The correct calculation of forces and moments caused by wave action over crown wall structures is critical for their design. There are several existing equations for this, some of which are sanctioned in practice as it is the case for Jensen (1984) and Bradbury et al. (1998), Günback and Gökce (1984), Martin et al. (1999), Berenguer and Baonza (2006), and Pedersen (1996) and Nørgaard et al. (2013). These equations are the main tool for the design of breakwater crown walls and their accuracy is crucial to ensure the stability of the crown wall, especially when considering the sea level rise due to climate change and the possible damage of the armor, since both aspects are not usually considered in most original design studies. In a scenario of climate change, it is very important to estimate the possible changes in security factors due to both these aspects, comparing the results with the original design ones. This paper has as main objective to analyze it for the case study of Ericeira rubble mound breakwater in Portugal. For this, a comparison of the results using those equations and different scenarios including the current, considering sea level rise and armor damage, were performed to extract some conclusions: the increase in the sea level in the case study was not significant and therefore its incidence is very small; and the damage to the main armor by losing pieces at the berm is much more important in this case study, so it is essential to carry out the proper maintenance of the design section. On the other hand, horizontal forces are more conservative using Pedersen and Nørgaard equations, obtaining the lowest value with Martin. Regarding uplift pressures, Martin gives the lowest value, while the most conservative values are given by Günbak and Gökce’s for two scenarios, and Pedersen and Nørgaard for the other two scenarios. Furthermore, the sliding safety coefficient is more conditioning than overturning the safety coefficient in all the scenarios.

The evaluation of high-voltage groundwall insulation aged under long-term operating conditions is addressed using three sets of Roebel bars removed from large hydrogenerators after several decades of service. To cover an important cross-section of the possible operating regimes for typical hydros, the units involved in the study were selected to represent (i) the air-cooled Pumped-storage, (ii) the air-cooled base-load and (iii) the water-cooled base-load service regimes. Experimental techniques were used to permit assessment of the insulation condition under visual, electrical and morphological aspects. Contrary to what is usually assumed, the results suggest that the pumped-storage operating regime, with its repeated thermal-mechanical cycles of start-stops may create only minimum aging to the groundwall insulation while, in some particular cases, units operating at relatively low temperatures and under mild base-load conditions, may be found to exhibit a more severe insulation degradation in the long run.