Bulk Earthworks and Port Breakwater
Client: CITIC Pacific
Contract Value: $128 million
Completion: October 2010
Location: Cape Preston, WA
CITIC Pacific Mining’s Sino Iron project is a world-class, large-scale magnetite iron ore project, the first of its kind in Western Australia. It included the construction of a 4.5km long breakwater, a 1,700 bed accommodation village, a 1,700m2 warehouse and the installation of 12 giant grinding mills. VDM Group was involved in virtually every facet of this project providing innovative alternative solutions that were both cost and time effective.
The construction of the breakwater and land-backed wharf at Cape Preston was the first joint venture between VDM’s construction division and NRW Pty Ltd. VDM was responsible for the construction of the breakwater while NRW took care of the bulk earthwork. VDM set up a quarry operation close to the site and began producing the required amount of material to design specification. This resulted in a total of 10.1 million tonnes of rock, from core to 15 tonne armour, being quarried in just 13 months.
This impressive timescale is largely due to the fact that VDM owns and operates its own quarry equipment including drills, excavators, loaders, dump trucks and HD screens, rock-sizers and crushers.
However, for some projects naturally occurring rock is not the preferred option for the outer layers of marine structures – those that take the full impact of an ever moving ocean. Instead, proprietary concrete armour units are specified as a substitute to protect breakwaters from tidal conditions over the long term. These concrete units are designed to protect the finer material below the armour layer from severe wave action, and dissipate the energy to reduce the wave run-up, overtopping and reflection.
To protect the Cape Preston breakwater VDM unloaded, transported and placed with great precision 10,626 concrete Coreloc blocks weighing up to 30 tonnes using specially modified 45 tonne forklifts and low-loaders and, when necessary, 100 to 600 tonne cranes using GPS guidance systems specially modified by VDM.
The work also included the excavation of adjacent areas to facilitate the future construction of a desalination plant, fuel farm, substation, drainage facilities and associated access roads – and every part of the project had to meet local cyclone regulations.
VDM's Innovation
The VDM Group constantly seeks innovative and sometimes radical solutions to the challenges it faces when undertaking consulting, construction and contracting projects.
The Sino Iron breakwater project at Cape Preston required unique equipment including a super heavy-duty divergator screen, super reach excavators, forklifts, low-loaders and heavy lift cranes all with GPS capability, as well as specialised equipment to handle and install Coreloc concrete armour blocks imported from Thailand.
One of VDM Group’s core competencies is marine structural design and construction.
The Cape Preston breakwater project was completed within the client’s original schedule, despite a 40% increase in work scope during construction, and within the revised budget which took into consideration the increased scope of works.
