Bicc Public Limited Company

Ccs Technology Corporation

Bicc Public Ltd. Company

Arago Technology Limited

Simon M Rowland

David John Walker

David Chambers

Ian Cotton

Md Nor Ramdon Bin Baharom

Nicholas Weatherby

Matthew Thorne

Ian Nichols

Ian G Knight

John Richards

Colin A Platt

Md Nor Baharom

Nor Ramdon Bin Baharom

An electrically insulating cross-arm for a tower for high-voltage power networks. The cross-arm includes an insulating structural member for attachment to the tower body and to support a conductor cable. The insulating structural member comprises a solid rigid spine extending along a long axis having cross sectional profile, normal to the long axis, having a second moment of area of its cross sectional profile about every axis normal to the long axis and dissecting its centroid has a value of A/2&#x3c0; or more, where A is the area of the cross sectional profile. The structural member provides resistance to bending and compressive buckling and allows conductors to be safely supported at reduced tower height. T and Y shaped cross sections provide water run-off and inhibition of organic growth. The structural members are also generally useful as insulator members in high voltage power networks.

Structural insulator

An electric conductor incorporates at least one optical fibre and has a central axial element with at least one layer of elements helically stranded about it. At least one of the elements, preferably the central axial one, includes at least one optical fibre which is enclosed in a longitudinally extending welded metal tube (typically stainless steel). A second metal tube of greater thickness and higher conductivity than the welded metal tube and having an unwelded longitudinal seam surrounds the welded tube. The second tube is typically of aluminium and served to increase the diameter of the element so that a greater range of useful conductor sizes can be formed by using it in conjunction with appropriately chosen wire diameters.

Electric conductors incorporating optical fibres

Optical cable for avoiding dry-band arcing

A linear element (1,61) suitable for extending between, and being supported by, towers of an overhead electrical power transmission system, includes one or more electrically semiconductive components (54, 62) that cause the element to have a linear resistance of 0.05 to 100 Mohms m.sup.-, and which exhibit a negative temperature coefficient of resistance. The element may be a rope used for stringing up conductors of the system or it may be an optical cable. Preferred materials for forming the semiconductive components include carbonaceous fibre tows formed from pyrolised acrylonitrile fibres. The element has a controllable and reproducible resistance for reducing or eliminating dry-band arcing.

Semiconductive linear element including partially pyrolised

An overhead electrical power and optical transmission system, comprising overhead electrical phase conductors (2) extending between and supported by towers (10), and at least one optical cable (1) that extends between and is supported by, the towers. Each optical cable has a resistive element (12) that is removably supported thereby and which extends from a tower (10) where it is earthed part of the way along the span of the optical cable, and the resistive element has the necessary length and conductivity such that if a dry band (6) occurs on the cable at the end of the element, the potential difference (VG') across the band is insufficient to form an arc, such that any induced current is insufficient to sustain any arc that may occur across the dry band.

Method and apparatus for preventing dry band arcing in a combined

Overhead optical transmission system

In an overhead optical transmission system in which an optical cable is freely supported between towers employed to support overhead electric power transmission lines and in which each end of the suspended length of optical cable is secured to a tower by means of a metal termination fitting which surrounds and is clamped on a part of a length of the optical cable at or near this end, each metal termination fitting of the cable over a part of the length of the fitting extending to the end of the fitting remote from the tower and an immediately adjacent part of the length of the optical cable are surrounded by a shield of an electrically conductive metal or of a semi-conductive plastics material sufficiently conductive to reduce arcing and/or joule heating. Preferably, a preformed helix constituting a damper extends lengthwise of the shield and may extend lengthwise of the part of the length of the fitting, the overall outer diameter of the preformed helix over a part of its length remove from the fitting increasing smoothly in a direction away from the fitting. Where the shield is a preformed helix of a semi-conductive plastics material, the preformed helix may be so shaped over a part of its length remote from the fitting that the preformed helix serves the dual purposes of a shield and a damper.

Growing community of inventors

Tarporley, United Kingdom

Simon M Rowland