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: In order to allow an optical cable to be accessed by spur cables at various points along its length after it has been laid, connection housings are provided at intervals along its length. A loop of the main cable is passed into each housing so that at a later date there is an excess of cable to enable connections to be made to it. Each housing contains fittings such as manifolds and organizer trays where the optical fibers are spliced and includes several access ports which are covered over until it is required to connect a spur cable to the main cable.

Abstract: A junction box for linking a first optical communications cord with two or more second optical communications cords, includes a sealable, flat housing having internal formations for organizing optical fibres; terminals, preferably glands, along one edge of the housing for connection to the first and/or second optical communications cords; passive optical components including a 1.times.2 fiber-optic coupler all interconnected by internal optical fibres with the terminals, the internal fibres all being organized together in a single loop parallel to the major faces of the housing; and clamps along the inside of at least one different edge of the housing between the loop and the edge wall of the housing, retaining the passive optical components.

Abstract: Method of splicing optical fibres having a glass core and at least one plastics cladding layer comprises: stripping the or each cladding layer from the fibre ends, fusion splicing the bare fibre ends, placing the splice region in an open channel of a flexible mould, the channel being of uniform section, filling the gap between the bare, splice region and the inner wall of the channel with a curable plastics material, closing the flexible mould so that the channel walls close together and assume an internal shape complementary to that of the cladding layer or layers whereby to expel the surplus plastics material, curing the plastics material remaining within the mould, and opening the mould.

Abstract: A comb-like support structure for optical cords has slots of uniform width having resiliently-compressible walls which grip frictionally the cords. Intermediate portions of the cords are simply pushed into corresponding slots from one end. The cord support is conveniently mounted in one wall of a distribution frame for optical fibre transmission systems.

Abstract: A distribution frame for an optical fibre transmission system comprises a cabinet incorporating at each side at least one side panel supporting a surplus length of cable, a pair of inner panels spaced from the side panels and organizer trays, arranged to accommodate surplus lengths of fibres from the cables, supported between the inner panels, the latter panels also supporting couplers for enabling the cable fibers to be connected to further fibres, the ends of which are accommodated in the spaces between the inner and side panels.