Ports & Ships
After the complex planning and authorisation phase comes the real logistical feat. The construction of an offshore wind farm requires close attention to detail; all procedures need to be precisely coordinated and many specially adapted tools and technologies – such as specially built ships – come into play. The process involves assembling and loading individual components of gigantic proportions before transporting them to their final destination where they are then built. It all takes pace under challenging conditions; working in the North Sea means our installation team will have to face high waves and constantly changing weather conditions.
Drawing from past experiences
Wind power has long been one of Vattenfall's core areas of operation, which means we can draw on many years of experience, as well as a skilled team, when it comes to building wind turbines. During the DanTysk project we will mainly be applying knowledge gained during construction of Germany's first offshore wind farm, Alpha Ventus.
Esbjerg: the central port
Esbjerg is the most important port for the construction and operation of the DanTysk wind farm. It bears the same name as the town it is a part of (the fifth largest in Denmark) and is situated directly on the North Sea coast. This makes the port of Esbjerg an ideal location for the loading of pre-assembled wind turbines onto ships for their transport to the DanTysk offshore site. Its close proximity to the production sites where the individual turbine components will be manufactured means that the time needed for additional onshore transports can be reduced.
A premium hub for offshore transports
Esbjerg is a well-established harbour: it is already 120 years old and was once the country's most important fishing port. It still plays an important economic role today in terms of Danish offshore oil and gas extraction. The wind sector has become a particularly important segment in Esbjerg's port industry, in part due to the construction and commissioning of the world's first large-scale offshore wind farm: Horns Rev. Vattenfall also runs a control centre in Esbjerg which operates and supplies maintenance to approximately 900 turbines which the company operates over six European countries. This will also be the maintenance centre for DanTysk.
Dutch ports of call
The process of transporting the farm's foundation piles and offshore substation begins at Dutch ports which are situated close to the respective production plants. The monopiles will be built in Roermond before being transported along inland waterways to Vlissingen. Once there, they will be loaded onto the Seafox 5 to be transferred to the DanTysk construction site. The offshore substation, on the other hand, will be shipped from Rotterdam harbour in spring 2013. The wind farm's cables will be produced in Norway and loaded for transport in the Scandinavian harbour of Asker.
A highly-specialised fleet
Specially-selected ships will be used during the various construction phases of the DanTysk wind farm project. Alongside the five most important installation ships, several ships will be put to use throughout the course of the building phase which is set to last at least a year. These include vessels for material and crew transport as well as vessels to assist installation work. When construction work is at its peak, crew transfer ships will be needed on a daily basis to transfer crew members from Esbjerg to the construction site and around the wind farm. A construction site guard vessel will also be patrolling a safety zone surrounding the wind farm. Two newly-built crane ships (the Pacific Osprey and the Seafox 5) will embark on their maiden voyage to work on the DanTysk project.
Vattenfall will commission the Pacific Osprey from Danish company Swire Blue Ocean. It is one of the largest installation ships of its kind in the world and will be used for the transport and installation of the 80 Siemens wind turbines. Its unique design means it can operate in almost all weather conditions in accordance with the latest safety standards. It contains an engine which can generate a speed of up to 13 knots and can transport up to twelve turbine units at the same time – more than any other installation ship. An improved level of stability means the Pacific Osprey can place turbines onto the foundations in the North Sea even with 2.5-metre-high waves and a wind speed of up to 20 metres per second.
With its special design, this 151-metre-long multifunctional vessel will be able to take on the biggest challenges involved in constructing an offshore wind farm in waters with a depth of up to 70 metres. On the DanTysk project, this vessel will be used to install the foundations in the North Sea. Seafox 5's crane is designed to support a load of up to 1,200 tonnes.
This ship, owned by the Dutch company VSMC, is crucial for the internal cabling network within the wind farm which will link up the 80 wind turbines and connect them to the offshore substation. The Olympic Taurus will transport the cables from Norway to the construction site 70 kilometres off the island of Sylt, and will install the cable into the sea floor.
This is also one of VSMC's ships. It will be used to carry out cable installation work within the wind farm – a task which will require the use of several ships as well as a great deal of fine-tuning and attention to detail.
With a length of 183 metres and a weight of 5,000 tonnes, this is the largest ship that will be used in the construction of DanTysk. Fitted with state-of-the-art technology, this giant vessel will be deployed to install the offshore substation at sea.