Structural Integrity of Offshore Wind Turbines Oversight of Design, Fabrication, and Installation - Special Report 305 (2011) / Chapter Skim
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6 Qualifications Needed by Certified Verification Agents
6 Qualifications Needed by Certified Verification Agents
Pages 109-126
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From page 109... ...
SURVEY OF QUALIFICATIONS FOR OTHER THIRD-PARTY REVIEWS Third-party reviews and verification activities are undertaken for various engineered systems, among them offshore oil and gas, marine, and land-based structural design (including wind turbines)
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From page 110... ...
Section (b) lists the information that must be included in the CVA "qualification statement," including the following: • Previous experience with third-party verification; • Previous experience with design, fabrication, or installation of fixed or floating offshore structures; similar marine structures; and related systems and equipment; • Previous experience with BOEMRE requirements and procedures; • Technical capabilities for the specific project and staff availability; • Size and type of the organization; • Access to necessary technology such as analysis tools and testing equipment; and • Level of work to be performed.
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From page 111... ...
Expectations of CVAs for the Installation Phase The primary installation phase activity (30 CFR 250.918) is to perform an independent review of the installation on the basis of "good engineering judgment." This entails reviewing installation plans and procedures and witnessing the installation operations from loadout and towing to launching, uprighting, submergence, and so forth.
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From page 112... ...
In some cases, there is no regulatory requirement for project certification, but the operator or developer may need certification to obtain financing or for other reasons. In these cases, certification is generally provided by an organization, such as Germanischer Lloyd or Det Norske Veritas, that has developed its own set of guidelines for designing, installing, and maintaining wind turbine facilities.
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From page 113... ...
One description of this type of peer review comes from the Los Angeles Tall Building Structural Design Council in its publication 2008 Alternative Design Criteria. The council proposes that each project convene a seismic peer-review panel to provide an "independent, objective, technical review of those aspects of the structural design" related to seismic performance.
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From page 114... ...
As in the case of offshore oil and gas facilities, a qualification statement is required that includes the following: • Previous experience with third-party verification; • Previous experience with design, fabrication, repair, or installation of offshore energy facilities; • Previous experience with BOEMRE requirements and procedures; • Technical capabilities for the specific project and staff availability; • Size and type of the organization; • Access to necessary technology such as analysis tools and testing equipment; and • Level of work to be performed. Unlike the regulations of 30 CFR 250, the offshore wind turbine regulations require that the verification work be directed by a registered professional engineer.
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From page 115... ...
Project-Specific Accreditation This approach is used by BOEMRE for offshore oil and gas CVA selection and is inherent in the proposed CFR language for offshore wind turbines. A CVA is nominated by the operator for each project and must be approved by the BOEMRE regional director.
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From page 116... ...
To implement an authorized list effectively there should be • A regular review of the authorized organizations, • A process for removal from the list, • A regular opportunity to add new organizations to the list, and • An auditing process to ensure that personnel performing CVA duties are those whose qualifications were cited to get on the list. An authorized list can be advantageous, although it may be just as burdensome for the regulator, given the work required to maintain the list and ensure that it is used properly.
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From page 117... ...
The following sections outline the committee's suggested expectations for a CVA qualified to perform each of the three review phases. The expectations are based on the direct experience of the committee members, reviews of existing guidance documents for offshore wind turbines, and CFR requirements.
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From page 118... ...
In contrast to the case for offshore oil and gas permanent structures, the inter action between the wind turbine's above-water structure and the sub structure and foundation has a dynamically driven response that must be considered in the design and understood by the CVA to ensure that it has been adequately addressed.
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From page 119... ...
2. Witnessing of installation operations including loadout, towing, launch ing, uprighting, submergence, and so forth.
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From page 120... ...
The amount of attendance required should be based on the complexity of the activity and the contractor's experience with similar activities. Other Aspects of CVA Qualifications The experiences of some committee members and information provided to the committee by presenters indicate that having CVAs for the design phase different from those for the fabrication and installation phases is acceptable in current offshore oil and gas practice.
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From page 121... ...
and that the CVA activities capture all necessary aspects of the project. FILLING THE EXPERIENCE GAP To date, no large-scale offshore wind turbine projects have been designed for or installed in U.S.
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From page 122... ...
Such a panel would need a range of expertise similar to that described in the section on offshore wind turbine CVA qualifications. Ideally, the panel would have expertise in design of offshore wind or oil and gas structures; offshore transportation and installation, particularly for fixed structures; and structural engineering and fabrication with a preference for experience specific to offshore wind.
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From page 123... ...
FINDINGS AND RECOMMENDATIONS FOR TASK III Task III of the statement of task calls for the committee review the expected experience level, technical skills and capabilities, and support equipment and computer hardware/software needed to be considered a qualified CVA. Findings, Task III Based on a review of the implementation of the CVA process for offshore oil and gas facilities, the proposed CFR language for an offshore wind CVA, and how other engineered systems implement third-party reviews, the following are the committee's key findings with regard to CVA qualifications.
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From page 124... ...
Identification, specification, and implementation of design limit states; b. Fatigue and strength design approaches, including the effects of coupled wind–wave dynamics; c.
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From page 125... ...
8. Experience with the use of project-specific CVA approvals in the offshore oil and gas industry indicates that project-specific approval of CVAs is better than maintenance of a list of BOEMRE-accepted CVAs.
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From page 126... ...
6. BOEMRE should actively participate in the IEC Wind Turbines Cer tification Bodies Advisory Committee as a means of staying informed on issues relating to wind turbine certification and the accreditation of CVAs.
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