GUINEA BAUXITE EXPORT TERMINAL

PRDW was appointed by Alufer Mining Ltd to undertake the planning, detail engineering and construction supervision for the marine infrastructure of a new marine transhipment facility in Guinea, West Africa for the export of 5.5Mtpa bauxite.

The marine infrastructure comprises a rubble mound causeway and breakwater providing access and protection to a barge load-out berth. The load-out berth is positioned at the end of the causeway to achieve maximum water depth for the barges and to support the ship loader. The load out berth consists of four piled dolphins and a suspended concrete deck supported on the two central dolphins and on a block foundation on the shore-side.

The barges are loaded with bauxite at the tide restricted load-out berth before being transported to the offshore transhipment site where floating equipment is used to unload the barges and load an ocean-going vessel  (OGV).

The scope of work included:

• Site investigations
• Coastal processes including all required numerical modelling
• Feasibility studies to select the most suitable solution
• Design of a rubble mound causeway and breakwater
• Design of a piled berth structure
• Construction drawings and reinforcement schedules
• Specifications and BOQ’s for tender purposes
• Transhipment and throughput analysis using a discrete event simulation model
• Vessel motion modelling and underkeel clearance
• Navigational layouts and specifications
• Review of tender results and risk analysis
• Assessment of construction methods
• Physical model testing
• Sediment transport study to feed into the EIA process
• Construction supervision and engineering support

Numerical wave, current and sediment transport models were developed to assess the coastal processes around Cap Verga. The MIKE Spectral Waves model was used for wave refraction modelling while the MIKE Flow Flexible Mesh model was used to simulate tidal and wind driven currents as well as water level variations. MIKE MA was used for vessel motion modelling.

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