Sofia UXO identification

James Fisher Renewables (JF Renewables) was contracted by Sofia Offshore Wind Farm Ltd (SOWFL) to carry out target identification of 26 potential UXOs and potential archaeological targets in the nearshore section of the Sofia Offshore Wind Farm export cable route from; mean high water springs – vertical tidal datum up to KP13 in accordance with Sofia’s current consent agreements and marine licence.

The 1.4 GW Sofia Offshore Wind Farm sited on the shallow central area of the North Sea known as Dogger Bank, is the largest offshore wind project in RWE’s current portfolio.

JF Renewables mobilised the DP2 vessel, MV Voe Vanguard, equipped with: a survey and positioning spread, a free swimming Triton XLX work class ROV complete with associated tooling and sensors and a team of highly experienced project personnel to safely carry out the target identification campaign in the challenging nearshore environment.

Voe Vanguard from the beach Image credit RWE

The challenge

  • Shallow water (nearshore)
  • Strong tidal currents
  • Shallow drafted vessel required due to shallow water
  • Challenging weather conditions, work was carried out during the months of September/October
  • Short lead in to project

The solution

  • Shallow water (nearshore) - project execution planned to coincide with high water neap tides
  • Strong tidal currents - more powerful work class ROV engaged (Triton XLX) as opposed to initially proposed observation class ROV (Cougar)
  • Shallow drafted vessel (required due to shallow water) - experienced multipurpose vessel MV Voe Vanguard was chartered which has experience in these exact types of operations, ROVs and these tidal and environmental constraints
  • Challenging weather conditions with the work carried out during months of September/October - more powerful vehicle used in order to get the most out of the available tidal windows, thus expediting the scope completion and de-risking exposure to poorer weather conditions which can be expected in the latter parts of the year
  • Short lead into project - planning and resourcing

The results and benefits

  • Safe and successful completion of the scope in line with customer expectations ahead of the poorer weather conditions which can be expected in the winter months
Sofia UXO 4 1

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