Abstract: A method of manufacturing an optical fiber preform includes: producing a core rod having a core rod diameter; inserting the core rod into a glass fluorine-doped intermediate cladding tube so as to form a core assembly, the intermediate cladding tube having an inner diameter and an outer diameter, wherein the inner diameter is larger than the core rod diameter, the radial difference between the inner diameter and the core rod diameter defining an annular gap; and applying a negative pressure inside the annular gap; and forming a core preform by heating the core assembly to collapse the intermediate cladding tube around the core rod while maintaining the negative pressure, wherein heating includes moving a heater outside the intermediate cladding tube and along an axial direction of the same, and forming an overcladding region surrounding the core preform so as to form an optical fiber preform.

Abstract: A method of jointing two high voltage impregnated cables may include exposing an impregnated cable insulation layer of cable ends by removing at least one protecting layer and an outer semiconducting layer; exposing a terminal length of conductors of the cable ends by cutting a portion of the impregnated cable insulation layer and by removing an inner semiconducting layer; mechanically and electrically connecting the conductors; filling at least in part a space left by the removed impregnated cable insulation layer with a conductive insert; providing an intermediate semiconducting layer to surround the conductive insert and abutting on portions of cable insulation layers adjacent to the conductive insert; applying a stratified insulation, impregnated with a second viscous compound, overlapping the exposed impregnated cable insulation layer of the cable ends and covering the intermediate semiconducting layer; electrically screening the conductors; and tightly containing the first and/or second viscous compound

Abstract: An enclosure for housing and fastening a length of optical cable, the optical cable having an outer sheath and a flexible strength member, includes a fixing element and a retention assembly, the fixing element being adapted for engaging a portion of the outer sheath and the retention assembly being adapted for fastening the flexible strength member. The fixing element and the retention assembly are independent from each other. The retention assembly includes a reel and a reel seat. The reel is adapted to receive at least one turn of the flexible strength member wound thereon and to be inserted without rotation into the reel seat. The reel seat is adapted for housing the reel. The reel seat is shaped at least partially mating the shape of the reel.

Abstract: A single-mode transmission optical fiber includes a central core region radially outwardly from a centerline to a radius r1 and having a positive relative refractive index ?1; a first inner cladding region extending radially outwardly from the central core to a radius r2 and having a negative relative refractive index ?2; a second inner cladding region extending radially outwardly from the first inner cladding region to a radius r3 and having a non-negative relative refractive index ?3; an intermediate cladding region extending radially outwardly from the second inner cladding region to a radius r4 having a negative relative refractive index ?4 larger in absolute value than the relative refractive index ?2; and an outer cladding region extending radially outwardly from the intermediate cladding region and having a non-negative relative refractive index ?5; wherein the relative refractive index ?2 of the first inner cladding region is ?0.1·10?3 to ?1.

Abstract: Method and system for monitoring parameters of a cable system of an electric power transmission system, wherein: a plurality of monitoring nodes is associated with different monitoring points of the cable system; the monitoring nodes are operated alternatively in a sleeping mode and in an active mode; in the active modes the monitoring nodes acquire values of at least one of said parameters and process the acquired values so as to generate corresponding output data; a central unit collects the output data generated by the monitoring nodes; the output data generated by the monitoring nodes are sent from the monitoring nodes, when in active mode, toward the central unit by making them pass from one of the monitoring nodes to another, by starting from the monitoring node that generates the output data until a last of the monitoring nodes, which forwards the output data to the central unit.

Abstract: A process for manufacturing a jointing assembly for medium or high voltage electrical cables may include: forming a tubular element made from semi-conductive material; cutting out of the tubular element first and second cylindrical elements; machining an end portion of the first and second cylindrical elements to provide the end portions with an at least partially rounded profile; arranging the first cylindrical element at a radially inner surface of an elastomeric sleeve made from dielectric material; arranging the second cylindrical element at a free end portion of the elastomeric sleeve, spaced apart from the first cylindrical element, with the at least partially rounded profile end portion of the second cylindrical element facing the at least partially rounded profile end portion of the first cylindrical element; and elastically expanding the elastomeric sleeve by inserting at least one removable support element in a radially inner position with respect to the elastomeric sleeve.

Abstract: A jointing assembly for electrical cables may include: a connector extending about a longitudinal axis and provided, at at least one end portion thereof, with at least one housing seat for at least one free end of a respective electrical cable; and a shrinkable sleeve coaxially arranged in a radially outer position with respect to the connector. The shrinkable sleeve may be held in a radially expanded state by at least one removable support element radially interposed between the connector and the shrinkable sleeve. The connector may be mechanically coupled to the at least one removable support element by at least one stop element that radially projects from at least one of the connector and the at least one removable support element, and that contacts the other one of the connector and the at least one removable support element.

Abstract: It is disclosed an optical cable for communications including at least one micromodule, the micromodule including a retaining element and number N of optical fibers housed in said retaining element. The diameter of a circumference encircling the number N of optical fibers is typically 90% to 95% of an inner diameter of the retaining element. The retaining element consists essentially of a film grade polymeric material having an elongation at break equal to or higher than 500%, a melt flow index (MFI) lower than 3 g/10 min, and a density lower than 1 g/cm3.

Abstract: A process for manufacturing fiber optic overhead ground wire cable may include: providing an optical core; providing a reinforcing structure consisting of at least one layer of wires onto the optical core, wherein at least part of the wires are clad with first metallic material; extruding an outer layer onto the reinforcing structure, wherein the outer layer is made of second metallic material having a softening point substantially similar to a softening point of the first metallic material; and cooling the outer layer immediately after extruding the outer layer. A fiber optic overhead ground wire cable may include: an optical core comprising a plurality of optical fibers housed in an inner tube; and a reinforcing structure consisting of at least one layer of wires stranded onto the optical core. The cable may be substantially devoid of interstices between the at least one layer of wires and the inner tube.

