Balance of Plant (BoP) inspections

Managing the safety, risks and maintenance of wind turbines starts with the condition of the structure below water and at sea level. Balance of Plant inspections focus on the structural condition of critical components such as the transition piece, foundation and secondary steel structures in the splash zone. In these areas, cyclic loading, corrosion and impact have a direct effect on fatigue, connections and safe access.

By carrying out targeted inspections for corrosion, cracking, bolted connections and coating condition, a realistic and technically substantiated picture of the asset’s condition is created. This enables BoP inspections to support asset owners and operators in managing risks and substantiating maintenance, availability and the service life of wind turbines.

Control Union

    Certainty and control for wind turbines

    Control Union combines several certified inspection disciplines within a single BoP campaign, including visual inspections and condition assessments, NDT and wall thickness measurements, bolt and flange inspections, and certified coating inspections.

    Inspections are carried out using rope access, drones and remote monitoring, tailored to the location and risk profile. This integrated approach reduces mobilisation efforts and provides a complete and consistent overview of the asset’s condition through a single inspection partner.

    Three offshore wind turbines standing in the sea, with clear blue sky. Wind Turbines at Sea. Sustainable energy production. Green Energy, clean power, clean energy concept.

    In addition to BoP inspections, we also offer the following services for wind turbines:

    Statutory inspections are legally required, periodic safety inspections of work equipment and safety systems on offshore wind turbines, such as personnel lifts, ladders, fall protection systems, anchor points and lifting equipment. These inspections cover all equipment and provisions used during maintenance and crew transfer on the turbine, ensuring that the workplace is demonstrably safe and complies with the applicable occupational health and safety requirements. Read more.

    Structural condition of BoP components

    Inspections of the transition piece, foundation and secondary steel provide insight into loading, damage and integrity under offshore conditions.

    Control Union
    1.

    Focused on critical areas of the turbine

    Inspections focus on transition pieces, foundations and boat landings, where wave loading and corrosion are at their highest and damage occurs most quickly.

    2.

    Focus on demonstrable damage patterns

    Each inspection targets visible and measurable damage such as corrosion, cracking, loosened bolted connections and impact damage caused by vessels.

    3.

    Scope tailored to the wind farm

    The inspection scope is defined based on the specific wind farm, the structures present and the risk profile, ensuring that only relevant components are inspected and that results can be applied directly.

    4.

    Structure and access in a single inspection

    Structural components such as the transition piece and secondary steel are inspected together with access systems such as ladders and platforms, reducing the number of mobilisations required and creating a complete overview.

    5.

    Applicable within the wind farm

    BoP inspections are carried out on turbine-related structures within the wind farm and, where applicable, on offshore substations with comparable structures and loading conditions.

    The proof to your promise

    Toward control, insight, and certainty

    The strength lies in the combination of inspection expertise, advanced data systems, and global practical experience.

    Step 1

    Prior to the campaign, an intensive scoping phase is carried out in which client protocols, inspection objectives and reporting requirements define the full inspection scope.

    Step 2

    Inspections are performed using rope access, drones or remote monitoring, selected to match the structure, offshore conditions and risk level.

    Step 3

    All findings are documented in a clear report aligned with client specifications, providing condition statuses that support well‑informed maintenance and asset decisions.

    Control Union
    Our Balance of Plant inspections focus on structural response, degradation and failure mechanisms under real offshore loading conditions.
    Bernie Harms – Control Union
    Proof to your promise

    Frequently asked questions

    BoP inspections cover foundations, transition pieces, boat landings, access systems, secondary steel, coatings and, where relevant, offshore substations. Structural steelwork checks are combined with inspections of work platforms, ladders, handrails and fall-protection systems.

    Legislation requires asset owners to maintain a safe workplace but does not prescribe a fixed inspection interval. Frequency is determined by the owner based on asset condition, risk profile and operational exposure.

    Reports document all findings with a clear condition status per inspected element. Layout and detail level are aligned with client requirements, ensuring results are practical and directly usable for maintenance decisions.

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