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The Solitaire is currently one of the largest pipelayers in the world

Pipelayers are a type of work vessel that lay pipes for underwater pipelines for the transport of, for example, oil or gas on the water bed.

Structure and technology

Due to the necessary performance and the amount of material to be processed, pipe layers are usually relatively large floating units that are equipped with a complex infrastructure: Welding systems, systems for material testing and coating, as well as cranes to be able to handle the pipe segments, are installed on these ships . In addition, helicopters are used to transport personnel and ensure that urgent goods are replenished.

Laying technology

Welding two pipe segments on the pipe layer ( North Stream )
Today's pipe-laying processes, S-Lay processes for low and medium-sized and J-Lay processes for great water depths

On the ship, the pipes, which usually consist of 40  foot (around 12.2 meters) (see ISO container ) long segments, are welded together to form the pipeline. Today, laying takes place in a multi-stage process, in which two or more individual segments are first welded together until pieces of up to four individual segments with a length of 48.8 m (so-called quadruple joints or quadjoints ) have been manufactured. These pre - welded modules are then welded in the so-called fire line to form an "endless" pipeline. The testing of the weld seams by means of non-destructive material testing and the coating of the weld seams with plastics is also carried out in the Fire-Line.

In modern laying processes, a distinction is now made between S-Lay , J-Lay and R-Lay , which fundamentally differ from one another in the laying process and in guiding the pipeline during laying. While the S-Lay method is mainly used for shallow and medium water depths, the J-Lay is mostly used for great water depths. The depth record, however, was achieved in the S-Lay.


In addition to suppliers who bring the supply of pipes, fuel and food, anchor-handling tugs are needed to lay the anchors . With these anchors, the pipelayer holds its exact position even in heavy seas and pulls itself forward with huge winches , depending on the pipelay speed.

Another possibility is to equip the ship with a dynamic positioning system (DPS). With the DPS, which are normally combined with freely rotating propeller pods, the computer keeps the ship in its position regardless of wind and current. The DPS also enables the pipeline's tensile load to be balanced. Today a DPS is mostly used with a Differential Global Positioning System (DGPS).

In order to avoid the formation of cracks in the pipe running off for laying, the requirements for positioning accuracy are high.

Pipelayer Castoro Sei (in the foreground) with the pipelayer and crane ship Saipem 7000 , both semi-submersible , in the port of Almería

Records from pipe layers

  • One of the largest and currently most efficient pipelayers in the world is the Solitaire , which is owned by the Swiss offshore service provider Allseas . The Solitaire was created by converting a bulk carrier . Solitaire, which works with the S-Lay method, holds the record for the greatest laying depth of 2775 m, in which it laid two pipelines measuring eight and ten inches. In addition, a 24-inch pipeline was laid at a depth of 2550 m. This ship also holds the record for the largest laying performance of nine kilometers in one day.
  • The record for laying a pipeline in J-Lay is held by the work ship DCV Balder from the Dutch company Heerema Marine Contractors (HMC). As part of the Mardi Gras project, she laid a pipeline in 2005 at a depth of 2200 m.

Laying the Nord Stream Pipeline through the Baltic Sea

In addition to Solitaire , the pipelayer Castoro Sei was also involved in laying the Nord Stream pipeline through the Baltic Sea. The anchor- handling tugs Maersk Tackler and Blizzard pulled the pipelayer to the starting point about 30 kilometers off the coast of Gotland and then laid the anchors, on which the pipelayer then pulled himself forward at the pace of the pipelay.

Literature and Sources

  • G. Clauss, E. Lehmann, C. Östergaard: Marine technical constructions. Springer Verlag, Berlin 1988.

Individual evidence

  1. Report on the Solitaire on the website of the TV station 3sat . www.3sat.de. Retrieved February 18, 2011.
  2. Allseas corporate website with historical data . www.allseas.com. Archived from the original on February 16, 2011. Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved February 18, 2011. @1@ 2Template: Webachiv / IABot / www.allseas.com
  3. Records on the Heerema Marine Contractors website . hmc.heerema.com. Archived from the original on November 19, 2008. Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved February 11, 2011. @1@ 2Template: Webachiv / IABot / hmc.heerema.com