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Had installation vessel itself had to retrieve monopiles in Sassnitz, the transport rotation would have taken at least 5 hours. Not counting the time it takes loading the ship. These successful tests, both in the German Bight and not least by Rügen in the Baltic Sea, made development manager at Bugsier, Sven Schröder, along with Finnish Wärtsilä German department and others “brainstorm”. The logistics for offshore wind farms could be solved in a smarter way. A charter of an installation ship costs an average of 200,000 euros a day. Therefore, these ships are a huge expense in the installation phase. The solution is immediate, says Sven Schröder to Maritime Denmark. LACK OF EFFICIENCY The proposals have been many, including the development of a barge-type with a Jack-Up System to be dragged to the installation vessels and be jacked up to working height, where the crane on the installation vessel would be able to supply themselves with mono piles, towers, gearboxes and blades. In this way, installation ship could work regardless of weather conditions in water depths up to 50 meters. The idea sounds thoughtful and interesting, but would not have helped to reduce costs, which is of course the primary objective. On the contrary, the proposal would double the construction cost offshore. To build a barge with a Jack-Up System would also require a large number of employees on board to operate it and it would not have the required efficiency. TUGBOATS Sven Schröder and his team of specialists in Bugsier Offshore and Wärtsilä now believe to have found the solution using the towing technique. The technique is well known from, for example. Vattenfall and DONG transport of coal from Enstedværket in Aabenraa in Southern Jutland to various Danish power plants. Here, they connect either tug boat Joulius or Calorius on the stern of a barge, which can then be pushed

to the destination, either Fynsværket in Odense Fjord or after a new supply of coal in Poland. Bugsiers and Wärtsilä’s proposal is to build a completely new and innovative Jack-Up installation ship J-LASH (Jackable Lighter Aboard Ship, ed.), With all the facilities know from existing ships except that the working deck is now a ship dock. JUST IN TIME The purpose of the new installation vessel is to place it at the wind park under construction. With the likewise purpose-built barges to fit the docks internal dimensions, the installation vessel pulls the barge into position. The tugboat is then reversed and connected to the barge and backed into the dock stern first, which is adapted the dock edges. The tugboat clears the barge. Then, everything is lifted to working height and the installation vessel can continue the work of putting up the turbines. The turbines are completed and ready from the port and transported by barge as items just in time, Sven Schröder explains. After delivery of the barge and elements, the tugboat continues to the next loaded barge, etc .. According to the calculations, not only will this save storage space in the base port

because the technique is an ongoing process, but will also save staff and time. This is despite the fact that towing the barge takes significantly longer to / from the J-LASH vessel than the time a traditional installation ship uses. The speed is usually around 12 knots. GREAT FLEXIBILITY Nowadays, the whole process begins with the installation vessel loading - typically in Esbjerg sailing to the wind farm and installing turbines, then returning to port for the next load. This is costly, especially in terms of personnel due to the idling between the picking up and bringing turbines to the wind farm. - The use of the barge system will in addition to the previously argued savings also mean greater flexibility, Sven Schröder explains. We are no longer dependent on deep water in the ports. This means that the logistics can be adapted to the land-based infrastructure in order to minimize crossing time from A to B with the barges and tug to the J-LASH ship’s position. This also creates the possibility of ports which so far have not been considered as suitable base for offshore wind turbines due to low water depth, to be considered because of a better land based infrastructure

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danish maritime magazine

Dmm 4 16  

Welcome to the Danish Maritime Fair 2016: In this issue of the Danish Maritime Magazine we focus on two pavilions; the pavilion of the Funen...

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