Groupama III. Central hull assembled
According to the build schedule of the 103 ft long (31.50 m) maxi-trimaran which got underway in the Multiplast yard in December 2004, the central hull has just been assembled. A high precision operation.
The two parts of the carbon Nomex sandwich half hulls were made separately. Cured in an oven to 100°C several times, they have undergone dilations and been subjected to mechanical loads which go hand in hand with the differences in temperature.
In order to ensure that the desired post-curing volume required by the designers (Van Peteghem / Lauriot-Prévost)
is complied with and that the assembly is undertaken to within the nearest millimetre, each half-hull undergoes a laser beam geometric inspection.
Once the two half-hulls are perfectly in line, the assembly being done horizontally, the join is made on the inside and the outside using 7 ¾ inch wide (200 mm) bi-axial carbon fibre cloth.
When the central hull's join is sound, the yard's prototype workers add the bulkheads and flooring to make the whole rigid. Only then will the central hull be turned the right way round and blocked vertically on its cradles as the crossbeams are prepared. Construction of the beams is currently underway and the front one will be added at the start of October. In the meantime, the central hull will be handed over to the finishing team in charge of getting it ready for the paint stage.