What are the main methods of laying telecommunications optical cables?

Due to varying construction conditions and requirements, communication optical cables are laid using different methods in different scenarios. Common laying methods include direct burial, aerial installation, conduit installation, submarine installation, and installation within central offices.

1 Direct Burial

Direct burial refers to the method of laying optical cables directly into the ground. Typically, in ordinary or hard soil, optical cables must be buried at a depth of 1.2 meters or more below the ground surface.

Directly buried optical cables generally use the GYTA53 structure, which adds a chromium-plated steel tape and a polyethylene outer sheath to the outer layer of a standard GYTA optical cable, as shown in Figure 2. thereby providing the cable with enhanced protection.

2. Aerial Installation

Aerial installation of optical cables involves suspending the cables at a height of 3.0 to 8.0 meters above the ground using support structures such as utility poles. The primary support structures for aerial cables are utility poles, with pole spacing (the distance between adjacent poles) generally around 50 meters.

The construction cost of overhead optical cables is relatively low, but their safety is also lower. At road crossings, they are often prone to being severed by vehicles that are too tall; during floods, entire stretches of poles and cables are frequently washed away.

Self-supporting Overhead

Self-supporting overhead refers to a cable installation method that uses self-supporting optical cables with high tensile strength. These cables do not require suspension via steel strands (as shown in Figure 7) but are directly secured to support structures such as utility poles. Self-supporting aerial installation is commonly used in scenarios where it is inconvenient to install steel strands, such as beneath power poles, in areas with high atmospheric corrosion, or in sections where no capacity expansion is required for an extended period after installation.

3 Duct Installation

Duct installation of optical cables typically refers to the process of laying optical cables within underground communication ducts using pulling or air-blowing methods. Underground communication ducts generally consist of a cluster of pipes buried beneath the ground and manholes (or access ports) at both ends of the cluster, as shown in Figure 10. The pipe cluster usually comprises one or more plastic pipes. Depending on the construction area and segment length, underground communication ducts are typically classified into urban ducts and long-distance ducts.