The present invention relates to a floating cable factory comprising a cable production vessel with a super structure, for production of for instance subsea umbillicals.

Background of the invention

Subsea umbillicals are designed for the transmission of power, fluids, electrical and optical control to offshore installations. Subsea production umbilicals include many different components to suit a mix of power and control functions needed offshore and subsea as thermoplastic hoses or steel tubes provide hydraulic valve control functions and low voltage cables are used for communications.

The power cable/conductor is made up of wires of metal and an insulation layer made of either EPR (ethylene propylene rubber) or XLPE (cross-linked

polyethylene). The power cables are twisted together into a helix with plastic hoses or steel tubes and fiber optics in a vertical or horizontal bundling machine. The process of twisting enables the composite bundles to be bent much tighter than if the function were straight, enabling the power cable or umbilical to be shipped and installed with greater ease.

A strength member can be added as a steel wire and as a layer of steel wires forming an armor on the outside of the bundle. Fill members as ropes or plastic material can be added to fill the internal gaps and petroleum gels can add water resistance. The outer coiled steel or aluminum layer provides mechanical protection, tensile strength and impact protection.

An outer sheath encases all the other layers. A sheath is frequently made from a continuously extruded thermoplastic material such as polyethylene, which has the physical strength and moisture resistance capabilities.

Most global production facilities, utilize horizontal lay up machines. Some few manufacturers utilize vertical machines, mainly so-called EZ production principle or non-helical. Disclosure of prior art

WO 2015/112007 A1 discloses a method for manufacturing a subsea pipeline and spooling said pipeline onto a reel or a carousel of a pipe-laying vessel at a spool base. The method comprises connecting pipes end-to-end at a pipeline assembly station to form a continuous pipeline stalk. The continuous pipeline stalk is spooled directly from the pipe assembly station onto a floating intermediate pipeline storage device that is adjacent the pipeline assembly station and the stalk is temporarily stored thereon. The pipeline stalk is later spooled from the floating intermediate temporary pipeline storage device onto the reel of the pipe-laying vessel. The floating intermediate pipeline storage device is a carousel pipeline storage device, which has an annular floating base that is assembled from multiple barges, which are interconnected in an annular array and having an above waterline carousel.

US 005813106 discloses a method and apparatus for manufacturing and laying out an umbilical, and EP 2085308 A2 discloses an apparatus with a floating container for a cable.

Objects of the present invention

The system for umbillicals and subsea cable production according to the invention utilizes known technology in a new and innovative configuration creating a new methodology and production technology for producing long umbillicals and subsea cables.

The utilization of floating turrets and a floating factory enables the production of much longer continuous length subsea cables than present global capabilities.

The benefit of the floating cable factory is significantly longer continuous process of cables without welding joints, significantly simplified logistics and processing and significantly cost reduction.

The floating factory can also be moved close to the marked.

It is also an object of the invention to provide a floating cable factory in where cable tanks easily can be driven in or out from a production tower. At least one object of the invention is to provide an alternative method for production of cables.

Summary of the invention

One or more of said objects are achieved with a floating cable factory, comprising:

- a cable production vessel,

- a super structure on said production vessel for receipt and combination of single core cables,

- several cable supply tanks with feeder turrets for feeding said single core cables to the super structure, said cable supply tanks are placed floating in or adjacent the production vessel,

- at least one main cable tank with a center turret, said main cable tank is placed floating in a slot in the production vessel and centrally below the super structure for receipt of a main cable wound in the super structure, and

- said superstructure comprises vertical turn wheels supporting the single core cables received from the feeder turrets in the cable supply tanks, and a rotational pull assembly pulling and winding the main cable.

The center turret can be placed rotational and floating in the main cable tank.

Similar, said feeder turrets can be placed rotational and floating in each cable supply tank.

One or more cable supply tanks can be placed floating in the slot in the production vessel.

Optionally, hoses or tubes for feeding of the single core cables can be extending from the feeder turret of each supply tank and up to the super structure.

Said superstructure can comprise a vertical turntable frame equipped with several vertical turn wheels supporting the single core cables received from the feeder turrets in the cable supply tanks.

Said superstructure may further comprise a collecting guide for receipt of the single core cables from the vertical turn wheels, and a distribution and turn restrictor wheel placed downstream of the collecting guide.

The rotational pull assembly in the superstructure is preferably placed downstream of the distribution and turn restrictor wheel. A rotational distribution guide can be placed above the floating main cable tank.

Said main cable tank can be driven in or out of the production vessel. Said cable supply tanks can be driven in or out of the production vessel, or be driven to or away from the production vessel.

Each cable supply tank can comprise a rotational feeder guide for guiding of the single core cable from the feeder turret.

The floating cable factory may further comprise a final product line assembly with one or more extruders, water cooling, gas super cooling, and pulling units to prepare a final assembled main cable, and a floating final product export tank for receipt of the final assembled main cable.

The final product export tank can comprise a rotational and floating turret for receipt of the final assembled main cable.

