Source: Nord Stream
Coinciding with the official end of the herring spawning season, Nord Stream is commencing preparatory construction works needed for laying the pipeline in the Bay of Greifswald. Construction of the cofferdam, which was installed onshore in April, will be continued offshore. At the same time, excavation work for the pipeline trench will be started.
“These works constitute the timely beginning of the next important phase of construction activities in the German sector of the Nord Stream Pipeline. We are now creating the conditions necessary to begin pipe laying, as scheduled, at the end of June,“ says Dr. Georg Nowack, Nord Stream Project Manager for Germany.
Nord Stream pledged not to start construction activities in the Bay of Greifswald before mid-May, in order to accommodate the herring spawning season. The onshore construction of the cofferdam has already been completed, and now the offshore section measuring roughly 550 metres will be constructed. For this, a temporary roadway on the eastern side of the cofferdam will be built. This requires special machines using the roadway to sink two parallel sheet pile walls into the ground, creating a 9.5 metre wide canal. Upon completion of the sheet piling, the ground between the walls will be excavated and the dredged material will be temporarily stored on the western side of the cofferdam. This process will be completed at the end of June.
Dredging of the pipeline trench at various positions along the pipeline route in the Bay of Greifswald will begin parallel to construction works on the cofferdam. Eight special excavators (two bucket excavators, three stilted excavators and three trailing hopper suction dredgers) will be used. Anchor tug boats, survey vessels, and transport barges will be used to support these efforts. Reusable excavated material will be temporarily stored in a pre-determined area east of Usedom. The clay that is created will be brought onshore and later used, for example, to upgrade the ferry harbour in Sassnitz. A total of more than 40 ships are in use at the start of construction.