GB2101798A - Electric cable - Google Patents
Electric cable Download PDFInfo
- Publication number
- GB2101798A GB2101798A GB08211728A GB8211728A GB2101798A GB 2101798 A GB2101798 A GB 2101798A GB 08211728 A GB08211728 A GB 08211728A GB 8211728 A GB8211728 A GB 8211728A GB 2101798 A GB2101798 A GB 2101798A
- Authority
- GB
- United Kingdom
- Prior art keywords
- cable
- layer
- electric power
- power cable
- core electric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000010410 layer Substances 0.000 claims abstract description 37
- -1 polypropylene Polymers 0.000 claims abstract description 7
- 239000011241 protective layer Substances 0.000 claims abstract description 7
- 239000004760 aramid Substances 0.000 claims abstract description 4
- 229920003235 aromatic polyamide Polymers 0.000 claims abstract description 4
- 239000013307 optical fiber Substances 0.000 claims abstract 2
- 239000004020 conductor Substances 0.000 claims description 9
- 229920003023 plastic Polymers 0.000 claims description 7
- 239000004033 plastic Substances 0.000 claims description 7
- 229920000573 polyethylene Polymers 0.000 claims description 6
- 239000004698 Polyethylene Substances 0.000 claims description 5
- 238000010276 construction Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 229920001971 elastomer Polymers 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 2
- 230000011664 signaling Effects 0.000 claims 3
- 229910000906 Bronze Inorganic materials 0.000 abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 4
- 239000010974 bronze Substances 0.000 abstract description 3
- 239000004743 Polypropylene Substances 0.000 abstract description 2
- 229920001155 polypropylene Polymers 0.000 abstract description 2
- 229920004933 Terylene® Polymers 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 229920003020 cross-linked polyethylene Polymers 0.000 description 3
- 239000004703 cross-linked polyethylene Substances 0.000 description 3
- 239000005020 polyethylene terephthalate Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229920000271 Kevlar® Polymers 0.000 description 2
- 229920005549 butyl rubber Polymers 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 239000004761 kevlar Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B9/00—Power cables
- H01B9/005—Power cables including optical transmission elements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
- G02B6/4401—Optical cables
- G02B6/4415—Cables for special applications
- G02B6/4416—Heterogeneous cables
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/18—Protection against damage caused by wear, mechanical force or pressure; Sheaths; Armouring
- H01B7/182—Protection against damage caused by wear, mechanical force or pressure; Sheaths; Armouring comprising synthetic filaments
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B9/00—Power cables
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Insulated Conductors (AREA)
Abstract
A torque-balanced multi-core electric cable suitable for suspending vertically or in a catenary curve in a length of at least 1,000m comprises a flexible tensile member 1, cores 2 laid up in at least one layer around the tensile member and a protective layer comprising a binding layer 3 of helically wound tin- bronze tape and a serving layer 4 of helically lapped polypropylene tape. The tensile member 1 comprises aromatic polyamide filaments 6 of high tensile strength so arranged that each filament lies substantially parallel to the axis of the cable. The cable may incorporate an optical fibre. Where the cable is intended for use under water, preferably it has no overall water proof sheath but each core includes its own water-impermeable wall. The central tensile member 1 takes the tensile load and, by so doing, resists any tendency for the cable to twist and become tangled as a result of any inherent torque in the cable. <IMAGE>
Description
SPECIFICATION
An improved electric cable
This invention relates to a multi-core electric power cables and, more particularly, to multi-core electric power cables of the kind that, over at least a part of their lengths, can be suspended undertheir own weight so that they lie substantially vertically or in a catenary curve with negligible risk that they will twist and become tangled as a result of inherent torque in the cables arising from their construction. Multi-core electric power cables of this kind will, for convenience, hereinafter be referred to as "torquebalanced" cables.
One known form of torque-balanced multi-core electric power cable has armouring comprising two layers of stranded steel wires, the directions of lay of the two layers being of opposite hand and the length of lay of the outer-layer having regard to the length of lay of the inner layer being such that the torque imparted to the cable by the laid-up cores and one layer of armouring is substantially compensated by the torque imparted to the cable by the other layer of armouring, the cable thereby being substantially torque-balanced.Whilst this known form or torque- balanced cable is generally suitable in cases where the length of cable to be suspended under its own weight is not great, e.g. does not exceed 300m, it is not suitable where the length of cable to be suspended under its own weight greatly exceeds this figure and, for example, is in the region of 600m to 1 200m, which may be the case where the cable is to feed an oil or gas production facility on the seabed, because of the excessive weight of the suspended length of cable.
