Standards and Practices - Structural Integrity of Offshore Wind Turbines - page 48

working stress design approach, which is still accepted as a common design
practice in the United States. Allowable stress levels are defined for various
design conditions, including normal, abnormal, transport, and installation
on site, as well as earthquake and other rare conditions. Equivalent LRFD
criteria are also specified as an acceptable alternative.
The requirements for electric service platforms are addressed in the
ABS Rules for Building and Classing Offshore Installations. This document,
the first edition of which was published in 1983, is used in the verification
of bottom-founded structures worldwide.
GERMAN STANDARDS AND PROJECT
CERTIFICATION SCHEME
The Federal Maritime and Hydrographic Agency (Bundesamt für
Seeschifffahrt und Hydrographie, or BSH) is the agency in Germany that
decides on the approval of offshore wind farm development projects in the
North Sea and the Baltic Sea. It carries out the application procedure for
offshore wind farms in the German Exclusive Economic Zone, which is the
area outside the 12-nautical mile zone where most of the German offshore
wind farms will likely be installed.
Part of the approval procedure is to examine whether all installations
and structural components have been certified according to the BSH
standard Design of Offshore Wind Turbines (BSH 2007) , which was issued
in June 2007. This standard covers development, design, implementation,
operation, and decommissioning of offshore wind farms within the scope
of the Marine Facilities Ordinance and regulates the various structural
components of an offshore wind farm. It refers to another BSH standard,
Standard for Geotechnical Site and Route Surveys—Minimum Require-
ments for the Foundation of Offshore Wind Turbines, issued in August
2003. To develop these standards, BSH established a steering committee
that included technical experts in relevant fields and representatives of
three classification and certification societies (SGS, DNV, and GL).
BSH requirements for project certification are set forth for each of the
following phases:
Phase I. Development,
Phase II. Design,