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Maintenance on the high seas

The technical installations for the exploitation of wind energy are subject to extreme challenges: wind, waves and the salt content of the air and water damage the installations. The maintenance of the installations in these environmental conditions is just as demanding.

Sleeves Sleeves connect the submarine cable sections.

Cable repairs during swells

Although it is buried one metre deep in the sea floor, the cable can be damaged by ship anchors. When this happens, tests are conducted from the shore in order to accurately locate the failure. A repair ship heads out, lifts the cable from the sea floor and disconnects it at the point of damage.


Both cable ends are reconnected by means of an inserted cable section and junction boxes and lowered onto the sea floor. Finally, a series of tests is carried out to ensure that the repaired cable is functioning properly.

Supply, maintenance and emergency shelter: the substation platform

Repair and maintenance works on the platform are easier - provided than the platform can be reached. Huge seas and storm can make landing by ship or helicopter impossible. Platforms located far from the coast are usually reached by helicopter if they are equipped with a landing pad.

In the event that the team is stuck on the platform after the maintenance works, there are sufficient sleeping quarters and food available. Bigger wind farms can even support a permanent service team on the platform.


Christian Brehm

Public participation

Christian Brehm
Tel: +49 30 5150-3556
Fax: +49 30 5150-3112
E-Mail: christian.brehm@50hertz.com


Submarine cables

150-kV submarine cables transport the current generated at high sea to land, where it is fed into the transmission grid of 50Hertz. The cables, which are calculated and adapted individually for each connection, have a diameter of up to 25 cm and weigh approximately 100 kg. The cables are so-called three-conductor cables. Each single conductor consists of the actual copper conductor, the conductor screen and insulation screen to control the fields and a high voltage insulation made of cross-linked polyethylene (XLPE). A fibre-optic cable is integrated in the submarine cable for the data transmission of measurement and control signals. The cable core is coated with galvanised steel wires protecting it from mechanical damages, such as ship anchors.