Classifications

• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/02—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/02—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics
  • D07B1/025—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics comprising high modulus, or high tenacity, polymer filaments or fibres, e.g. liquid-crystal polymers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/02—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics
  • D07B1/04—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics with a core of fibres or filaments arranged parallel to the centre line
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/16—Ropes or cables with an enveloping sheathing or inlays of rubber or plastics
  • D07B1/162—Ropes or cables with an enveloping sheathing or inlays of rubber or plastics characterised by a plastic or rubber enveloping sheathing
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B5/00—Making ropes or cables from special materials or of particular form
  • D07B5/10—Making ropes or cables from special materials or of particular form from strands of non-circular cross-section
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/14—Ropes or cables with incorporated auxiliary elements, e.g. for marking, extending throughout the length of the rope or cable
  • D07B1/141—Ropes or cables with incorporated auxiliary elements, e.g. for marking, extending throughout the length of the rope or cable comprising liquid, pasty or powder agents, e.g. lubricants or anti-corrosive oils or greases
  • D07B1/142—Ropes or cables with incorporated auxiliary elements, e.g. for marking, extending throughout the length of the rope or cable comprising liquid, pasty or powder agents, e.g. lubricants or anti-corrosive oils or greases for ropes or rope components built-up from fibrous or filamentary material
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2016—Strands characterised by their cross-sectional shape
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2042—Strands characterised by a coating
  • D07B2201/2044—Strands characterised by a coating comprising polymers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2046—Strands comprising fillers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2075—Fillers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2075—Fillers
  • D07B2201/2076—Fillers having a lubricant function
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2083—Jackets or coverings
  • D07B2201/2087—Jackets or coverings being of the coated type
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2083—Jackets or coverings
  • D07B2201/2091—Jackets or coverings being movable relative to the internal structure
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/30—Inorganic materials
  • D07B2205/3007—Carbon
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2207/00—Rope or cable making machines
  • D07B2207/40—Machine components
  • D07B2207/404—Heat treating devices; Corresponding methods
  • D07B2207/4068—Heat treating devices; Corresponding methods for curing
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2501/00—Application field
  • D07B2501/20—Application field related to ropes or cables
  • D07B2501/2061—Ship moorings

