Appendices 
125 
Repair 
This encompasses all measures to be taken in order to restore functionality after an incident. 
Restricted Area 
Restricted areas are areas that contain technical facilities that are important to both safety 
and operations that primarily require protection from unauthorised access and basic hazards 
in order to ensure these facilities function as expected at all times. Secondarily, preventing 
access to restricted areas may also protect untrained personal from specific hazards, such as 
areas where electrical equipment is operated and battery installations. 
Rotor/Nacelle Assembly (RNA) 
Part of an offshore wind turbine that is maintained by a support structure, see Figure 1 -1. The 
rotor/nacelle assembly consists of a nacelle and rotor blades. The RNA includes the screw 
connection to the tower flange that is the interface to the tower which is part of the support 
structure. The fixtures/components in the support structure that are necessary for the opera 
tion of the RNA are part of the RNA (for example converter, transformer, switchgear cabi 
nets). 
Safety System 
The safety system is intended to ensure that the facility remains in a safe condition in the 
event of a disturbance. 
Scatter Diagram 
A scatter diagram is the graphical representation of an observed pair of values of two statisti 
cal attributes. These pairs of values are plotted into a Cartesian coordinate system which re 
sults in a bivariate point distribution (scatter). 
Scour 
Deepening of the seabed in the area of the foundation structure due to current-induced mine 
ral erosion. 
Secondary Structure 
Built-on accessories, machine-mounted accessories and fixtures that are attached to the pri 
mary structure and located outside the main power flow. 
Serviceability Limit State (SLS) 
State beyond which the defined conditions regarding the serviceability of a support structure 
or a component are no longer fulfilled. 
With regard to the foundation, this limit state is reached when an increase of the effects (ser 
vice loads) would lead to intolerably large total displacements or permanent displacements of 
the subsoil, the foundation elements or their components. 
Shear Keys 
Shear keys are welded reinforcements around the outer surface of a pile and at the connec 
tion piece in the grouted area. The shear keys are intended to increase the sustainability of the 
joint between the mortar and the steel. 
Soil (Loose Rock) 
Superordinate material designation for the different layers of subsoil.