NZ245430A - Composite overhead electrical-optical conductor with ribbons of optical fibres - Google Patents
Composite overhead electrical-optical conductor with ribbons of optical fibresInfo
- Publication number
- NZ245430A NZ245430A NZ245430A NZ24543092A NZ245430A NZ 245430 A NZ245430 A NZ 245430A NZ 245430 A NZ245430 A NZ 245430A NZ 24543092 A NZ24543092 A NZ 24543092A NZ 245430 A NZ245430 A NZ 245430A
- Authority
- NZ
- New Zealand
- Prior art keywords
- optical
- optical fibre
- stack
- conductor
- overhead electric
- Prior art date
Links
- 230000003287 optical effect Effects 0.000 title claims description 85
- 239000004020 conductor Substances 0.000 title claims description 60
- 239000002131 composite material Substances 0.000 title claims description 50
- 239000013307 optical fiber Substances 0.000 claims description 57
- 229910052751 metal Inorganic materials 0.000 claims description 15
- 239000002184 metal Substances 0.000 claims description 15
- 239000011347 resin Substances 0.000 claims description 13
- 229920005989 resin Polymers 0.000 claims description 13
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 8
- 239000004925 Acrylic resin Substances 0.000 claims description 6
- 229920000178 Acrylic resin Polymers 0.000 claims description 5
- 239000011248 coating agent Substances 0.000 claims description 4
- 238000000576 coating method Methods 0.000 claims description 4
- 239000011810 insulating material Substances 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 4
- 229920003023 plastic Polymers 0.000 claims description 4
- 229920003020 cross-linked polyethylene Polymers 0.000 claims description 3
- 239000004703 cross-linked polyethylene Substances 0.000 claims description 3
- 239000004811 fluoropolymer Substances 0.000 claims description 2
- 229920002313 fluoropolymer Polymers 0.000 claims description 2
- 239000005304 optical glass Substances 0.000 claims description 2
- 229920002379 silicone rubber Polymers 0.000 claims description 2
- 241001125671 Eretmochelys imbricata Species 0.000 claims 1
- 230000005540 biological transmission Effects 0.000 description 8
- 239000004411 aluminium Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
Classifications
-
- 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
-
- 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
- G02B6/4403—Optical cables with ribbon structure
-
- 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
- G02B6/441—Optical cables built up from sub-bundles
- G02B6/4411—Matrix structure
-
- 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
- G02B6/4422—Heterogeneous cables of the overhead type
-
- 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
- G02B6/4429—Means specially adapted for strengthening or protecting the cables
- G02B6/443—Protective covering
-
- 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
- G02B6/4429—Means specially adapted for strengthening or protecting the cables
- G02B6/44384—Means specially adapted for strengthening or protecting the cables the means comprising water blocking or hydrophobic materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
- H01B5/08—Several wires or the like stranded in the form of a rope
- H01B5/10—Several wires or the like stranded in the form of a rope stranded around a space, insulating material, or dissimilar conducting material
- H01B5/108—Several wires or the like stranded in the form of a rope stranded around a space, insulating material, or dissimilar conducting material stranded around communication or control conductors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Communication Cables (AREA)
Description
245430 Priority Date (s): I). ) 2:\ .?>.!.
Complete Specification Filed:. J.Q.U?.!.*:!.? Class: (6) Publication Date: 2 5.MAR1995 P.O. Journal No: Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION AN IMPROVED COMPOSITE OVERHEAD ELECTRIC AND OPTICAL CONDUCTOR WE, BICC PUBLIC LIMITED COMPANY, a British company of Devonshire House, Mayfair Place, London, ENGLAND W1X 5FH hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: (followed by page la) 2 4 5 4 3 AH IMPROVED COMPOSITE OVERHEAD BLECTRIC AND OPTICAL CONDUCTOR This invention relates to overhead electric conductors of the kind which comprise one or more than one layer of helically wound elongate elements of electrically conductive metal or metal alloy and which are adapted to be freely suspended in long lengths from towers, pylons or other upstanding supports mutually spaced along the route of an overhead electric transmission or distribution system.