Definitions

• the present invention relates to the field of anchors in the maritime environment, in particular offshore platforms, by means of cables.
• Tight line platforms are usually attached by means of hollow steel tubes anchored to the sea floor and fixed to the platform. These tubes work in traction to keep the platform in position. They are hollow to limit their weight and to present a certain buoyancy. When the depth of water under the platform is relatively large (typically beyond 1000 m), the pressure exerted on the lower parts of the tubes becomes significant, so that reinforcement of these tubes is necessary, which entails a significant additional cost and affects the buoyancy of the system.
• Some studies have considered replacing steel tubes with carbon fiber-based composite cables (see KS Kim et al. "Application of Composites in TLP Tethers", Proceedings of the 7th International Conference on Offshore Mechanics and Arctic Engineering, Houston, February 1988, Vol. 3, pages 1-7).
• JM Walton et al. describe a composite cable comprising pultruded rods grouped in a bundle with hexagonal geometry surrounded by a plastic sheath.
• a composite cable comprising pultruded rods grouped in a bundle with hexagonal geometry surrounded by a plastic sheath.
• An object of the present invention is to propose a new technique of composite cables which is well adapted to the constraints of offshore, and which can be applied to other industries.
• the invention thus proposes a method for producing a composite fastening cable, in particular for a maritime platform, comprising the following steps:
• sub-assemblies by assembling pultruded strands composed of tensile-resistant fibers embedded in a resin, and by coating the assembled strands in a protective plastic sheath; - wind the sub-assemblies on transport coils;
• the sub-assemblies are semi-finished products sized to allow their storage on reels of dimensions compatible with the means of land transport (a few meters). They can be wound on their transport coils by twisting them, typically at the rate of one revolution every ten meters approximately.
• the sub-assemblies can thus be transported to a facility located by the sea, where they are assembled and sheathed to form the cable.
• This assembly can be modulated in the sense that, according to the characteristics specific to each PLT anchor line, the required number of sub-assemblies can be assembled.
• Another advantageous modular nature of the cable relates to the means used to anchor it to the sea bottom and / or on the platform. It is thus possible to anchor fastening members at the ends of the individual sub-assemblies, either at the time of manufacture of the sub-assemblies, or at the time of their assembly. If the anchorage of one of these members fails when the cable is in service, only a sub-assembly will be affected by the rupture. The method thus provides a certain tolerance for defects.
• the cable sub-assemblies can be brought together in different groups, and it is each of these groups which receives a fixing member before the installation of the cable at sea. You can consider floating the cable and towing it to the platform site.
• the attachment cable can be wound on another transport reel of large dimensions allowing transport on cargo.
• the diameter of such a coil can be several tens of meters, the cable being twisted during its winding according to a twist which in general only creates elastic stresses in the materials, typically at the rate of one revolution every fifteen about meters.
• the sub-assembly constitutes a semi-finished product which can be used on many sites, which makes it possible to reduce its manufacturing cost.
• the fact of bringing the complete cable to the platform greatly simplifies the installation operations on the maritime site, which also contributes to making the technique economically attractive, especially for relatively great depths.
• Another advantage of constituting the cable into sub-assemblies is to ensure a low overall rigidity in bending, the sub-assemblies being able to slide along one another.
• the cable structure makes it possible to reduce micro-movements between the pultruded strands during fatigue stresses. These micro-movements only take place in the sub-assemblies whereas in the case of a cable made up only of pultruded strands, all these strands rub between them.
• the protective sheath of the sub-assembly provides double protection in the event of loss of tightness of the outer sheath of the cable.
• Another aspect of the present invention relates to a composite fastening cable, in particular for a maritime platform, comprising an outer sheath of plastic material and sub-assemblies arranged in a bundle contained in the outer sheath, each sub-assembly comprising, in a protective plastic sheath, a juxtaposition of pultruded strands composed of tensile-resistant fibers embedded in a resin.
• FIG. 1 is a perspective view showing the structure of a fastening cable according to the invention
• - Figure 2 is a perspective view detailing the structure of a sub- cable assembly
• - Figure 3 is a diagram of a cable assembly installation.
• the elementary strands, from which the composite cable 4 shown in FIG. 1 is made, are pultruded rods 5.
• These rods 5 are composed of unidirectional fibers embedded in a resin matrix.
• the unidirectional fibers are preferably made of carbon. They can be high resistance fibers (HR) or high modulus fibers (HM). Since the anchoring of the PLTs is mainly dimensioned by the stiffness of the lines, rods based on HM fibers are preferably used.
• the resin coating the locks of carbon fibers in the pultruded rods can be a thermosetting or thermoplastic polymer.
• the pultruded rods 5 are assembled in sub-assemblies 6.
• this assembly is of hexagonal geometry, and is made up of nineteen rods. The number nineteen seems to be a good compromise for making a cable according to the invention, but one could also consider hexagonal arrangements of seven or thirty-seven rods.
• This sheath, deposited by extrusion on the grouped rods, has for example a thickness of 2 mm. It provides mechanical protection for the sub-assembly during its handling.
• a reversible flexible substance 8 is injected in the intervals between the rods, and in the intervals between the rods 5 and the sheath 7.
• This substance 8 can for example be petroleum wax or any other flexible polymer. It mainly serves to block the rods 5 relative to each other to avoid undesirable displacements under the effect of the hydrostatic pressure at the bottom of the sea, and during the manipulations of the subassembly 6 and of the cable 4.
• the sub-assembly 6 is twisted with a pitch of ten meters, in order to ensure the storage and the transport of the sub-assemblies 6 on medium-sized coils (for example internal diameter of 2.50 m, external diameter of 5, 50 m and axial width of 2.00 m).
• This slight twist - rods standardize the forces due to the curvature of the sub-assembly on its coil. transport.
• the sub-assemblies 6 are used to form the cable 4, the stiffness of which is determined by the number of sub-assemblies chosen.
• the cable 4 has thirty-seven sub-assemblies 6 juxtaposed in a hexagonal arrangement.
• the assembly of the sub-assemblies is also surrounded by a HDPE sheath 9.
• the thickness of this sheath 9 (for example 15 mm) is provided to effectively protect the cable in a marine environment.
• the intervals between the sub-assemblies 6, and between the sub-assemblies 6 and the sheath 9, are filled with a viscous incompressible lubricant 10 which can for example be a petroleum wax.
• a viscous incompressible lubricant 10 which can for example be a petroleum wax.
• Such coils are used in shipping.
• the assembled sub-assemblies 6 are twisted with a pitch of the order of 15 m to facilitate winding.
• Figure 3 shows schematically a composite cable manufacturing workshop, installed in a factory located by the sea.
• the sub-assemblies 6 are unwound from their transport coils
• This orbital movement consists of a rotation along the axis of the coil 12 to unwind the sub-assembly, combined with a rotation along the axis of extraction of the sub-assembly to remove the twist.
• the subassemblies 6 pass through a first series of guide rollers 13 before reaching the device 14 which injects the lubricant 10.
• the assembly is then pressed into a second series of rollers 15, then supplied to an extruder 16 which deposits the sheath in HDPE 9.
• Downstream of the extruder 16 is a motor 17 which tows the cable 4, and a third series of guide rollers 18 preceding the support with orbital movement of the reel 19 for transporting the cable.
• This coil 19 pivots about its axis to wind the cable 4, and also includes a pivoting component transverse to its axis in order to twist the subassemblies 6 of the cable therebetween.
• the schematic diagram of the workshop for manufacturing the subassemblies 6 is very similar to that of FIG. 3 (except that the rods 5 are not unwound from coils with orbital movement). But of course, its dimensions are much smaller than those of the cable assembly workshop 4.
• This workshop for manufacturing sub-assemblies 6 can for example be installed in the pultrusion plant.
• the cable anchoring systems 4 on the platform and at the bottom of the sea can be partly mounted on the cable during its manufacture.
• the anchoring of these fixing members on the subassemblies can be carried out in a manner known per se by gluing.
• the fasteners on the side intended to be located at the bottom of the sea are designed to be simply fixed, for example by bolting, on anchor blocks made at the appropriate places.
• these members may include tension adjustment means, for example of the screw-nut type.

Landscapes

• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Ropes Or Cables (AREA)
• Laying Of Electric Cables Or Lines Outside (AREA)
• Moulding By Coating Moulds (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9541191

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (3)

Citations (2)

• 1999
  • 1999-01-25 FR FR9900784A patent/FR2788792B1/fr not_active Expired - Lifetime
• 2000
  • 2000-01-21 BR BRPI0007685-6A patent/BR0007685B1/pt not_active IP Right Cessation
  • 2000-01-21 GB GB0118132A patent/GB2363617B/en not_active Expired - Lifetime
  • 2000-01-21 WO PCT/FR2000/000139 patent/WO2000043587A1/fr active Application Filing
  • 2000-01-21 MX MXPA01007509A patent/MXPA01007509A/es active IP Right Grant
  • 2000-01-21 AU AU30582/00A patent/AU3058200A/en not_active Abandoned
• 2001
  • 2001-07-24 NO NO20013635A patent/NO20013635L/no not_active Application Discontinuation

Patent Citations (2)

Non-Patent Citations (1)

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