Glass fibre sea cable permitsrapid data transmission through Lake Constance

Mönchengladbach, 22 November 2007 – The car ferry “Fontainebleau” owned by Stadtwerke Konstanz GmbH which set out from Constance around 5 o’clock on 19 November had an unusual cargo on board. Instead of vehicles or foot passengers, the converted ship carried a fibre optic cable, almost 30 tons in weight, which was to be laid on the bed of Lake Constance. It will ensure rapid communication between Friedrichshafen and Constance. With a length of 26 kilometres, the cable was manufactured and delivered in one piece. Beneath its robust sheath, it contains four stainless steel bunched conductors, each one with 48 monomode fibre optic cables. Each one of these is capable of ultra-quick transmission of large data flows, digital television signals and an almost unlimited number of telephone conversations. Nexans Deutschland Industries GmbH & Co. KG, Mönchengladbach received the order for the entire project from Stadtwerke Konstanz GmbH.


Protection of the Lake Constance drinking water reservoir and of the environment ensured


A condition for receiving the order was that the materials used must not harm the quality of the drinking water as many towns and communities, right up to the northern border of Baden-Württemberg, procure their water from Lake Constance. Care also had to be taken to ensure that laying the cable would not harm any migratory or breeding birds, fish spawn grounds or the plant growth near the river bank. Stadtwerke Konstanz GmbH would now like to hire out the data transmission capacities of the fibre optic cable. For example, Internet carriers which offer high-speed Internet access or companies which require a rapid dedicated line can benefit from the additional transmission capacities. Initially, 144 of the 192 fibres are to enter operation; the remaining ones will form the back up for the future.


Special team laid around two kilometres of fibre optic sea cable per hour


The laying of the fibre optic cable, which was manufactured in the Nexans factory at Rognan, Norway, proceeded without a hitch thanks to the in-depth planning and preparatory work. The ferry was en route from Friedrichshafen to Constance for ten hours only. A satellite-assisted location system ensured that it remained in the correct location, and reference points on land were also used to determine its location. A team which was sent by Nexans Norway and which has considerable experience in laying products on the open sea headed the laying process, because even inland waters have their perils. Lake Constance is up to 250 metres deep. This meant that the cable had to be lowered with perfect pacing in order to land smoothly on the bed of the lake. If it had not been for the device which was specially welded to the ferry, the cable’s dead weight would have caused it to sink in an uncontrolled manner because, even in the water, each metre pulls downwards with a weight of 600 grams.  Laying the cable on land would have meant bypassing the lake and required excavation work which would have been disproportionately more expensive than laying the cable in the lake.


Installation involved cooperation at an international level


In addition to Nexans in Mönchengladbach, a team from Stadtwerke Konstanz GmbH and the installation team from Norway, employees from Nexans in Switzerland were also involved. They will connect the fibre optic cable in the coming days. But it must first of all be secured in the areas near the banks of the lake. Close to Constance, the cable will be driven into the shallow ground so that it cannot slip, and a plastic pipe will offer protection in the ferry area. Near Friedrichshafen, concrete shells prevent ship navigation or objects from causing damage and ensure a secure hold for the cable. Following this, the cable will be laid on land up to the system points where the sea cable is connected to existing data networks.

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Nexans Germany is one of the leading cable manufacturers in Europe. The company is offering an extensive range of high performance cables, systems, and components for the telecommunications and energy sectors, rounded off by superconducting materials and components, Cryoflex transfer systems and special machinery for the cable industry. Producing at manufacturing plants with 6.700 employees in Germany and abroad, the sales in 2006 amounts to 953 Mio Euro. The full integration into the Nexans Group Nexans Germany also benefits from excellent opportunities to use the available synergies in all corporate fields, which not only applies to worldwide projects but also to research and development, the exchange of know how, and to other areas.

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