Abstract: A microbundle optical cable such as, a riser cable, includes an outer jacket and a plurality of microbundles housed in the outer jacket. At least one of the microbundles includes an optical fiber ribbon enclosed in a microbundle coating. The at least one microbundle includes a longitudinal axis and a cross-section taken on a plane substantially perpendicular to the longitudinal axis. The cross-section may include a first dimension and a second dimension. The first dimension is higher than the second dimension. Therefore, the cross-section shape is an elongated cross shape.

Abstract: A method of coloring optical fibers during the optical fiber drawing that includes the steps of feeding a natural fiber coating material and a colorant to a mixer; mixing the natural fiber coating material and the colorant in the mixer to obtain a colored coating material; and supplying the colored coating material to a coating die. The feeding step includes exerting on the natural fiber coating a first gas pressure variable with at least one fiber drawing parameter; and exerting on the colorant a second gas pressure variable with at least one fiber drawing parameter.

Abstract: A valve device for use in a feeding apparatus releases raw material into raw material processing machinery for the manufacture of high-voltage cable. The valve device includes a valve body including a first valve member having a conical shape and including at least one opening extending between a tip of the first valve member and a corresponding base portion of the first valve member, and a second valve member including at least one cover element. One of the valve members is rotatable with respect to the other valve member between a first operating position in which the at least one cover element uncovers the at least one opening, thereby allowing the raw material to flow through the valve device, and a second operating position in which the at least one cover element covers the at least one opening, thereby preventing raw material from flowing through the valve device.

Abstract: A fire resistant optical cable includes: a plurality of optical fibers; at least one tubular layer of a ceramifiable material surrounding the plurality of optical fibers; and at least one flame shielding layer surrounding the tubular layer. The tubular layer of the ceramifiable material is able to mechanically protect the optical fibers not only during heating but also when the fire is extinguished, since it forms a sufficiently robust layer to withstand the mechanical stresses caused by the collapsing of the materials still surrounding the cable, especially in the transition portions between hot and cold zones. The tubular layer of the ceramifiable material is protected by means of at least one flame shielding layer which prevents the flames from directly acting on the ceramifiable material.

Abstract: Apparatus and method for generating electric energy in an electric power transmission system includes an AC cable including a core, wherein a portion of the core is partially surrounded by an apparatus including a ferromagnetic body and an electrically conducting winding. The ferromagnetic body extends along a longitudinal axis and has, in a cross section taken along said longitudinal axis, a shape defined by an arc. The electrically conducting winding is wound around the ferromagnetic body to form turns in planes substantially perpendicular to the arc.

Abstract: A process for manufacturing submarine optical communications cable may include: providing an optical core; providing a reinforcing structure consisting of at least one layer of wires onto the optical core, wherein at least part of the wires are clad with first metallic material; extruding an outer layer onto the reinforcing structure, wherein the outer layer is made of second metallic material having a softening point substantially similar to a softening point of the first metallic material; and cooling the outer layer immediately after extruding the outer layer. A submarine optical cable may include: an optical core comprising a plurality of optical fibers housed in an inner tube; and a reinforcing structure consisting of at least one layer of wires stranded onto the optical core. The cable may be substantially devoid of interstices between the at least one layer of wires and the inner tube.

Abstract: An optical cable has a cable core including at least one tube loosely accommodating optical fibers, the at least one tube being accommodated within a jacket embedding at least two strength members, the cable core and the jacket comprising combustible material. A ratio of core combustible material/jacket combustible material is lower than 60 vol %. The jacket is made of a composition having hardness of at least 60 Shore D and a LOI higher than 35%.

Abstract: A method for detecting faulty laying down of an optical cable exhibiting a measured cut-off wavelength includes providing an optical cable for transmitting optical signals including at least one single-mode optical fiber having an attenuation equal to or larger than a first threshold value as measured when wound for one turn around a bending radius equal to or smaller than 5 mm at at least one predetermined test wavelength, the test wavelength being smaller than the measured cut-off wavelength, and an attenuation smaller than a second threshold value as measured when wound for one turn around a bending radius equal to at least a minimum bending radius at an operative wavelength equal to or larger than the measured cut-off wavelength; laying the optical cable; and measuring the attenuation in the at least one optical fiber at the predetermined test wavelength.

Abstract: An optical fiber cable, includes at least one optical fiber and a cable connector at a cable end, and a removable cap removably couplable to a free end of the cable connector. The cap includes a recess adapted to receive and accommodate an anchor element of a cable pulling rope, and to retain the anchor element against traction when the pulling rope is tractioned.

Abstract: A cooling system for cooling a power transmission system that includes a cable configured to carry a current corresponding to a transported electric power may include: a cooling device configured to remove heat from the power transmission system; a power supply system configured to extract a power fraction from the cable and configured to supply the cooling device with the power fraction; and a control unit configured to control an amount of the extracted power fraction in response to a parameter of the electric power. When the parameter is higher than a threshold, the extracted power fraction is equal to a first value that depends on the electric power carried in the cable through a first function. When the parameter is lower than the threshold, the extracted power fraction is equal to a second value that depends on the electric power carried in the cable through a second function.

Abstract: A single-mode optical fiber for transmitting optical signals includes a central core region for guiding the optical signals, and a cladding region surrounding the core region and including a void-containing annular layer containing randomly distributed voids, wherein the void-containing layer is doped with fluorine at a concentration of less than 1 wt % and has a radial thickness equal to or smaller than 3 ?m.