The main cable can be supplied from the main cable tank and to the final product line assembly.

The rotational pull assembly in the superstructure can comprise a pulling unit.

Description of the figures

Embodiments of the present invention will now be described, by way of example only, with reference to the following figures, wherein:

Figure 1 is a simplified cross sectional side view of the invention, along the line A-A in figure 2.

Figure 2 is a simplified top view of the invention.

Figure 3 is a simplified cross sectional side view of a second embodiment of the invention, along the line A-A in figure 4.

Figure 4 is a simplified top view of the second embodiment of the invention.

Description of preferred embodiments of the invention

A main cable tank 21 with a center turret 5 is placed floating in a slot 23 of a production vessel 6 with a production tower or super structure 18. The vessel 6 can be a ship, barge, or other floating installation. The wavy line in the drawings indicates water level. Required number of cable supply tanks 22 with feeder turrets 9 is placed floating in selected positions around the production vessel 6. The cable supply tanks 22 comprises single core cables, hoses or tubes 20 for production of for instance an umbilical. The cable supply tanks 22 are labeled A,B,C,D,E,F,G,H in figures 2 and 4. The cable supply tanks 22 comprises liquid, such as for instance water, and the feeder turret 9 is placed floating and rotatable in the liquid.

Hoses or tubes 10 for feeding of the single core cables 20 can optionally extend from the feeder turret 9 of each supply tank 22 and up to the super structure 18.

Individual single core cables, hoses or tubes 20, hereinafter called single core cables, are pulled out of the rotational feeder turrets 9 and over vertical turn wheels 1 in the super structure 18. The single core cables 20 are thereafter led down through a collecting guide 2 with a distribution and turn restrictor wheel 3, and through a rotating pull assembly 4 with a pulling unit 17, such as a caterpillar. From the rotating pull assembly 4 the wounded main cable 19 is led through a rotational distribution guide 8 and into the rotating center turret 5 in the main cable tank 21.

Hence, the distribution and turn restrictor wheel 3 is placed downstream of the collecting guide 2, and said rotational pull assembly 4 in the superstructure 18 is placed downstream of the distribution and turn restrictor wheel 3. Downstream being in the pull direction of the cable.

The main cable tank 21 comprises liquid, such as for instance water, and the center turret 5 is placed floating and rotatable in the liquid.

The vertical turn wheels 1 , the rotational pull assembly 4, the rotational center turret 5, the rotational feeder turret 9, and rotational feeder guides 11 are electronically controlled by a unique control system where all units automatically adjust speed, pull and rotation. Each and every unit is tuned and can adjust itself automatically.

The winding of the single core cables 20 are preferable done in a manner known to the skilled person, and the method is therefore not elaborated in detail.

The rotational center turret 5 is placed floating in the main cable tank 21 , and can be turning clockwise. The rotational feeder turret 9 can likewise be placed floating in each cable supply tank 22, and can be turning anti-clockwise. The rotational center turret 5 and the rotational feeder turret 9 may of course turn in opposite directions.

Each cable supply tank 22 can further comprise a rotational feeder guide 11 for guiding of the single core cable 20 out from the feeder turret 9.

The main cable tank 21 can be driven in or out of the production vessel 6. Said cable supply tanks 22 can similar be driven in or out of the production vessel 6, and be driven to or away from the production vessel 6.

The floating cable factory can also comprise a final product line assembly, as shown in figures 3 and 4. A first guide arm 14 guides the main cable 19 out of the main cable tank 21. It is possible that the main cable 19 can be led from the super structure directly to the final product line assembly.

Several pulling units 17, such as caterpillars, can be used to pull the main cable 19 along the final product line. The final product line assembly further comprises several units, such as extruders 12, gas super cooling 16 and water cooling 15, or other equipment, to prepare and coat the final main cable 19. The final assembly of the main cable 19 is preferable done in a manner known to the skilled person, and it is therefore not elaborated in detail.

After the preparing and finalizing of the main cable 19, the main cable 19 is fed by a second guide arm 14 to a turret 13 in a final product export tank 24. The final product export tank 24 is floating next to the production vessel 6. The turret 13 can be placed rotational and floating in the final product export tank 24, similar to the feeder turret 9 and center turret 5.

After the bundling is complete and the main tank 21 with the center turret 5 is filled with the bundled cables/umbilical 19, the bundled cables 19 will be pulled out of the center turret 5 assisted by the first guiding arm 14 and into the extruderline for installing the outer sheet and finally guided by the second guiding arm 14 into the turret 13 of the floating export tank 24.

The floating export tank 24 can for instance keep more than 4000 ton of final product (cable/umbilical). This tank 24 can be floated into special modified transport- or installation-ships. The main cable 19 can as mentioned be an umbilical. An umbilical is a thick, complex and normally reinforced cable wound together of steel pipes and several thinner cables for power, fiber, communication, hydraulics, chemistry, and/or other cables, for surveillance and control of subsea wells. The single cables 20 can thus be any of the latter.