This is a two phase contract
Wave-tricty Ltd intends to construct a full-scale concrete hybrid generation platform, which will be a large and complex build. Detailed engineering design is anticipated to commence in Q1 2019. The platform hull will be a ship-shaped barge circa 100m x 25m and will be constructed from marine grade concrete.
There are a number of construction methodologies available to build this type of structure, each with varying advantages and disadvantages with respect to the design of the platform hull. The requirement is to conduct construction feasibility study to provide the Wave-tricty Ltd design team with a recommended construction methodology prior to starting detailed engineering. This will minimise design risk and cost during the next phase of works and allow for early engagement with potential fabrication sites for the platform.
In undertaking this study, the following areas shall be investigated and evaluated in terms of technical advantages and disadvantages. An associated high-level qualitative cost analysis shall also be presented, in order to provide final recommendation of a suitable construction strategy:
A summary and background information of each platform hull construction methodology shall be presented to include but not be limited to:
• Reinforced concrete (cast in situ or precast);
• In-situ monolithic casting (slip form);
• In-situ casting using precast elements (slab, honeycomb structure);
• Pre-stressed concrete;
• Post-tension concrete.
Identification of the likely construction facilities that will be required:
• Any specific quayside water-depths to ensure sufficient clearance of the build at various stages of construction and load-out;
• Review use of assembly areas – precast assembly area for modular build and full assembly;
• How precast elements could be used and limiting factors, considering transportation (road, ship etc.) and platform requirements for modular build;
• Review cranage – evaluate maximum capacity of cranes required at various boom reach with an estimate of largest precast frame, module;
Platform hull build methodology:
The following main build concepts shall be investigated and reported: Construction build within a dry-dock:
• Calculation of minimum number of platform hull elements (horizontal position) to determine required buoyancy to float-out the platform hull prior to flooding dock and tow platform hull to quayside to complete build and fit-out;
• Associated costs with occupying dry-dock for duration of build;
• Discuss opportunities of flooding dock, whilst building platform, evaluate consequences of disruption of build, wash down event etc.
• Evaluate slip-forming methodology of constructing the platform in a vertical position in the dry-dock;
• Evaluate methods on over-turning platform hull to its longitudinal position (if feasible);
Floating barge construction:
• Build platform on top of barge(s);
• Capital Expenditure (CAPEX) of purchasing barges