Teil B - Minimum Requirements on geological survey 
19 
Table 6: Requirements of magnetometers or active metal detection systems (recommended). 
Geological survey 
Objectives 
• Primary inspection of the study area for wrecks, cables in and out of oper 
ation, metal parts and other hazardous objects such as e.g. ordnance 
(provided it can be detected) 
Scope 
• Depending on necessity in accordance with the findings of the Desk Study 
(Stage 1, see Table 1) 
• In any case within ammunition prone areas and areas close by, sections 
corresponding to the seismic profile grid or covering the whole area if nec 
essary 
Timing 
• If required 
Method 
• Magnetometer 
• If ordnance is suspected, or within areas where munitions are suspected, 
then within a gradiometer arrangement 
• Resolution <0.1 nT 
• Alternatively: an active metal detection system which measures total inten 
sity 
• Cruising speed: max. 4 kn 
• Use up to a maximum sea state of 4 
• The altitude of the magnetometer over the ground should be chosen de 
pending on the geophysical study findings. If ordnance is suspected, then 
lower than 4 m. 
Presentation of 
results 
• Map with investigation findings 
• List of anomalies discovered incl. comparison with the findings of SSS 
investigations. The data must also be submitted in digital format and with 
sufficient supporting documentation. 
6 Offshore stations 
Offshore converter stations are individual structures which require individual geological sur 
vey. Survey must be provided in a comprehensive manner adapted to the size of the construc 
tion site in accordance with Part B, Sections 4 and 5. 
Geological survey is not necessary for offshore substations or other stations within the planned 
wind farm. 
7 Geological report 
7.1 Purpose 
The findings of geophysical recordings and the preliminary geotechnical investigation are 
compiled together and assessed in the geological report. The report provides a basis for fur 
ther planning and contains a description of the geological model upon which the structures 
should be erected. It should be set up from an engineering geological point of view and 
should, together with geotechnical documents (see Part A, Section 2), serve as empirical evi 
dence for validation of the planned sites and for selection of suitable foundation types.