Customer: Cook Islands Port Authority

Location: Rarotonga, Cook Islands

Contract type:  Construct Only

Construction Period: 1.5 years 


Project Capabilities

Civil Marine

Fast Facts

  • 270 m long wharf
  • 80,000 m3 of dredging
  • 92 m extension of breakwater
  • 50 local workers

The Cook Islands Port Authority engaged McConnell Dowell to deliver the project, which aimed to expand existing port facilities that were ageing and unable to accommodate large scale cargo and cruise ships, limiting economic growth in the Cook Islands.

The scope of works included:

  • construction of a new 270 m long wharf,
  • dredging and widening of the main harbour to increase the turning bay available to ships,
  • armoured revetment shore protection around the entire harbour
  • demolition of other wharf structures and buildings
  • provision of new buildings, lighting and wharf facilities.

The Challenge

The project was located in a relatively remote Pacific Island location, and therefore had to be self-sufficient in terms of all its operational requirements including power, water, and plant maintenance. We established extensive site facilities to service the project, including a dedicated concrete and crushing plant, testing laboratory and workshops.

The port needed to remain fully operational during the construction period. In addition, the oil and gas bunkering manifold located in the middle of the existing wharf needed to be maintained and accessible until the new manifold was constructed.

The Solution

The port remained fully operational during the construction period and to avoid disruption, was built in approximate thirds, with each section fully completed before commencing the next. The new wharf face was constructed from a mixed wall of steel tubes and sheet piles with a concrete capping beam and 40m wide structural pavement behind the wall. The deck was constructed in three parts as a total of 270m long x 30m wide x 500mm thick reinforced concrete slabs plus additional aprons and turning areas to access the new slabs and existing port facilities. A number of initiatives were engaged to expedite the works, including altering piling techniques and the construction methodology for the tremmie concrete. Another innovation was the development of an alternative retaining wall load flow path that allowed for reduced infill sheet pile and welded interlock length, thereby reducing both the cost of these works.

Keys to success

A collaborative approach was taken working with the client and their designer to provide value engineering to the project to ensure that it was within the client’s budget. This project demonstrates our flexibility and multidiscipline capability with team members working across specialties to complete the project and prevent lag times.