Abstract: A wrist-wearable detection device 2 for detecting a electrical potential of a pre-set magnitude within a certain proximity to the detection device. Detective circuitry 1 has a detection coil 3 that detects an electrical potential field generated by an electrically active field. The electrical potential is analyzed and compared by control circuit 20 against pre-set levels such as 60 Hz frequency, which in turn activates audible, visual (LED light) and for a vibratory indicator when in the presence of an electrical potential of a pre-set magnitude. The detector 2 is preferably incorporated into a wrist watch with controls (16, 17 and 18) which can be easily worn and thus always available for use.

Abstract: In a submarine repeater for a fibre optical transmission system, the cable and tail fibres at the A and B ends of the repeater are accommodated in storage structures. Each structure comprises two bodies 12, 13 (FIG. 1) having circular surface grooves or channels 125, 135 in which respective cable or tail fibres are stored. Straight channels 126, 136 provide communication between the circular channels and accommodate splices between the fibres stored therein.

Abstract: A joint for an optical cable has a tapered hollow insert (26) with high friction surfaces (26D) so that after jointing the optical package, the cable strength members (6A 6B) can be clamped onto the high friction surfaces of the insert by a wedging action. The surfaces prevent strength members moving axially and imposing longitudinal strain on the jointed package, and the arrangement is such that the differential strain between the strength member layers are minimized if not eliminated.

Abstract: A joint assembly for an underwater optical fibre cable provides a limited-movement sliding clamp arrangement for the kingwire ends (9, 11). The sea casing provides the main tensile strength member of the joint and a split liner provides the main compressive strength of the joint. Tapered clamps (22, 12, 27) are incorporated into bulkheads of the joint assembly and coupled with ring nuts which screw into the sea casing and cause the bulkhead to abut the split liner. First and second parallel storage plates (1,5) store excess fibre and fibre splices.