It is an object of the present invention to provide an improved torque-balanced multi-core electric power cable which is suitable for suspending substantially vertically or in a catenary curve under its own weight in a length of at least 1000m.
According to the invention, the improved multicore electric power cable comprises a central flexible tensile member, a plurality of cores laid up in at least one layer around the tensile member and, overlying the assembly, at least one overall outer protective layer, the central tensile member comprising a multiplicity of non-metallic filaments of high tensile strength so arranged that each filament lies substantially parallel to the axis of the cable.
Preferably, the multiplicity of non-metallic filaments is enclosed within a sheath of rubber or plastics material and where, as is preferred, the cores are of substantially the same diameter as one another, the radial thickness of the sheath surrounding the multiplicity of non-metallic filaments is such that the overall diameter of the central tensile member is substantially the same as the diameter of each core.
The multiplicity of non-metallic filaments of high tensile strength are preferably filaments of an aromatic polyamide generally sold under the trade mark "Kevlar". Each filament is preferably of substantially circular cross-section and has a diameter of about 1.2 x 10-2 mm. The sheath surrounding the multiplicity of Kevlarfilaments is preferably made of polyethylene but, in some circumstances, it may be of any other suitable plastics material.
The overall outer protective layer or layers of the cable preferably includes at least one layer of helically wound tape, e.g. a tape of tin-bronze alloy, which binds the layer or layers of cores to the central tensile member. An overall sheath of metal or metal alloy or of rubber or plastics material may overlie the binding layer of layers but, where the cable is intended for use underwater and at depths exceeding 300m, preferably each core is of such a construction that it includes a water-impermeable wall, and the cable has no overall waterproof sheath; in this case, preferably the layer or layers of helically wound tin-bronze tape is or are surrounded by at least one layer of serving, e.g. helically wound polpropylene tape.In this construction of cable, when the cable is installed under water, water will penetrate into the spaces between the cores and between the cores and the central tensile member but will not penetrate into any one of the cores.
The multi-core electric power cable of the present invention may also incorporate pilot cores and/or signailing conductors, which conductors may be either electrical conductors or optical fibres.
When the cable is suspended under its own weight substantially vertically or in a catenary curve either dry or underwater, the multiplicity of substantially straight non-metallic filaments consituting the central tensile member of the cable take substantially all the tensile load to which the cable is subjected and, by so doing, resist any tendency for the cable to twist and become tangled as a result of any inherent torque in the cable.
A preferred 11 kv multi-core electric power cable which may be suspended underwater under its own weight to depths of at least 1000m will now be described, by way of example, with reference to the accompanying diagrammatic drawing which shows a transverse cross-sectional view of the cable.
Referring to the drawing, the cable comprises a central flexible tensile member 1, six cores 2 laid helically around the central tensile member and, surrounding the cores, a binding layer 3 of helically wound tape of tin-bronze, the direction of lay of the tape being opposite to that of the helically laid cores, and a serving layer 4 of helically lapped tape of polypropylene, the direction of lay of the serving layer being opposite to that of the binding layer.
The central tensile number 1 comprises a multiplicity of filaments 6 of Kevlar, which filaments all lie substantially parallel to the axis of the cable and, surrounding the multiplicity of filaments, a sheath 7 of polyethylene.
The six cores 2 are arranged two cores per phase and each core is of a construction as described in the specification of our co-pending Patent Application
No. 82/ filed on the same day as the present application. Each core 2 comprises a flexible stranded conductor 11; a conductor screen 12 comprising a layer of semi-conducting tape and an extruded layer of semi-conducting cross-linked polyethylene; a dielectric wall 13 comprising an extruded layer of cross-linked polyethylene; a dielectric screen 14 comprising an extruded layer of semi-conducting cross-linked polyethylene; a cushioning layer 15 of non-vulcanised butyl rubber; a water-impermeable barrier comprising a longitudinally applied transversely folded copper tape 17 having on its inner surface a coating 16 of polyester which is bonded to the cushioning layer 15 and having on its outer surface a coating 18 of polyethylene; a plastics coated terylene filament 19 helically wound around the polythene-coated copper tape 17 under such tension as to form in the water-impermeable barrier a helical corrugation, the helical trough on the inner surface of the barrier being filled with non-vulcanised butyl rubber; and, overlying and bonded to the polyethylene coating 18 and to the plastics coated terylene filament 19, an extruded overall sheath 20 of high density polyethylene.
The cable illustrated in the drawing can be suspended underwater substantially vertically or in a catenary curve under its own weight to a depth of at least 1000m with negligible risk of twisting or tangling of the cable occurring because the central tensile member 1 takes substantially all the tensile load to which the cable will be subjected.
Terylene is a registered trade mark.
