Submarine Cables – C39D

Discussion Group C39D on Submarine Cables, has two presentations already lined up for the Fall 2019 ICC meeting. Abstracts follow. Make sure you are making your plans to join us in Scottsdale!

Installing Array Cables between Offshore Windturbines, from Land! FreeFloating over 40 km?, Willem Griffioen, Plumettaz SA

A method was developed to install energy cables into ducts and then further transport them through coupled pipes, like “tube post”, to any desired location, without the need to go there with material, equipment and labour. For this the cable is first installed with WaterPushPulling, where the cable is pushed into the pipe while water under pressure is injected into the pipe, resulting in a pushing force on a pig attached to the front end of the cable. Once the cable is entirely inside the pipe a rear pig is placed behind the cable and the cable is further transported by the sole action of water under pressure, a method called FreeFloating. Many advantageous applications exist, like installing cables into crowded city centres from suburbs and installing offshore cables from shore. A project is described, in Thyborøn (Denmark), where offshore wind turbines were connected by array cables. All cables could be installed from shore, even at Beaufort wind force 8! There is almost no limit to the FreeFloating distance over which cables can be transported. It will be discussed that installation speeds of 60 m/min and transport lengths of 40 km are possible when using 160/130 mm HDPE pipes. Also pipe diameter changes can be handled. For larger diameter pipes even longer distances are possible.

Update on Cigre Working Group B1.65, Installation of submarine cables, Søren Krüger Olsen, Ørsted

An update of the status from the Cigre B1.65 is given. The use of submarine cables is becoming more and more widespread. A need is seen for common guidelines concerning installation of submarine cables that will ensure that all central parties handling submarine cables have the same basis. Examples of parties are utilities, installers, manufacturers and involved consultants. On this basis it was decided late 2018 in the Cigre B1 study committee to start a working group with the aim to write a Technical Brochure concerning installation of submarine cables covering a wide range of aspect through out the life time of a submarine cable installation from early studies to removing the submarine cables after the service life. The cables covered by the WG will be power cables in the range of 30 kV to 500 kV (or even above) for both AC and DC application with various insulation systems. However, the aspects covered would even be relevant for lower voltages as well. The working group includes member from around the world, each representing their own country and not their affiliation.