## 3 Electrode Station Configuration
### Eighth Electrode Station Configuration--Straight Frames Adapted to a T-Shaped Protective Dam
However, if the frames are close to the surface, it would lead to greater mechanical stress due to the waves, as well as to the presence of a breaking wave, whose water presents much greater resistivity, which would lead to worse results in terms of electric field. Therefore, the next approach is to place the straight frame at such a depth that it is always out of reach of the breaking waves (below 3 m at Stachtoroi and 10 m at Korakia, according to a respective sea wave behaviour assessment study conducted by IPTO) and rises above the surface with an appropriate suspension system. One option is for the straight frames to be placed radially in relation to the central base (as in Figures 17 and 18), and the other, for them to be placed perimetrically to the base, as is analysed in Section 3.11. There can be other configurations, with the placement of frames in a linear arrangement, parallel or vertical to a respective line, in one or more rows, etc., but, in terms of field analysis, they are identical/similar to previous cases (with the only difference being the developing absolute potentials and the remote earth resistance of the electrode station, due to the absence of a dam). Figure 17 shows the cross-section of the arrangement of vertical straight frames of length \(\ell_{f}\) in the sea around a central base of \"gross\" radius \(R_{K1}\) (where gross radius means the radius of the structure, along with the necessary distance \(d_{r1}\) from the structure), which are radially mounted and laterally supported, apart from the base, with an equal number of radius \(R_{O}\) frame guides, constituting the ninth configuration. The upper frame level is at depth \(h_{u}\), which is greater than the depth reached by the breaking wave water, while the seabed is at a depth \(h_{sb}\), greater than the sum of the upper frame level \(h_{u}\) and the frame/electrode rod height \(L_{el}\). Figure 18 presents the respective plan view of the proposed arrangement, as well as:  
* The formed angle \(\theta_{f}\) between successive frames;  
Figure 17: Ninth electrode station configuration—Section plan of six straight frames, adapted radially to a central base with guides. * The minimum distance \(d_{Sc}\) determined through Equation (39);
* The widths \(d_{Ox}\) and \(d_{Ox}^{\prime}\) of the electrode station critical zone, along the semi-axes Ox and Ox\({}^{\prime}\) from the beginning of the axes, which coincides with the centre of the central base, as obtained from the electrode station simulations;
* The lengths \(d_{Oy}\) and \(d_{Oy}^{\prime}\) of the electrode station critical zone, along the semi-axes Oy and Oy\({}^{\prime}\) from the beginning of the axes, as obtained from the electrode station simulations. It is noted that, due to the simplifying assumptions of the electric fields, in the present case, there will be no differentiation between \(d_{Ox}\), \(d_{Ox}^{\prime}\), \(d_{Oy}\), and \(d_{Oy}^{\prime}\). Taking into account, from analytical geometry, that to ensure a distance \(d_{Sc}\) between two consecutive points located on an arc \(\theta_{f}\) on a circle of radius \(R_{K1}\) with \(N_{frame}^{\prime}\) total points, it must hold that:  
\[\theta_{f}=\frac{360^{\ast}}{N_{frame}^{\prime}} \tag{41}\]  
\[\frac{ds_{c}/2}{R_{K1}}=sin\bigg{(}\frac{\theta_{f}}{2}\bigg{)}\Rightarrow R _{K1}\geq\frac{ds_{c}}{2\times sin\Big{(}180^{\ast}/N_{frame}^{\prime}\Big{)}} \tag{42}\]  
Figure 18: Ninth electrode station configuration—Floor plan of six straight frames, adapted radially to a central base with guides. Therefore, through the implementation of Equation (42), for six frames, it holds that:  
\[R_{K1}\geq ds_{c} \tag{43}\]  
The respective surface \(S_{cr-VIX}\) is calculated through Equation (40). It is a completely different solution that places the electrodes at a greater depth and limits the intervention on the coast, requiring, however, a more special civil engineering project.