Section 8 Support structure manufacturing surveillance

8.1 Module requirements

8.1.1 The purpose of this module is to undertake surveillance to verify that the project-specific support structures are manufactured in accordance with their approved design and to the intended quality. Surveillance comprises audit, inspection, and document reviews by the certification body.

8.1.2 It may be that part of the support structure is covered by the WT type certification (e.g. the main support tower). If this is the case, the principles described in Ch 2, 7 Wind turbine/RNA manufacturing surveillance should be applied in establishing the certification body scope for that part of the support structure.

8.1.3 According to IEC 61400-22 Wind turbines – Part 22: Conformity testing and certification and IECRE OD-502 Project Certification Scheme, the manufacturer of the main parts of the support structure must operate a quality system; the certification body should focus on the implementation of the system during the manufacture of the project-specific support structure.

8.1.4 IEC 61400-22 Wind turbines – Part 22: Conformity testing and certification and IECRE OD-502 Project Certification Scheme requires that the project certification body defines a project-specific surveillance scope based on a number of factors including (refer to Paragraph 9.9.2, IEC 61400-22 Wind turbines – Part 22: Conformity testing and certification and Paragraph 7.8.2, IECRE OD-502 Project Certification Scheme for a full list of factors):

any part of the support structure being covered by the WT type certification, including any conditions or outstanding work;
the extent to which quality systems cover the support structure manufacture, and certification of such quality systems (e.g. certified to ISO 9001 Quality Management);
the fabricator’s experience of delivering the project-specific scope;
the certification body’s experience with the fabricator;
the quantity and type of units in the project scope;
the extent of inspection by the applicant and its contractors;
availability of quality control documents; and
access to sub-contractor facilities and documentation.

8.2 Guidance on input requirements

8.2.1 In order for the certification body to define and plan the project-specific scope for their surveillance of the support structures manufacture, the applicant should provide the following:

WT type certification, if applicable, and supporting design documentation;
an overview of the support structure manufacturer’s quality systems including details of any certification (e.g. ISO 9001 Quality Management);
details of fabricator including locations and sub-contractors (and their scopes);
fabrication codes and standards;
fabrication schedule; and
details of the inspection and other assurance processes planned by the applicant and its contractors.

8.2.2 Inputs from the design evaluation (e.g. critical nodes/connections and other items) shall also be taken into consideration for the certification body to define and plan the project-specific scope for their surveillance of the manufacture of the support structures.

8.2.3 In order for the certification body to carry out their planned surveillance of the support structures, the applicant should provide (or provide access to) the following:

ITPs including indication of the planned reviews and intervention points of the applicant and its contactors;
manufacturing and testing plans and procedures;
manufacturing and quality control procedures (including welding, heat treatment and NDE);
sub-supplier quality system documents;
quality control document such as material certificates, material traceability records, operator qualifications, heat treatment records, weld procedure qualifications, NDE reports, test reports, inspection reports; and
details of deviations from requirements and their handling/approval.

8.3 Surveillance methodology

8.3.1 LR will review the ITP for the support structure, including the references to manufacturing procedures and the codes and standards referenced, and the indication of the planned reviews and intervention points of the applicant and their contactors. Based on the findings of this review LR will indicate the planned surveillance on the plan(s), as certification body. LR’s surveillance will tend to be less intensive for those parts of the support structure manufactured according to a certified quality system.

8.3.2 The marked-up ITP becomes the surveillance plan referred to in Ch 2, 8.1 Module requirements. It should include details of the sample size to be surveyed by the certification body, as applicable.

8.3.3 LR’s surveillance should be conducted and reported in accordance with the agreed plan, although the plan can be updated in the course of the manufacture in response to changes (e.g. to sub-suppliers or schedule) or to findings (e.g. areas of concern identified during surveillance activities).

8.3.4 The focus of the surveillance will be on acquiring evidence that the support structures are built in accordance with the approved design and to the intended quality, with reference to Ch 2, 5 Site-specific support structure design evaluation.

8.3.5 Attention will be paid to ensuring the manufacture follows the certified design (as evaluated and reported in the conformity statement for the relevant module and its supporting evaluation report). Any deviations from the certified design will need to be assessed, and may require elements of the design evaluations to be repeated by the certification body.

8.3.6 The surveillance will consider all primary and secondary structures, and include foundation structures (e.g. piles), mooring systems for floating installations and corrosion protection measures.

8.3.7 The surveillance will be conducted by a combination of audit (assessing the assurance processes), sample review of manufacturing records, and sample of inspections, in all cases focussing on areas of greatest risk. Items to be reviewed and/or surveyed include:

welding consumable certificates;
welding procedure specifications (WPS);
welding procedure qualification record (WPQR);
welder performance qualifications (WPQ);
non-destructive testing (NDT) procedures;
NDT operator qualifications;
special work procedures (e.g. shaping, hot forming);
material traceability reports;
weld traceability reports;
heating records;
NDT reports;
weld repair register;
dimension reports;
technical queries (TQ);
non-conformity reports (NCR).

8.3.8 An essential part of the surveillance is to verify material origin and quality, and its traceability through the processing stages. This applies to metallic and non-metallic materials, and will comprise a combination of document review and inspection to confirm that:

materials are certified according to BS EN 10204 Metallic products: Types of inspection documents type 3.1 or 3.2 or equivalent (type 2.2 may also be acceptable, subject to more intensive review and inspection by LR); and
the manufacturer is implementing a suitable identification system that enables all finished materials to be traced to the original source.

8.3.9 The sample review of manufacturing records will include confirmation that all personnel carrying out critical functions (e.g. welding, NDE) are qualified for the tasks they are performing.