With the growth of oil and gas industry into deep water, the offshore infrastructures have developed to resist deep water conditions up to 3000m. The nature of deep-water environment requires foundations of these systems to sustain a high vertical load while maintaining a reasonable installation cost. However, as the loads sustained by the foundations increase with increasing water depth, the installation becomes more complex and costly. Due to the cost of foundations being a significant percentage of the total cost for an offshore structure, a more reliable and economical foundation type can bring in considerable benefits, especially for deep water applications.
Dr. Robert Gilbert, a professor at The University of Texas at Austin, and his students have developed Flying Wing Anchor® (FWA®) as a sustainable anchor concept for deep-water offshore wind turbines. This new concept combines the advantages of low-cost installation of torpedo piles and high efficiency of vertically loaded plate anchors. Anchor is installed mainly in two main steps: initial penetration through free-fall like a torpedo anchor, followed by drag embedment installation like a plate anchor. FWA® is designed to be installed by gravity first with the closed shank which is held on the anchor fluke by the coupling mechanism.
FWA® contains two plates connected by two beams as shown below. The back plate consists of four triangular fins attached on the beams with two oval fins on either side. A fluke-shank coupling mechanism is designed to keep the shank closed and attached to the fluke until the anchor reached the designed pitch angle. FWA® initially dives deeper like torpedo piles and follows drag-embedment installation like plate anchors by using environmental loads, achieving an efficient installation method.