Establishing and installing optical lines, such as All-Dielectric Self-Supporting (ADSS) cables, is essential for ensuring dependable data transfer and energy allocation in telecommunications and electrical transmission. ADSS cables, being light and adaptable, are utilized considerably in high-voltage conditions. However, they face challenges related to mechanical vibrations, environmental stressors, and installation requirements. Engineers often employ spiral vibration dampers (SVDs) and specific dead-end designs to mitigate these issues. 

Dead End for ADSS Cables

A dead end is a stopping point where the ADSS cable arrives at a mounting structure, such as a utility pole or transmission tower. Reasonable structure and installation of dead ends are essential for controlling harm to the cable and assuring long-term performance. Below are the crucial elements of ADSS cable dead ends:

Functions of a Dead End:

• Secure Cable Termination: Dead ends provide a firm anchor point for the ADSS cable, ensuring that the cable remains securely attached to the support structure.

• Load Distribution: The dead end equally shares the tensile loads throughout the cable so that no one point is exerted with pressure that may affect the fiber optic core.

• Prevention of Slippage: It also helps prevent slippage since the dead end holds the cable firmly by enveloping it, especially where it is long or exposed to the effects of wind.

Components of a Dead End:

• Preformed Helical Fittings: These are cylindrical bars coiled helically around the ADSS cable to give it mechanical support and flexibility. The rods are designed to spread the load all along the length of the cable before reaching the anchor. 

• Armor Rods: Armor rods shield the cable from mechanical abrasion and bird impact in some limited terminal designs. These rods also help prevent the cable from breaking when under tension, thus increasing its durability.

• Thimbles: Thimbles include a smooth surface upon which the cable can deflect, thereby causing minimum bending stress at the termination point.

• Anchoring Clamps: Applying these clamps helps to avoid issues such as movements or slippages, which contribute to the wear or value of the cable.

Installation of Dead Ends:

• Careful Tensioning: Correct tensioning during the installation procedure is essential. High tension puts a strain on the cable, which may damage it mechanically, while low tension may cause the cable to stretch, which exposes it to many external factors, which can also cause a lot of damage.

• Alignment: These dead ends must be positioned so that no severe bends will ensure micro bends to the fibers within the ADSS cable, a condition that reduces signal strength.

• Environmental Considerations: When installing dead ends, elements such as wind loads, temperature differences, and even ice collection must be evaluated to ensure long-term durability.

Spiral Vibration Dampers (SVDs)

ADSS cables, especially overhead cables, are vulnerable to vibrations caused by environmental influences such as wind. If such vibrations are not eliminated, they will lead to long-term mechanical cable failure and cable failure in the future. Spiral Vibration Dampers (SVDs) are chiefly employed to control this problem.

What are Spiral Vibration Dampers?

Spiral vibration dampers are helical devices made from pliable materials, such as plastic or rubber, wrapped around the ADSS cable. They are designed to counteract the effects of vibration, particularly aeolian vibrations caused by steady wind flows over the cable.

Functions of Spiral Vibration Dampers:

• Vibration Mitigation: SVDs' primary function is to reduce the amplitude and frequency of vibrations transmitted along the ADSS cable.

• Fatigue Reduction: By dampening vibrations, the Spiral vibration damper reduces the fatigue stress on the cable and its supporting structures, preventing long-term mechanical damage.

• Extended Cable Life: SVDs extend the operational life of the ADSS cable by preventing damage from dynamic forces like wind.

• Reduction of Wear: These dampers also help minimize wear and tear on the cable, especially at critical points like suspension clamps and dead ends.

Types of Vibration Controlled by SVDs:

• Aeolian Vibrations: These are high-frequency, low-amplitude oscillations caused by wind flowing steadily over the cable surface. If not adequately damped, they can lead to metal fatigue in cables over time.

• Galloping: A low-frequency, high-amplitude oscillation typically occurs when cables accumulate ice, resulting in large cable movements under windy conditions.

• Subspan Oscillations: These oscillations occur between two consecutive suspension points in the cable sections. SVDs can help reduce these localized movements.

Components and Design of Spiral Vibration Dampers:

• Helical Shape: The dampers have a spiral or helical shape, which allows them to effectively dissipate vibrational energy by inducing flexural deformation along the cable.

• Material: The most common materials used in SVDs are high-strength elastomers and plastics. These materials are chosen for their flexibility, durability, and resistance to environmental conditions such as UV radiation and extreme temperatures.

• Easy Installation: SVDs are designed for easy installation. They are typically wrapped around the cable by hand without special tools or equipment.

Final Words

The successful operation of overhead line systems in power transmission and telecommunications relies on properly using key components like Dead Ends for ADSS cables, Guy cable grip, and Spiral Vibration Dampers. These devices each play a critical role in maintaining the integrity and performance of overhead lines, whether by providing mechanical support, anchoring guy wires, or preventing damaging vibrations.