Pipe laying of the 1,224 kilometre long Nord Stream Pipeline started in April 2010. Three pipe-laying barges were commissioned to work on the project:
- Saipem's Castoro Sei - for the majority of the route in the Baltic Sea
- Saipem's Castoro Dieci - for the shallow waters in Germany
- Allseas Solitaire - for pipe laying in the Gulf of Finland
Castoro Dieci Trench and Pipelay barge
The Castoro 10 is a working ship of the greatest Italian offshore service provider Saipem, a former subsidiary of the energy company Eni. Built in the Dutch shipyard Nederlandse Scheepsbouw 1976, it continues today under the flag of the Bahamas and is used as pipeline laying ship.
Castoro 10 has equipment, to dig a trench into which the pipeline is laid. With the "Diverless Jet Sled 1" can thereby trenches with a grave depth of 4.3 m, are generated in a water depth of up to 300 m. The Castoro Dieci is able to work in shallow and coastal waters, because it has less draught, which is the vertical distance measured from the lowest point of a ship's hull to the water surface. With no means of self propulsion, the vessel relies on towing and anchor winching for the travelling and manoeuvring. Its 8-point mooring system enables it to maintain accurate positioning during pipelaying.
The ship uses the S-lay method, to lay pipelines to a diameter of 60 inches. The two "Tensioner" thereby allowing a pulling force of 60 t. The processing of pipelines is provided by two stations, for chamfering the pipeline ends, a welding station and two stations for radiographic examination. At the end of the pipeline is still running the stations for surface coating.