With 20-year experience in the offshore wind market, we have developed our 10 FOB SWATH semi-submersible vessels (SWATH: Small Waterline Area Twin Hull). Our goal is to have the best personnel and vessels, using our experience to provide reliable services. Approved by DOCISO 9001, 14001, 45001AchillesEnvironmental Policies, GDPR, Danish Authority and DNV.


The 2 lower hulls are narrow and sharp and cuts through the waves. The pitching, rolling, and slamming are reduced due to the vessels design with ample distance from seawater to water deck. In rough sea and in semi submerged mode the vessels movements are significantly reduced, the problem with air intake to the propulsion units is avoided and the automatic moveable foils provide safe and comfortable operation.


Our special patented bow fender with moveable clamps used on the outside of the turbines docking poles keeps the vessels secured in the correct position and allows service personnel to use the “landings” in up to 2 m Hs.


  1. Fob Swath (“FS”) vessels have the following speed: FS 1 = 18 knots, FS 2, 3, 4, 5, 6 & 7 = 22 knots, FS 8 = 27 knots, FS 9 & 10 = 35 knots. If one propulsion unit should fail, the latter vessels continue with 25 knots.
  2. Our special vessels with a length of 32.5 m, have all Dynamic Positioning (DP).
  3. Sailing the same distance, the fuel consumption for our 32.5 m vessels at 30 knots are similar as our 25 m vessels at 22 knots. They can be powered with HVO(B100) or GTL fuels, reducing CO2 emissions up to 90% .
  4. Using the vessels’ large water jets, each of which provides 3000 liters of water per second, provides great safety when the vessels maneuver to the turbines and avoid  propeller vibrations and noise.
  5. Acceleration in accordance with the High-Speed Code 2000, with vertical acceleration under 1 G, lowest sea sickness index at 0.75 to 1.25, comfortable and safe seating as well as sound level below 60 decibels.
  6. Increased performance and extra bunker capacity, provides additional working days.
  7. Free deck space up to 75 m².
  8. Some of our vessels can carry up to 55 Industrial Persons (IP). Alternatively, we can provide accomodation vessels for 12 IP each with single cabin including WC., shower, etc. and additional 12 IP for day sailing.
  9. Change from CAT to SWATH mode or vice versa takes about 2 minutes.
  10. If one of our vessels need service, one of our available vessels can take its place.
  11. Marine Evacuation System (MES) with slides.
  12. Our vessels have hydraulic operated rescue net, which ensures the rescue of persons with one deckman.
  13. FS 8, 9 and 10 have hydraulic operated gangway and all our vessels have cargo crane.
  14. In our workshop, we have considerable spare parts and complete engines and gears.

Offshore Windservice A/S.
+45 978 880 00

Nordsökaj 51, 7680 Thyborön, Denmark

Billy T. Kristensen +45 50 800479



Associated companies: Odfjell Eiendom AS, Bergen, Norway, has long term investments in real estate with over 135 000 m² of commercial properties, part owners in custom built vessels for Bahamas, ice classed vessels for the Baltic Sea and special vessels for the wind industry.

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