Turntable for the seacable intercalation

In the North-Sea about 45 kilometres north of the island Borkum, Germany´s first offshore-windpark is beeing installed. Until the end of this year, 50% of the wind enery converters are supposed to be ready to deliver energy to more than 10,000 households. For the realization of this task, highly precise technical procedures are necessary. Resistant seacables beeing kilometres long are in operation around the clock-and have to be ready at any time to guarantee a permanent grid connection of the wind energy converters in case of sudden failures. A task which is solved with the help of a turntable.

The principle behind this is easy: The offshore cable is delivered by ship, unwinded via a 450 metre long cable way and then mounted on the turntable. Like a record-player the cable-arm takes the inordinately large cables and piles them up to two meters high. The turntable consisting of 24 individual segments and with an external diameter of 24 meters has a carrying capacity of up to 1,700 tons.

In order to unwind the up to 22 centimetres thick cable, four hydraulic mechanisms are used which are able to move the steel giant on mounted rollers thus enabling the cable leading. “The construction beeing mainly flexible was a special challenge for us”, explains project leader Rainer Janssen. “It was important to consider the precise line direction of the cable which is unwinded like a snail”, says the employee of IHNEN, who designed and produced the turntable together with his team for a big German Transmission System Operator.