What Are The Main Laying Methods of Fiber Optic Cable?

Due to different construction conditions and construction requirements, communication cables in different scenarios will take different laying methods, common laying methods include: direct burial, aerial, pipeline, underwater and bureau and so on.

1 direct burial laying

Direct burial, also known as direct burial, refers to the cable directly buried in the underground soil in the laying method. Usually, in ordinary soil and hard soil, fiber optic cable needs to be buried below 1.2 meters from the surface.

When burying fiber optic cables directly, it is necessary to dig out a cable trench that meets the requirements, and then place the buried fiber optic cable at the bottom of the trench, and then backfill the soil. In order to facilitate the maintenance to find the laying position of the cable, after backfilling the soil, every about 50 meters in the surface buried markers for marking. Directly buried fiber optic cable can be laid manually or mechanically.

Directly buried fiber optic cable is generally used GYTA53 structure, this structure is equivalent to the ordinary GYTA fiber optic cable sheath outside the increase of chrome-plated steel strip and polyethylene outer jacket, so that the cable has better protection performance.

In the 1990s, the country began large-scale construction of long-distance (including the current trunk and two trunk) cable lines, long-distance cable lines were mainly used in direct burial laying. Direct burial cable line security is better, but the construction and maintenance costs are high, difficult to expand capacity, so, gradually replaced by long-distance plastic pipe air blowing and other laying methods, currently in some sparsely populated, and should not be used in the overhead laying method of the passage (such as: grasslands, deserts) is still a small amount of construction.

From the point of view of project management, the field buried long-distance plastic pipe construction content and direct burial cable is similar, therefore, some owners tend to bury long-distance plastic pipe through the field blowing cable as a direct burial cable line project management, but from the cable laying method should belong to the pipeline cable laying.

2 aerial laying

Aerial fiber optic cable refers to fiber optic cable relying on poles and other supports, so that the cable is suspended from the ground 3.0 meters to 8.0 meters of space. Aerial fiber optic cable using the support is mainly electric poles, pole distance (distance between adjacent poles) is generally about 50 meters.

Aerial fiber optic cables are less expensive to construct, but also less safe. In the crossing of the road is often easy to be super-high vehicles hanging off; in the event of flooding, often occurring in succession of poles washed out of the road.

Overhead laying mainly takes two ways: the use of steel strand attached and self-supporting overhead.

(1) the use of steel stranded wire attached

Aerial fiber optic cable is mainly used in the way of steel stranded wire attached to the laying, this way you need to fix the steel stranded wire on the pole, and then the fiber optic cable through the cable hooks attached to the steel stranded wire. Usually, each pole can be fixed on 1 to 4 stranded wire, each stranded wire can be attached to 1 to more than one fiber optic cable.

Aerial fiber optic cable is generally used GYTS structure, in the fiber optic cable sheath and core between a layer of steel armor), so that the cable has a certain degree of anti-bird pecking and rodent-proof ability.

(2) Self-supporting overhead

Self-supporting overhead refers to the use of a greater tensile strength of self-supporting optical fiber cable, the cable does not need to be attached through the stranded wire, directly fixed in the pole and other supports on a cable laying method. Self-supporting aerial often used in the scene is not easy to lay steel stranded wire, such as: power poles under the road, the air corrosive region, or fiber optic cable laying a longer period of time does not need to expand the section.

Along the high-voltage power lines or the need for large-span laying scenarios, self-supporting fiber optic cables are usually used ADSS structure, the cable's main load-bearing components for the inner sheath and the outer sheath between the aramid.

In the need for low-cost construction scenarios, self-supporting cables usually use the "8" structure, the main load-bearing member of the cable for the cable in the wire.

3 pipe laying

Pipe laying of fiber optic cable usually refers to the fiber optic cable by traction or air blowing, the cable is laid in the underground communication pipe. Underground communication pipe is generally buried in the ground under the tube group and tube group at both ends of the man (hand) hole composition. The pipe group usually consists of one or more plastic pipes. According to the different construction areas and section lengths, underground communication pipelines are usually divided into municipal pipelines and long-distance pipelines.

Intra-city pipelines are usually constructed in urban areas, suburban areas or market towns where communication services are denser, with a segment length of about 100 meters. Fiber optic cables are usually laid in the pipeline by manual traction or mechanical traction.

Long-distance pipeline is usually constructed in the field, the pipe is made of 40mm/33mm silicon core plastic pipe, and the section length is about 980 meters. Fiber optic cables in the pipeline need to be laid by air blowing. Air blowing cable laying is compressed air blown into the silicon core tube, so that the penetration of the fiber optic cable with the high-speed airflow together in the silicon core tube into a suspended state, at the same time, blowing the cable machine tracked conveyor mechanism clamped with the fiber optic cable forward transport.

In order to improve the utilization rate of the pipe hole resources, along the highway communication pipeline, has been widely used in the micro-pipe and micro-cable laying method.

4 other laying methods

In addition to direct burial, pipe, overhead three common laying methods, in recent years, with the construction of high-speed rail lines, fiber optic cables along the high-speed rail channel laying scene is also more and more. In addition, direct buried lines (direct buried cable and direct buried silicon core pipe) across the river involves underwater laying, cable into the station also needs to be laid in the station, limited to the length of this paper on the other ways of laying fiber optic cables are not introduced in detail.