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Risk Matrix — Offshore Wind Farm Construction and O&M Register

An owner's register for a fictional 1.2 GW offshore wind farm spanning grid, cables, installation, turbines and consents: controls cut exposure from 94 to 51 (−46%), and a delayed grid connection stays High 12 above the Medium appetite, with an interim 400 MW connection offer as the treatment. Illustrative register.

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Dogger North 1.2 GW offshore wind farm — construction and O&M risk registerOwner's register at final investment decision plus 12 monthsHEAT MAP · residual position, arrows from inherent11LOWLOW22LOWLOW33LOWLOW44LOWLOW55MEDIUMMEDIUM22LOWLOW44LOWLOW66MEDIUMMEDIUM88MEDIUMMEDIUM1010HIGHHIGH33LOWLOW66MEDIUMMEDIUM99MEDIUMMEDIUM1212HIGHHIGH1515HIGHHIGH44LOWLOW88MEDIUMMEDIUM1212HIGHHIGH1616VERY HIGHVERY HIGH2020VERY HIGHVERY HIGH55MEDIUMMEDIUM1010HIGHHIGH1515HIGHHIGH2020VERY HIGHVERY HIGH2525VERY HIGHVERY HIGHOW-07OW-06OW-03OW-05OW-08OW-02OW-08OW-07OW-04OW-01OW-03OW-06OW-01OW-02OW-05OW-04Rare<5%1Unlikely5–20%2Possible20–50%3Likely50–80%4Almost certain>80%51Insignificant<£0.5m2Minor£0.5–2m3Moderate£2–10m4Major£10–50m5Severe>£50m or fatalityLIKELIHOOD →IMPACT →R1residual position (after controls)R1inherent positioneffect of existing controlsappetite boundary · red ring = above it25L×I score and rating bandRISK PROFILE BY BANDInherentResidual (current)Very high0 → 0High6 → 1Medium2 → 5Low0 → 2Low 1–4 · Medium 5–9 · High 10–15 · Very high 16–25EXPOSURE Σ L×I51residual, after current controlsfrom 94 inherent · −46%HIGHEST RESIDUAL RISKOW-01Grid connection delayed by thetransmission operator12 · Highowner Grid Connection ManagerRISK APPETITEMedium or below1 risk above: OW-01Risk register8 risks · sorted by residual rating, then score#IDRISK, CONTROLS AND ACTIONSOWNERINHERENTRESIDUALTARGETCHANGEGRIDGrid connection delayed by the transmission operatorConnection agreement with delay compensationMonthly interface meetings with the transmission operator→Agree an interim connection offer for the first 400 MW — due 2027-09 ·Commercial Director1OW-01Grid ConnectionManager3 × 515 · High3 × 412 · HighABOVE APPETITE2 × 48 · Medium−3−20%↑ risingCABLESExport cable failure in the first five yearsBurial to 1.5 m depth from a cable burial risk assessmentCable protection systems at all third-party crossingsSpare export cable held in storage2OW-02Electrical PackageManager3 × 515 · High2 × 48 · Medium—−7−47%HEALTH & SAFETYCrew transfer injury stepping over from a crew transfer vesselMotion-compensated gangway used above 1.5 m significant wave heightGWO sea survival and transfer training for all technicians3OW-03HSE Manager3 × 412 · High2 × 36 · Medium—−6−50%TURBINESBlade leading-edge erosion earlier than designedLeading-edge protection shells fitted at the factoryAnnual drone inspection of every blade4OW-05Asset Manager4 × 312 · High2 × 36 · Medium—−6−50%FOUNDATIONSFatigue cracking in monopile secondary steelStructural health monitoring on twelve sentinel foundations5OW-08Asset Manager2 × 48 · Medium2 × 36 · Medium—−2−25%INSTALLATIONJack-up vessel weather downtime beyond the P50 allowanceInstallation programme planned on P90 weather windowsWeather-risk sharing in the vessel charter6OW-04Marine Coordinator4 × 312 · High3 × 26 · Medium—−6−50%SEABEDUnexploded ordnance found on the cable routeUXO survey with a target clearance campaignRoute micro-siting around confirmed targets7OW-06Marine PackageManager3 × 412 · High2 × 24 · Low—−8−67%CONSENTSMarine mammal noise limit breached during pilingSoft-start piling with double bubble curtainsMarine mammal observers and passive acoustic monitoring8OW-07EnvironmentalManager2 × 48 · Medium1 × 33 · Low—−5−63%FINDINGS8 risks rated — inherent 6 High, 2 Medium; after current controls 1 High, 5 Medium, 2 Low.Total exposure Σ(L×I) falls from 94 to 51 after current controls — a 46% reduction.Controls move 6 of 8 assessed risks into a lower band; 2 keep their inherent band.1 of 8 risks sits above the Medium appetite on residual rating — OW-01 (High 12); it has a treatment action.Highest residual risk: OW-01 Grid connection delayed by the transmission operator — High 12, owner Grid Connection Manager.Controls do most for OW-06: 12 → 4 (−67%).Illustrative register for a fictional project; costs and ratings are examples, not an assessment.

