Electricity + Control February 2019

CABLES + ACCESSORIES

On the positive side, this inhospitable landscape is not home to any voracious animals that could gnaw away at the cable. The job of selecting the right cable fell to Bergur Bergsson. The engineer from Iceland’s meteoro- logical office went looking for a Vaseline-filled Eth- ernet cable with four twisted-pair cores, screening and a robust outer sheath. Bergsson’s colleagues have been using these cables in seismic measure- ment networks for 15 years, such as in a similar project on Vatnajökull, Iceland’s largest glacier. The decision to choose LAPP was largely thanks to the company’s good website and search function. “We were able to find exactly what we were look- ing for”, says Bergsson. “LAPP is also a trustwor- thy brand in the cable sector”. Watertight in every direction On the LAPP website, Bergsson found an outdoor cable for connections in telecommunication. The

Across razor-sharp volcanic rock The distances between the wind turbines, data transfer centres and the seismometers are rel- atively short. In many sectors, LAPP is known for not having minimum order quantities. This al- lowed the scientists to order the three kilometres of cable they needed for their entire installation. But the main argument in favour of the LAPP ca- ble was its robustness. The hard volcanic stone makes it impossible to install a cable underground, meaning it has to be rolled out over razor-sharp rocks. Here it has to withstand mechanical abra- sion and sub-zero temperatures in the Icelandic winter. Snowfall can also occur all year round. Another important factor is heat. Above the thin crust of the Mid-Atlantic Ridge, the rock can be very warm. Geophysicists have already measured temperatures of 50 degrees Celsius at a depth of just half a metre. Furthermore, highly corrosive gases flow out of the ground in some places.

Author, Bernd M ü ller.

Figure 4: At 1 300 m. Source: Icelandic Meteorological Office

6 Electricity + Control

FEBRUARY 2019