Abstract: A repair line for repairing a closure defect in a metal tube containing at least one transmission optical fiber which includes a repair station having a tube conditioning system for bending and tensioning a portion of the tube including the defect and a laser for welding point by point along the defect with the minimum heat input at each point.

Abstract: A method of repairing a closure defect in a metal tube containing at least one transmission optical fiber entails bending and tensioning a portion of the tube including the defect and laser welding point by point along the defect within the bent portion with the minimun heat input at each point.

Abstract: Junction box for joining the ends of two underwater optical fiber cables by welding, comprising two clamps 1, 2 connected by a tubular sleeve 3, and a central hollow mandrel 17 for securing the welds, wherein said mandrel comprises a slack chamber 15, 16 in between each clamp and one end of the mandrel. Such junction boxes are mainly for use in the junction of underwater telecommunication cables.

Abstract: A device for joining an underwater optical fiber cable and a repeater comprising a fiber feed-in cable, the end of said underwater cable being secured in a jointing block by means of a tapered ferrule and hard-setting resin filler, said device comprising a slack chamber for storing surplus lengths of optical fiber, said slack chamber interior being bounded on the underwater-cable-side by a storage canister having a bulged internal wall the radius of curvature whereof is everywhere greater than or equal to the minimum acceptable radius of curvature for the optical fibers, and on the fiber-feed-cable-side by a plug having a conical internal surface. Device is mainly applicable to the joining of undersea telecommunications cables.