Abstract: A splice tray for accommodating optical fibers comprises a body with a plurality of splice holders at fixed locations thereon, the body having fiber access points at which fiber can enter and leave the body. Fiber paths are provided on the body leading from the access points to and from each splice holder, and each holder is adapted to receive and hold a splice reinforcer within which a fiber splice is present. The length of fiber is accommodated on either side of the splice. An adapter is used with a clip-on power meter to take readings of the transmissivity of fibers stored on storage leaves mounted on the tray body.

Abstract: A cable routing has a body (10) and a plurality of cable passages (22) through the body. Each passage has an entry socket (24) adapted to receive a cable end (20), an exit (26) in line with the entry socket and a lateral opening (28). Each passage also has a cross-sectional reduction between the entry socket (24) and the exit (26) to limit longitudinal movement of a cable (20) along the passage.

Abstract: A system for installation of optical fibre transmission lines into ducts by feeding coiled optical fibre packages from a container with an annular configuration. The optical fibre package comprises filamentary material coiled into a series of turns each offset from preceding turns and containing 360 degrees of torsion.

Abstract: A system for installation of optical fibre transmission lines into ducts by feeding coiled optical fibre packages from a container with an annular configuration. The optical fibre package comprises filamentary material coiled into a series of turns each offset from preceeding turns and containing 360 degrees of torsion.

Abstract: 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.

Abstract: 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 performance 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.

Abstract: An optical fiber connection terminal for use in the office or domestic environment includes a three-part module, having a base unit, an organizer unit and a top unit. An optical fiber cable, such as a blown fiber cable, is brought to the base unit where both the outer covering and the secondary coated optical fibers carried by the cable are secured against tensile forces. The three units of the module are then designed to store fiber, to hold splice protectors where necessary, and to provide a well protected route for the fibers from the cable to an easily accessible connection point for customer use in the top unit of the module. Connection or termination of each fiber at the connection point can be made and remade, drawing spare fiber length from a storage area in the module without disassembling the module. An important part of the module lies in a cam action clamping mechanism for retaining fiber within the module.

Abstract: A technique for handling filamentary material, specially optical fiber packages, in which the filamentary material is coiled into an annular pan in a series of turns each of which is offset from preceding turns. The turns each contain 360 degrees of torsion which is relieved when the filamentary material is paid out from the pan. A rosetting head for laying the pattern sequence is located in the center of the annular pan.

Abstract: An optical fibre storage system comprising a container in which turns of fibre (4) are wound in a substantially helical formation, the diameter of the turns and container being such the turns of fibre are maintained in position by their natural resilience pressing them outwardly against the inside of the container (5). The inside of the container may be coated to aid location of the turns. In another embodiment an inflatable member located within the turns is inflated to press against them to aid positional stability. A source of gas may be connected to the container to enable propulsion of the fibre out of the container in a duct, or the container itself may be pressurized.

Abstract: Apparatus is described for inhibiting fluid flow and fibre package (3) motion in a fibre blowing operation. The apparatus comprises a fluid flow passageway (8) with a valve (9), and a bypass passageway (7) for the fibre package (3) in the vicinity of the valve (9). A flexible membrane (11) is interposed between the fluid flow passageway (8) and the fibre bypass passageway (7), which membrane bears against the fibre package (3) and closes the bypass passageway when the valve (9) is closed.

Abstract: A seal for a duct (7) containing a transmission line package (P) comprises a flexible member (2) disposed in a connector (1). The flexible member (2) has a waisted portion that collapses inwardly onto the transmission line package (P) to form a gas seal up to pressures of about 2 bar, above which the waisted portion yields to permit removal or insertion of the transmission line package, for example by the fibre blowing technique. Vents (8) are provided in the connector (1) so that an increase in ambient pressure externally of the connector increases the resistance of the waisted portion to opening. The arrangement may be used to maintain water tightness or pressure differentials over a bulkhead.

