Fiber Optic Communication Lines for OHTL

Nowadays fiber optic cables (FOC) are widely used for fast-speed communication lines.

For data transmission glass or plastic fibers are used. Laser-type source transmits light waves along the fiber. Fiber optic cables provide high security of transmitted data, wide bandwidth and require little space. May be viewed as physical means of ground communication in future.

In the world there are used six types of cables for OHTL:

OPGW - FOC in ground wire

OPPC - FOC in phase conductor

Wrap GW - FOC wrapped around ground wire

Wrap PC - FOC wrapped around phase conductor

Externally attached FOC

ADSS - All-Dielectric Self-Supporting Cable

For fiber optic communication lines on OHTLs OPGW cable is used most often. In this case FOC has two functions: lightning protection of OHTL and provision of telecommunication.

Usage of FOC on OHTLs eliminates emissions and all other types of pollutions of the environment. It does not require additional natural resources, apart from the territories and air space already occupied by OHTLs.

Brief description of the technology of erection of OPGW used by the JSC "UralElektroSetStroi"

OPGW is erected on the towers of OHTL by means of modern technology of "under the tension" stringing:

Pulleys with pilot line are suspended at the ground wire peaks of the towers of OHTL being erected (at working OHTLs the existing ground wire may serve as pilot line). Special antitwisting braided rope or nylon rope is used as pilot line for stringing OPGW.

On both sides of the section being strung one puller and one tensioner machines by "Tesmec" with built-in dynamometers are placed.

Before stringing the pilot line is connected with the OPGW with swivel joint and sock joint. For prevention of OPGW twisting during stringing operations counterweights are used at the end of pilot line.

the stringing of the OPGW along the section is performed with the help of puller machine which spools the pilot line. Speed and tension of stringing are chosen in accordance with OPGW characteristics, properties of the OHTL and project requirements. The tensioner machine governs the working tension to provide constant sagging force.

After stringing of the section, OPGW is fixed with the tension clamp at the tower from the tensioner side. Free ends of the OPGW at each side of the section are left of sufficient length for welding the optic fibers in the connector on the ground.

After clamping of the OPGW at the tensioner side it is sagged and clamped with the tension clamp at the puller side of the section. Then it is transferred from pulleys to the suspension clamps on suspension towers.

Connection of OPGW is performed in specialized mobile laboratory (mobile laboratory for erection and testing MLET). Complete connectors are fixed to the towers.