Wind turbine installation vessel
A construction vessel as a short form of offshore wind turbine installation vessel, also called installation vessel is in contrast to the jack-up rig a special built for the creation and development of offshore wind turbines work boat with heavy duty crane and own for propulsion and dynamic positioning suitable strong engine and Propulsion. It also has lifting devices to operate independently of the swell, can.
Development of installer ships
Offshore wind energy has developed slowly, starting in Denmark and led to the use of jack-up platforms (1st generation) and at greater depths and distances to the coast occasionally also for the conversion of freighters to first installer ships (2nd generation). These were better than the jack-up platforms, but to be regarded as modifications only as a compromise.
Since about 2005, in Germany, offshore wind energy is transferred into an accelerated development. To the UK offshore wind farms originated close to the coast, as in Denmark. The German decision to phase out nuclear power generation plants and the requirements, offshore wind farms in the German EEZ to approve only at large distances from the coast, is the fact that these wind turbines are to be installed in large water depths of 15-40 m. With the experience of the " Tags" produced designs for the installation vessels of the third generation with large capacity ( up to 1500 t capacity cranes ) and ship speeds up to 15 knots. This installation vessels have thus developed into a separate vessel type and can no longer be described as jack-up rigs, but are therefore also to the genus Heavy Lift Vessel ( heavy transport ship).
The 4th generation of offshore wind turbine installer ships do not have a jack-up system, but are considered semi-submersible seegangsunabhängig possible. Because of the non -tested installation concept and resulting increased investment risk -tion no such ships have been built yet.
Meanwhile, the 5th generation of OWEC installer ships is planned. This is the task of transporting the individual elements for the construction of the facilities of the port on the mainland to the building site on site by the installer ship to multiple, are transmitted by tractor moving barges. Several barges commute between the port and the construction field and lead to move materials through. The fact that the installation vessel can remain on the construction site and the preparation of the components does not have to interrupt for the advection, expected to have a significant time - and thus also cost savings. Such installation vessels have instead a separate deck area over a Ladeschwimmdock that in the slightly upscale, beballasteten state can be flooded on site. In this state, the feeder barges can from ending up with the material. The legs of the ship installer will now be further extended during the ballast tanks and the loading dock to be pumped dry. The installation vessel can then begin the installation of the charge brought. Because the feeder barges can start by their much smaller size of the ports in the place of manufacture of wind farm elements is hoped that by avoiding base ports further cost savings.
Characteristics of installer ships
Features include a large deck area, pontoon bridge structures to accommodate crew and fitters and most importantly, a powerful on-board crane with lifting capacity of 500-1500 t who comes to the construction of offshore wind turbines for use, as well as a helicopter platform. In addition, facilities for dynamic positioning (DP ) are present, so that the installation vessel can be positioned without external help at the respective locations via GPS, to then establish Hife with the jack-up legs at exactly this place.
It is in the ships so-called jack-up vessels, also called jack-up vessels (so-called jack-up legs ) can, with the help of four to six hydraulically or electrically operated legs in a fixed position up in the sea. Only in the early days came in ships or semi-submersible SWATH design used, as these are less stable in the water.
During the trip, the legs are raised. It was only at the intended position, these are gradually lowered and placed on the seabed. Then the ship is lifted out of the water (usually 10 to 20 m depending on swell ) and anchored by its own weight. This provides the necessary stable work platform.
For the necessary tasks the installation vessels are equipped with a large heavy-duty crane. In addition there is a large building with accommodations for the crew and a helicopter deck for the crew change and rapid assistance or transportation accidents.