The invention is particularly concerned with overhead electric conductors of this kind which include at least one flexible optical guide consisting of or comprising at least one optical fibre for transmission of the ultra-violet, visible and infra-red regions of the electro-magnetic spectrum, which regions, for convenience, will hereinafter all be included in the generic term "light". One composite overhead electric optical conductor of this kind is the subject of our British Patent No: 1598438.
It has become the general practice to employ a composite overhead electric and optical conductor of the aforesaid kind as an earth conductor of an overhead electric transmission or distribution system and, because a composite overhead electric and optical conductor of this kind may be manufactured to have the same or approximately the same properties of sag and tension as those of conventional overhead earth (followed by page 2) 24 5 4 3 2. conductors of substantially the same overall diameter, it can be used to replace a conventional overhead earth conductor of an existing overhead electric transmission or distribution system thereby to provide a relatively inexpensive communication link between stations, substations and other locations along the route of the system and/or an optical communication system between populated areas between which the overhead electric transmission or distribution system extends.
With the rapid growth of communication services required, it is recognised that a composite overhead electric and optical conductor of the aforesaid kind of necessity will have to incorporate a greater number of optical fibres for the transmission of light signals than has hitherto been provided. Whilst increasing the number of optical fibres incorporated in an overhead electric conductor is not in itself a problem, it is desirable that an increase in optical fibre count of a composite overhead electric and optical conductor is achieved without effecting a substantial increase in the overall diameter, and hence weight, of the conductor.
This is especially important where a composite overhead electric and optical conductor having a high optical fibre count is to be used to replace an overhead earth conductor of an existing overhead transmission or distribution system if the substantial expense of upgrading the towers, pylons or other upstanding 245430 3. supports of the system to accommodate a larger and heavier earth conductor is to be avoided.
It is an object of the present invention to provide an improved composite overhead electric and optical conductor which can have a greater number of optical fibres than and substantially the same overall diameter as composite overhead electric and optical conductors hitherto proposed and used.
According to the invention, the improved composite overhead electric and optical conductor comprises a circumferentially rigid central core of metal or metal alloy having throughout its length a bore in which a flexible optical guide is substantially tightly disposed and, surrounding the central metal core, at least one layer of helically wound elongate elements of electrically conductive metal or metal alloy, which flexible optical guide comprises a plurality of optical fibre ribbons arranged face-to-face to form a stack, each optical fibre ribbon comprising at least two optical fibres arranged side-by-side with their axes lying in a common plane and wholly encapsulatsd in a cured resin, an overall sheath of plastics material surrounding the stack of optical fibre ribbons and, filling the interstices between the stack of optical fibre ribbons and the sheath, a cured resin.
Preferably, to ensure that the improved composite overhead electric and optical conductor is capable of 4. withstanding temperatures of up to approximately 250°C with negligible risk of degradation of the optical fibres of the optical fibre ribbons due to heat exposure, the cured resin within which the stack of optical fibre ribbons is wholly encapsulated is a photo-cured acrylate resin and the overall sheath is of cross-linked polyethylene. Where the improved composite conductor is required to withstand temperatures substantially higher than 250°C, e.g. at least 300°C, preferably the overall sheath is made of a high temperature resistant thermoplastics material, e.g. a fluoropolymer; preferably, in these circumstances a layer of thermal insulating material underlies and/or overlies the overall plastics sheath to limit further risk of degradation of the optical fibres of the optical fibre ribbons due to heat exposure. Suitable thermal insulating materials include silicone elastomers.
Each optical fibre ribbon of the stack may comprise the same number of optical fibres as the other optical fibre ribbon or each of the other optical fibre ribbons of the stack but, preferably, with a view to ensuring that the imaginary cylinder of circular cross-section circumscribing the stack has as small a diameter as possible, the outermost optical fibre ribbons of a stack comprising three or more optical fibre ribbons each comprises fewer optical fibres than the or each optical fibre ribbon sandwiched therebetween. For . example, a flexible optical guide of the improved composite conductor of the present invention comprising twelve optical fibres has a stack comprising two optical fibre ribbons, each comprising four optical fibres, sandwiched between two optical fibre ribbons each comprising two optical fibres.
Each optical fibre of each optical fibre ribbon of the stack preferably has a coating of a colour readily distinguishable from the colour of the coating of the or each other of the optical fibres of the optical fibre ribbon.
