Offshore J-tubes / S-tubes

Curved tubes to support and protect the cables

J-tubes support and protect cables between the bottom of the sea and the upper part of the offshore wind foundation, where they are connected to the substation or offshore wind turbine.

J-tubes provide the necessary protection for the cables and are an essential part of any offshore wind foundation. The product consists of steel tubes that are bent into the required J- or S-shape to form the full length of a J-tube.

Kersten has a strong track record in the supply of J-tubes. We have successfully supplied J-tubes for various offshore wind projects in the North Sea, Baltic Sea, Irish Sea, Atlantic Ocean.

Production of J-tubes

Current J-tube sizes range from Ø457mm to Ø610mm in diameter. These tubes are supplied in seamless or welded condition depending on customer and end-user needs.
The tubes are bent according to the requirements of the project. When the bending radius allows, roll bending is used, as it is a reliable and the most cost-effective option. When even larger tubes (up to Ø1,016mm) are required, tubes can also bent by induction bending technology.

After bending, the tubes are cut to length to the required tolerances, including end chamfer or internal tapering. Along with the J-tubes, the support structure (tube supports, guides and bellmouths) is often supplied as a complete package.

Offshore track record