Engineering company TWD has designed an innovative seafastening system to transport monopiles to an offshore wind farm in a more cost-effective way. The system is suitable for monopiles of all sizes, including those up to the 11m diameter in the foreseeable future without any changes to the support structure.
The innovative seafastening consists of two supports fixed to the deck of the vessel either transversally, across the vessel, or longitudinally, from bow to stern. The design is based on the principle of a hammock. One side of the support is fixed rigidly upright while the opposite side frame is hinged at the base. Between the two sides a special designed rope is slung in a cross-over pattern, designed to avoid lateral movement of the monopile.
When loading the monopile on to the vessel the hinged support frame is held open and as the ropes take the weight of the monopile this support automatically closes. Contact pads on the upper horizontal part of the frame will come to rest on the monopile securing the lateral support. Stacking a second frame on top of bottom support frame is possible. The upper support frame is then equipped with a hydraulically operated lifting arm to raise the rope to one side to give access to the monopile below.
The whole seafastening uses less steel than conventional designs saving on cost and weight. Mobilization and demobilization time between projects will also be faster and easier, giving you more time to relax in your own hammock in the sun.