Preferably, each optical fibre of each optical fibre ribbon of the improved composite overhead electric and optical conductor has been proof-tested to ensure that it is capable of withstanding any tensile force to which it is likely to be subjected whilst the composite conductor is in service and, in general, optical fibres currently available from Optical Fibres, Deeside, Clwyd are wholly suitable for use in the improved composite conductor, but where the improved composite conductor is to be used in an overhead electric transmission or distribution system where it is likely to be subjected to exceptionally severe conditions whilst it is in service, specially manufactured strain-resistant optical fibres may be employed.
With a view to reducing risk of buckling of the flexible optical guide of the improved composite 2 4 5 4 6. conductor before the flexible optical guide is tightly disposed in the bore of the circumferentially rigid tubular central core, the flexible optical guide may incorporate two or more elongate elements of tensile resistant material, each preferably a pultruded elongate element of resin bonded fibres of non-optical glass or other non-metallic tensile resistant material. Such tensile resistant elongate elements may be wholly encapsulated in the cured resin in which the stack of optical fibre ribbons is encapsulated and/or at least one optical fibre of each of two or more of the optical fibre ribbons of the stack may be replaced by a tensile resistant elongate element. In all cases, the tensile resistant elongate elements will be evenly distributed within the flexible optical guide of the improved composite conductor.
The circumferentially rigid central tubular metal core preferably is a tube of metal or metal alley, which tube may be formed by extrusion or may have a welded seam, but in some circumstances it may be formed from an extrudate of approximately C-shaped cross-section, the limbs of the extrudate being closed to form a seamed tube.
By way of example, a flexible optical guide of the improved composite conductor having a stack of four optical fibre ribbons arranged face-to-face, the intermediate optical fibre ribbons each comprising four 7. optical fibres and the end optical fibre ribbons each comprising two optical fibres, has an overall diameter which is less than half that of a comparable flexible optical guide of composite conductors hitherto proposed and used, as a consequence of which the improved composite conductor has an overall diameter which can be substantially less than that of most known comparable composite conductors.
Furthermore, an improved composite conductor having an exceptionally high optical fibre count, forty-eight optical fibres, can comprise two or more flexible optical guides of the improved composite conductor hereinbefore described helically laid up together and substantially tightly disposed in the bore of a circumferentially rigid tubular central core of metal or metal alloy, the interstices between the assembled optical guides being filled with a water-impermeable medium or accommodating water-swellable elements throughout the length of the composite conductor. For example, an improved composite conductor of the present invention comprising four flexible optical guides helically laid up together, each having a stack of optical fibre ribbons totalling twelve optical fibres, will have an overall diameter no greater than that of composite overhead conductors hitherto proposed and used having only twenty-four optical fibres. 24 54 3 0 Q • The invention is further illustrated by a description, by way of example, of a preferred composite overhead electric and optical conductor with reference to the accompanying drawing which shows a transverse cross-sectional view of the conductor, drawn on an enlarged scale.
Referring to the drawing, the preferred composite overhead electric and optical conductor comprises a circumferentially rigid central aluminium tube 2 which has tightly disposed in its bore throughout its length a flexible optical guide 1 and, surrounding the aluminium tube, a layer 3 of helically wound steel wires 4. The flexible optical guide 1 comprises a stack 5 of four optical fibre ribbons 6, 7 arranged face-to-face and surrounded by an overall sheath 10 of cross-linked polyethylene. The stack 5 comprises two optical fibre ribbons 6, each consisting of four optical fibres 8 arranged side-by-side with their axes lying in a common plane and wholly encapsulated in photo-cured acrylic resin 9, sandwiched between two optical fibre ribbons 7, each consisting of two optical fibres 8 arranged side-by-side with their axes lying in a common plane and wholly encapsulated in photo-cured acrylic resin 9. The interstices between the stack 5 of optical fibre ribbons 6, 7 and the overall sheath 10 are filled with photo-cured acrylic resin 11.
The preferred composite overhead electric and optical conductor illustrated in the accompanying drawing and incorporating twelve optical fibres is of substantially the same overall diameter as composite overhead electric and optical conductors hitherto proposed and used incorporating only a few optical fibres.
