British Telecommunications Public Limited Company

British Telecommunications Corporation

British Telecommunications Public

Christopher Fisk

Philip Alfred Barker

Peter D Jenkins

David J Stockton

Raymond P Smith

Christopher Nigel Munnings

John A Warren

Malcolm D Campbell

Ian Hunter

Andrew J Mayhew

Simon I Fisher

John Andrew Warren

Ramon Studd

Raymond Pentti Smith

Malcolm Donald Campbell

Simon Ivan Fisher

Andrew John Mayhew

Colin Parkin

A plurality of telecommunications connections are installed in a distribution network by connecting a series of distribution points using a multicore cable comprising a plurality of cores having a common enclosure, some of the cores carrying fiber tubes into which optical fiber may later be introduced, and other cores carrying an electrical power supply. One or more cores may be diverted from a longer cable run to serve a local distribution point by rupturing a web connecting the core to the rest of the cable, thus allowing the remaining cores to be uninterrupted at the point of divergence. An alternative embodiment intended for underground use provides for apertures to be opened in a protective sheath to expose the individual cores required to be diverted to a local distribution point.

Cable connections

Cable is installed into a duct, by increasing cross-sectional areas of subducting provided in the duct, so as to allow the cable to be received into the subducting, and then decreasing the cross-sectional area of the subducting containing the cable so as to reduce the volume occupied by the subducting in the duct. Cables may be inserted into the subducting, for example, by forcing compressed gas through the subducting, which simultaneously inflates the subducting.

Method and system of subduct and cable installation

A fiber unit coating apparatus includes a chamber into which an uncured resin coated fiber unit is passed. Microspheres mixed with air are fed into the chamber via ducts and apertures. As a result rapid and even application of the microspheres can be achieved, and the system allows controllable application of the microspheres by varying the rate of flow of the air/microsphere mixture. Positive pressure chambers are provided to prevent the microspheres from blocking the inlet and outlet points where the fiber unit enters and leaves the chamber.

Fibre coating method and apparatus

An optical fibre package suitable for installation using a fibre blowing process includes at least one optical fibre, an inner coating about said fibre, and an outer resin coating about said inner coating, said resin coating including a significant plurality of particulate inclusions at least 10 .mu.m across, wherein the concentration of the particulate inclusions is significantly greater at the outer surface of the resin coating than at the inner limit of the resin coating. The inclusions may be hollow glass microspheres or mica flakes. The relative absence of significant particulate inclusions at the inner limit of the resin coating improves the mechanical particulate of the fibre package relative to similar known packages. The presence of significant inclusions at the outer surface of the resin coating tends, during a blowing process, to increase viscous drag effects and to reduce friction between the package and the duct into which the package is blown, thereby enhancing blowability.

Optical fibres for blown installation

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Ipswich, United Kingdom

Christopher Fisk