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title "Dogger North 1.2 GW offshore wind farm — construction and O&M risk register"
subtitle "Owner's register at final investment decision plus 12 months"
likelihood-levels: Rare (<5%), Unlikely (5–20%), Possible (20–50%), Likely (50–80%), Almost certain (>80%)
impact-levels: Insignificant (<£0.5m), Minor (£0.5–2m), Moderate (£2–10m), Major (£10–50m), Severe (>£50m or fatality)
bands: Low 1-4 green, Medium 5-9 yellow, High 10-15 orange, Very high 16-25 red
appetite: Medium
note "Illustrative register for a fictional project; costs and ratings are examples, not an assessment."

risk OW-01 "Grid connection delayed by the transmission operator"
  category: Grid
  owner: Grid Connection Manager
  likelihood: 3
  impact: 5
  control "Connection agreement with delay compensation"
  control "Monthly interface meetings with the transmission operator"
  residual: 3x4
  action "Agree an interim connection offer for the first 400 MW" due: 2027-09 owner: "Commercial Director"
  target: 2x4
  trend: rising

risk OW-02 "Export cable failure in the first five years"
  category: Cables
  owner: Electrical Package Manager
  likelihood: 3
  impact: 5
  control "Burial to 1.5 m depth from a cable burial risk assessment"
  control "Cable protection systems at all third-party crossings"
  control "Spare export cable held in storage"
  residual: 2x4

risk OW-03 "Crew transfer injury stepping over from a crew transfer vessel"
  category: Health & safety
  owner: HSE Manager
  likelihood: 3
  impact: 4
  control "Motion-compensated gangway used above 1.5 m significant wave height"
  control "GWO sea survival and transfer training for all technicians"
  residual: 2x3

risk OW-04 "Jack-up vessel weather downtime beyond the P50 allowance"
  category: Installation
  owner: Marine Coordinator
  likelihood: 4
  impact: 3
  control "Installation programme planned on P90 weather windows"
  control "Weather-risk sharing in the vessel charter"
  residual: 3x2

risk OW-05 "Blade leading-edge erosion earlier than designed"
  category: Turbines
  owner: Asset Manager
  likelihood: 4
  impact: 3
  control "Leading-edge protection shells fitted at the factory"
  control "Annual drone inspection of every blade"
  residual: 2x3

risk OW-06 "Unexploded ordnance found on the cable route"
  category: Seabed
  owner: Marine Package Manager
  likelihood: 3
  impact: 4
  control "UXO survey with a target clearance campaign"
  control "Route micro-siting around confirmed targets"
  residual: 2x2

risk OW-07 "Marine mammal noise limit breached during piling"
  category: Consents
  owner: Environmental Manager
  likelihood: 2
  impact: 4
  control "Soft-start piling with double bubble curtains"
  control "Marine mammal observers and passive acoustic monitoring"
  residual: 1x3

risk OW-08 "Fatigue cracking in monopile secondary steel"
  category: Foundations
  owner: Asset Manager
  likelihood: 2
  impact: 4
  control "Structural health monitoring on twelve sentinel foundations"
  residual: 2x3