Abstract: A technique for detecting faults, blockages or holes, in a duct (6). A burst of compressed gas is injected into the duct and the decay of the pressure pulse monitored by a transducer at the gas burst launch end of the duct. A reference decay pressure that would be expected for a perfect duct is generated and the monitored decay is compared with the reference decay for deviation. A perforated duct exhibits greater pressure decay and a blocked duct less pressure decay than a perfect duct. The time occurrence of the deviation indicates the location of the fault. The signal level indicative of the pressure after a predetermined interval may also be used to measure the air friction or blowability within the duct.

Abstract: A mounting assembly (1) for optical equipment comprises a plurality of trays (2) detachably hinged together. Each tray (2) may be adapted to carry optical components as well as optical fibre splices and they can be hinged together into a stack in one of a number of different configurations, allowing convenient access for both installation and maintenance. The assembly (1) finds particular application in optical communications equipment.

Abstract: A clamp assembly for securing the ends of longitudinal tensile load-bearing elements comprises a pair of rings having complementary tapered surfaces. When assembled, one ring seats coaxially inside the other ring and the elements are gripped between the tapered surfaces. The outer, tapered surface of the inner ring is roughened and embedded in the surface of the elements so that load on the elements acts preferentially to draw the inner ring more tightly against the inner, tapered surface of the outer ring. An outer collar engages the outer ring with a flange to retain the assembly. The assembly finds particular application as an armour clamp for a submarine telecommunications cable.

Abstract: A corner guide comprises a pair of hinged panels (1, 2) with an embedded duct (6) through which an optical fibre (7) can be threaded. The corner guide, for guiding an optical fibre (7) or the like around a corner (9) whose radius of curvature is less than a permissible minimum radius of curvature Rp for the fibre (7), guides the fibers (7) by means of the duct (6) along a path which extends into three dimensions. At the corner at the hinge between the panels (1, 2), the duct (6) passes through an "x-y" plane containing the corner at an angle for instance of 70.degree.. This enables an arrangement wherein the projection of the duct (6) onto the "x-y" plane includes a bend whose radius of curvature is less than Rp although the path itself does not include such a bend. The invention finds particular application in optical fibre installations in homes or offices, wherever a fibre has to turn a corner, for instance at the corner of a room.

Abstract: Optical fibre joints to an optical fibre submarine cable repeater are made outside the repeater housing in a separate flexibly-connected jointing arrangement. Thus, if repairs are needed, new fibre joints can be made without the need to rethread an entire gimbal assembly and disassemble an entire repeater housing and/or without the need to splice in an extra length of optical fibre cable thus incurring extra joint losses due to the repair.

Abstract: A submarine cable joint 1 comprises an elongate coupling element 8 each end of which is connected to the annular tensile layer 28 of cables 2, 3 to be joined. Fibre tails 4, 5 from the cables are led out of the coupling element and wound round bobbin 20 for splicing.

Abstract: A sealing assembly for an optical fibre feed through inhibits passage of water or gases via a fibre's protective sheath while preserving mechanical protection of the fibre (A--A') of the fibre (4) is exposed by removal of the corresponding sheath portion. Both the exposed surface of the fibre (4) and the ends (6',6) of the sheath (5) are sealed into a common bore (2) in a ferrule (1). Demountable end members (9,10) may be provided, to extend the bore (2) into which the sheath ends (6',6) are sealed. The sealing assembly finds particular application in optical fibre feed through at submarine cable repeater housing bulkheads.

Abstract: A submarine telecommunications cable assembly includes a section of main submarine telecommunications cable electrically connected to a short length of cable extending from a repeater housing, the section of main cable being armoured at least in the proximity of the repeater. The electrical connection of the section of cable to the short length of cable extending from the repeater housing is positioned at a location spaced from the repeater housing and strengthening means are provided along the short length of cable substantially increasing the flexural rigidity of the short length of cable. The armouring of the main section of cable extends over the short length of cable and the strengthening means and is anchored to the repeater housing.