Claims (15)
1. A composite overhead electric and optical conductor comprising a circumferentially rigid central core of metal or metal alloy having throughout its length a bore in which a flexible optical guide is substantially tightly disposed and, surrounding the central metal core, at least one layer of helically wound elongate elements of electrically conductive metal or metal alloy, wherein the flexible optical guide comprises a plurality of optical fibre ribbons arranged face-to-face to form a stack, each optical fibre ribbon comprising at least two optical fibres arranged side-by-side with their axes lying in a common plane and wholly encapsulated in a cured resin, an overall sheath of plastics material surrounding the stack of optical fibre ribbons and, filling the interstices between the stack of optical fibre ribbons and the sheath, a cured resin.
2. A composite overhead electric and optical conductor as claimed in Claim 1, wharein the stack comprises three or more optical fibre ribbons and wherein the outermost optical fibre ribbons of the stack each comprises fewer optical fibres than the or each optical fibre ribbon sandwiched therebetween.
3. A composite overhead electric and optical conductor as claimed in Claim 2, wherein the stack comprises two optical fibre ribbons, each comprising four optical fibres, sandwiched between two optical fibre ribbons each comprising two optical fibres. 11.
4. A composite overhead electric and optical conductor as claimed in any one of the preceding Claims wherein the flexible optical guide incorporates two or more elongate elements of tensile resistant material evenly distributed within the guide.
5. A composite overhead electric and optical conductor as claimed in Claim 4, wherein the tensile resistant elongate elements are wholly encapsulated in the cured resin in which the stack of optical fibre ribbons is encapsulated and/or at least one optical fibre of each of two or more of the optical fibre ribbons of the stack is replaced by a tensile resistant elongate element.
6. A composite overhead electric and optical conductor as claimed in Claims 4 or 5, wherein each tensile resistant elongate element is a pultruded elongate element of resin bonded fibres of non-optical glass or other non-metallic tensile resistant material.
7. A composite overhead electric and optical conductor as claimed in any one of the preceding Claims wherein the cured resin within which the stack of optical fibre ribbons is wholly encapsulated is a photo cured acrylic resin and the overall sheath is of cross-linked polyethylene.
8. A composite overhead electric and optical conductor as claimed in any one of Claims 1 to 6, wherein the cured resin within which the stack of 12. optical fibre ribbons is wholly encapsulated is a photo-cured acrylic resin and the overall sheath is of a fluoropolymer.
9. A composite overhead electric and optical conductor as claimed in Claim 8, wherein a layer of thermal insulating material underlies and/or overlies the overall sheath.
10. A composite overhead electric and optical conductor as claimed in Claim 9, wherein the thermal insulating material of the or each said layer is a silicone elastomer.
11. A composite overhead electric and optical conductor as claimed in any one of the preceding Claims, wherein each optical fibre of each optical fibre ribbon of the stack has a coating of a colour readily distinguishable from the colour of the coating of the or each other of the optical fibres of the optical fibre ribbon.
12. A composite overhead electric and optical conductor as claimed in any one of the preceding Claims, wherein each optical fibre has been proof-tested.
13. A composite overhead electric and optical conductor as claimed in any one of the preceding Claims, wherein the circumferentially rigid central core of metal or metal alloy is an extruded tube or is a tube having a welded seam. 245430 13.
14. A composite overhead electric and optical conductor comprising a circumferentially rigid central core of metal or metal alloy having throughout its length a bore in which two or more flexible optical guides are helically laid up together and substantially tightly disposed and, surrounding the central metal core, at least one layer of helically wound elongate elements of electrically conductive metal or metal alloy, wherein each flexible optical guide comprises a plurality of optical fibre ribbons arranged face-to-face to form a stack, each optical fibre ribbon comprising at least two optical fibres arranged side-by-side with their axes lying in a common plane and wholly encapsulated in a cured resin, an overall sheath of plastics material surrounding the stack of optical fibre ribbons and, filling the interstices between the stack of optical fibre ribbons and the sheath, a cured resin, and wherein the interstices between the assembled optical guides are filled with a water-impermeable medium or accommodate water-swellable elements throughout the length of the composite conductor.
