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With the deployment of the TetraSpar demonstrator, a significant cost-reduction is realized in the field of offshore floating wind turbines. The TetraSpar floating wind turbine foundation brings a milestone that emphasizes on a modular and fully industrialized foundation that consists of main components already widely available in the current wind energy supply chain. In an effort to provide an open approach to the development of the concept, this paper aims at giving a description of the design in order to enable an educated discussion of different design philosophies and their influence on material usage and production times. The description of the different subcomponents of the system should allow any entity to build a model for comparison and/or benchmarking any of their own findings against this concept. It is the authors’ expectation that this open approach to technological discussion is paramount to obtaining continued cost-reduction in the area of floating offshore wind—for this concept and others.

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Electromagnetic induction methods are effective in locating unexploded ordnance (UXO). However, the induction EM instruments that are used for UXO detection generally have limited bandwidths and provide little, if any, information for UXO classification. It is well known that the broadband induction EM response from confined conductors (such as UXO) can be parameterized in the time-domain as a series of damped exponential decay curves, and in the frequency domain as a set of discrete real first order poles and their residues. Characteristic decay time or its equivalent real pole has been shown to be a function of characteristic target dimensions, target conductivity, and relative magnetic permeability. Therefore, parameterization of the broadband EM response in terms of these characteristic modes provides a basis for the classification of UXO anomalies.In this paper we have used a numerical method (Prony) to analyze TEM decay curves to obtain a set of exponential decay time-constants and their corresponding residues. Using a commercially available field data acquisition system, we have acquired fast transient TEM data from UXO. We show that these data can be analyzed and displayed in a way that is simple to understand and useful for classifying the TEM response.

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