Pipe-laying ship

Pipe layers are one type of service vessels lay pipes for the transportation of oil or gas on the sea floor.

Construction and Technology

Due to the necessary performance and the amount of material to be processed pipe fitters are usually relatively large floating units that are equipped with an elaborate infrastructure: Thus, on these ships welding equipment, equipment for material testing and for coating installed, and cranes to handle the pipe segments to can. In addition, helicopters are used to transport personnel and ensure the supply of urgent goods.

Laying technique

On the ship are the tubes that are usually made ​​of 40 feet ( about 12.2 meters) long segments are welded to the pipeline. Today, the installation is done, in a multi-stage process in which first two or more individual segments welded together to pieces from up to four individual segments with 48.8 m length ( so-called quadruple - joints or quad joints ) were manufactured. This pre-welded modules are then welded in the so-called Fire -Line to " endless " pipeline. You can also check the welds by non-destructive testing of materials and coating of welds with plastics is carried out in the Fire Line.

In modern installation methods today between the S-lay and J-lay, which basically differ in the laying sequence or in guiding the pipeline during laying of each other. While the S-lay method is mainly used for low and medium water depths, the J -Lay usually comes at great water depths are used. The depth record was achieved, however, the S-lay.

Positioning

In addition to utilities that bring the supply of pipes, fuel and meals, anchor handling tugs are required for installing the anchors. With these anchors the pipe layer also keeps in heavy seas its exact location and contracts depending on the pipe laying speed with huge winches forward.

Another possibility is the equipment of the ship with a system for dynamic positioning ( DPS ). With the DPS, which are usually combined with freely rotating propeller gondolas, the ship from the computer is maintained regardless of wind and current on his position. Also, the DPS allows compensation of the tensile load of the pipeline. Today, a DPS is usually used with a differential Global Positioning System ( DGPS).

Due to the risk of cracks in laying the pipeline, the demands on the positioning accuracy are correspondingly high.

Records of pipe fitters

  • The largest and currently most powerful and Pipe Fitter is the Solitaire, which is owned by the Swiss offshore service provider Allseas. The Solitaire was created by the conversion of a bulk carrier. The working with the S - lay method Solitaire holds the record for the largest burial depth of 2775 m, where they moved two pipelines with eight and ten inches. In addition, a 24-inch pipeline was laid at a depth of 2550 m. Also, the record for the biggest laying capacity with nine kilometers in a day is kept for this ship.
  • The record for laying a pipeline in the J -Lay holds the workboat DCV Balder the Dutch company Heerema Marine Contractors (HMC ). They moved as part of the Mardi Gras project, a pipeline in 2005 at a depth of 2200 m.

Laying of the Nord Stream gas pipeline through the Baltic Sea

The pipelaying Castoro Sei was involved in addition to the solitaire when laying the Nord Stream gas pipeline through the Baltic Sea. The anchor handling tug Maersk Tackler and Blizzard have the pipe layer to the starting point, about 30 kilometers off the coast of the island of Gotland, drawn, she then moved the anchor to which the pipe layer then moved forward in the pace of pipe laying.

Literature and sources

  • Clauss, G.; Lehmann, E.; Östergaard, C.: Marine Technical constructions. Springer Verlag, Berlin 1988.
Solitaire (ship)
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