15. A composite overhead electric and optical conductor substantially as hereinbefore described with reference to and as shown in the accompanying drawing. BICC PUBLIC LIMITED COMPANY By Their Attorneys BALDWIN SON & CAREY
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB919126232A GB9126232D0 (en) | 1991-12-11 | 1991-12-11 | An improved composite overhead electric and optical conductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NZ245430A true NZ245430A (en) | 1996-03-26 |
Family
ID=10706016
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NZ245430A NZ245430A (en) | 1991-12-11 | 1992-12-10 | Composite overhead electrical-optical conductor with ribbons of optical fibres |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU670552B2 (en) |
| GB (2) | GB9126232D0 (en) |
| NZ (1) | NZ245430A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6621966B2 (en) * | 1999-03-31 | 2003-09-16 | Corning Cable Systems Llc | Fiber optic cable with profiled group of optical fibers |
| US6487348B1 (en) * | 1999-11-12 | 2002-11-26 | Fitel Usa Corp. | Variable fiber count optical fiber cable core |
| US6421487B1 (en) * | 2000-05-03 | 2002-07-16 | Alcatel | Reinforced buffered fiber optic ribbon cable |
| FR2941812A1 (en) | 2009-02-03 | 2010-08-06 | Nexans | ELECTRICAL TRANSMISSION CABLE WITH HIGH VOLTAGE. |
| JP2015517679A (en) | 2012-05-02 | 2015-06-22 | エーエフエル・テレコミュニケーションズ・エルエルシー | Circular and small-diameter optical cable with ribbon-type optical fiber structure |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1598438A (en) * | 1977-05-13 | 1981-09-23 | Bicc Ltd | Overhead electric transmission systems |
| GB8406636D0 (en) * | 1984-03-14 | 1984-04-18 | Bicc Plc | Flexible elongate body |
-
1991
- 1991-12-11 GB GB919126232A patent/GB9126232D0/en active Pending
-
1992
- 1992-12-10 NZ NZ245430A patent/NZ245430A/en unknown
- 1992-12-10 GB GB9225800A patent/GB2262357B/en not_active Expired - Fee Related
- 1992-12-10 AU AU30066/92A patent/AU670552B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| GB9225800D0 (en) | 1993-02-03 |
| AU670552B2 (en) | 1996-07-25 |
| GB2262357B (en) | 1995-01-18 |
| GB2262357A (en) | 1993-06-16 |
| AU3006692A (en) | 1993-06-17 |
| GB9126232D0 (en) | 1992-02-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5229851A (en) | Optical fiber cable with large number of ribbon units containing optical fibers and enclosed in tubes | |
| US4491387A (en) | Overhead electric and optical transmission systems | |
| US4230395A (en) | Optical cables with loosely housed optical guides | |
| EP0438684B1 (en) | Unitube optical fiber cable | |
| US6785450B2 (en) | Self-supporting fiber optic cable | |
| US4143942A (en) | Fiber optic cable and method of making same | |
| EP0562770B1 (en) | Hybrid communications cable for enhancement of transmission capability | |
| US6101305A (en) | Fiber optic cable | |
| US6137935A (en) | Method for fabricating an optical cable | |
| EP1223448B1 (en) | Optical fibre cable with support member for indoor and outdoor use | |
| US4693551A (en) | Dielectric strength elements for loose tube optical fiber cable | |
| EP0227326A2 (en) | Optical fiber communications cable | |
| US5649043A (en) | Optical fiber cable having truncated triangular profile tubes | |
| AU7628998A (en) | Combination optical fiber cable | |
| GB1598438A (en) | Overhead electric transmission systems | |
| CA2051055A1 (en) | Electro-optical overhead cable with 24 and more light wave guides | |
| RU2141123C1 (en) | Suspension fiber-optical cable | |
| AU1375192A (en) | Tight buffered fiber optic groundwire cable | |
| CA2209508C (en) | Improved optical fiber cable | |
| GB1598540A (en) | Electro-optical cables | |
| GB2159291A (en) | Optical fibre cables | |
| GB2085188A (en) | An improved optical cable | |
| AU670552B2 (en) | An improved composite overhead electric and optical conductor | |
| GB2215480A (en) | Optical fibre cable element | |
| GB2262358A (en) | Conposite overhead electric and optical fibre conductor |