Foldable Torpedo Anchor: A Novel Anchoring System for Deepwater Floaters

Ultra-deepwater energy resources are explored very little to till date. Depletion of oil and gas in shallow water depth made the exploration into the deep and ultra-deepwater resources. The offshore floating energy extractors like wind turbines, oscillating water column, offshore oil exploration production and drilling platforms often needs an efficient anchoring system. The development in offshore gas exploration and platform construction has made use of several anchor types like vertically loaded drag anchor (VLA), Omni-Max anchor, suction embedded plate anchor (SEPLA) and dynamically embedded plate anchor (DEPLA) to withstand heavy mooring loads. In the late 1990s, torpedo anchors were made, which were inexpensive and less time-consuming to install due to the simple installation technique. The anchors penetrate the target embedment depth by the kinetic energy acquired in the process of free fall, and the installed anchor is moored to the floating structure. Even though the torpedo anchors are able to withstand ample horizontal loads, in the case of vertical load-carrying ability, their performance is poor. This is one of the main reasons the concept has not become very popular in practice despite its simplicity. Hence, there is a need to improve the conventional anchor suffering from low vertical load-carrying ability. The objective of the present study is to depict the novel foldable torpedo anchor (FOTOAN) concept, design developments and installation mechanism. The FOTOAN is similar to the conventional torpedo anchors but comprises of foldable wings and fins which extend laterally to increase the pull-out resistance. Thus, the FOTOAN can be an efficient technique for deepwater anchoring applications.