulic Underwater Mooring Machine (HUMM).
  • The diver is supported by a topside crew that pumps grout, via an umbilical, down through the mooring pin as it is screwed into the seabed.
  • The rotation of the pin mixes the grout with the substrate material to form a column of concrete 4m deep with a 0.6m diameter.
  • Once the concrete has cured a selection of the installed mooring pins were load tested using a 6 tonne vertical load, to confirm they have achieved the required holding power.
  • Specialised mooring tackle was then connected to the mooring’s pad eye, at seabed level. This tackle uses a floating line that is suspended vertically using a subsurface buoy to provide catenary action for the vessels using the moorings. This has the effect of minimising shock loading during adverse weather conditions.
  • The moorings were installed for use as Public Moorings at selected high use sites in the local Whitsundays Islands and Bait Reef area of the Great Barrier Reef Marine Park.

Make an Enquiry



30 May - 25 Aug 2017

Whitsunday Islands

Case Study

Make an Enquiry