Claims (10)
1. A multi-core electric power cable comprising a central flexible tensile member, a plurality of cores laid up in at least one layer around the tensile member and, overlying the assembly, at least one overall outer protective layer, the central tensile member comprising a multiplicity of non-metallic filaments of high tensile strength so arranged that each filament lies substantially parallel to the axis of the cable.
2. A multi-core electric power cable as claimed in
Claim 1, wherein the multiplicity of non-metallic filaments is enclosed within a sheath of rubber or plastics material.
3. A multi-core electric power cable as claimed in
Claim 2, wherein the cores are of substantially the same diameter as one another and the radial thickness of the sheath surrounding the multiplicity of non-metallic filaments is such that the overall diameter of the central tensile member is substantially the same as the diameter of each core.
4. A multi-core electric power cable as claimed in any one of the preceding Claims, wherein the multiplicity of non-metallic filaments of high tensile strength are filaments of an aromatic polyamide.
5. A mutli-core electric power cable as claimed in
Claim 4, wherein the multiplicity of filaments of aromatic polyamide is enclosed within a sheath of polyethylene.
6. A multi-core electric power cable as claimed in any one of the preceding Claims, wherein the overall outer protective layer or layers of the cable includes at least one layer of helically wound tape which binds the layer or layers of cores to the central tensile member.
7. A multi-core electric power cable as claimed in
Claim 6, wherein an overall sheath of metal or metal alloy or of rubber or plastics material overlies the binding layer or layers.
8. A multi-core electric power cable as claimed in
Claim 6, wherein each core is of such a construction that it includes a water-impermeable wall and the cable has no overall waterproof sheath.
9. A multi-core electric power cable as claimed in
Claim 8, wherein the layer or layers of helically wound tape is or are surrounded by at least one layer of serving.
10. A multi-core electric power cable as claimed in any one of the preceding Claims, wherein the cable incorporates at least one pilot core and/or signalling conductor, the signalling conductor or at least one of the signalling conductors being an electrical conductor or an optical fibre.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08211728A GB2101798B (en) | 1981-04-23 | 1982-04-22 | Electric cable |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8112592 | 1981-04-23 | ||
| GB08211728A GB2101798B (en) | 1981-04-23 | 1982-04-22 | Electric cable |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2101798A true GB2101798A (en) | 1983-01-19 |
| GB2101798B GB2101798B (en) | 1985-03-27 |
Family
ID=26279225
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08211728A Expired GB2101798B (en) | 1981-04-23 | 1982-04-22 | Electric cable |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2101798B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2144878A (en) * | 1983-08-05 | 1985-03-13 | Bicc Plc | Optical cables |
| GB2185334A (en) * | 1986-01-07 | 1987-07-15 | Bicc Plc | Elongate flexible core for optical cable |
| US4966706A (en) * | 1987-08-05 | 1990-10-30 | Peroxid-Chemie Gmbh | Process for treatment of clarification sludge |
| CN111292883A (en) * | 2020-02-17 | 2020-06-16 | 中天科技海缆有限公司 | Light-duty nonmetal armor submarine cable |
| NO20190358A1 (en) * | 2019-03-18 | 2020-09-21 | Blue Sea Norway As | Power cable, method for production and use thereof |
-
1982
- 1982-04-22 GB GB08211728A patent/GB2101798B/en not_active Expired
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2144878A (en) * | 1983-08-05 | 1985-03-13 | Bicc Plc | Optical cables |
| GB2185334A (en) * | 1986-01-07 | 1987-07-15 | Bicc Plc | Elongate flexible core for optical cable |
| US4793685A (en) * | 1986-01-07 | 1988-12-27 | Bicc Plc | Optical cable with nonmetallic reinforcing elements |
| GB2185334B (en) * | 1986-01-07 | 1989-10-25 | Bicc Plc | Elongate flexible core for optical cable |
| US4966706A (en) * | 1987-08-05 | 1990-10-30 | Peroxid-Chemie Gmbh | Process for treatment of clarification sludge |
| NO20190358A1 (en) * | 2019-03-18 | 2020-09-21 | Blue Sea Norway As | Power cable, method for production and use thereof |
| NO345275B1 (en) * | 2019-03-18 | 2020-11-23 | Blue Sea Norway As | Power cable, method for production and use thereof |
| US11562833B2 (en) | 2019-03-18 | 2023-01-24 | Blue Sea Norway As | Power cable, method for production and use thereof |
| CN111292883A (en) * | 2020-02-17 | 2020-06-16 | 中天科技海缆有限公司 | Light-duty nonmetal armor submarine cable |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2101798B (en) | 1985-03-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |