Underground – Overhead OPGW / F.O. Cabling (Design, Installation, Termination, Testing, Commissioning, Maintenance)
In energy and communication infrastructures, fiber optic (F.O.) cabling is the fundamental backbone providing high bandwidth, low latency, and stable communication over long distances. Especially in critical structures such as power transmission lines and substations/transformer stations, OPGW (Optical Ground Wire) solutions simultaneously act as a ground wire and carry the fiber communication line. Underground fiber lines offer the advantage of secure route management and protection against external influences in urban and campus projects. 2G Construction & Energy provides end-to-end services in underground-overhead OPGW and fiber optic cabling projects, from survey and design to installation and splicing-termination, measurement-testing processes, commissioning, and maintenance.
What is OPGW / F.O. Cabling?
OPGW (Optical Ground Wire)
OPGW; It is a special cable containing fiber optic cores integrated into the ground wire used in energy transmission lines. Its purpose is:
grounding/protection against lightning and fault currents,
highly reliable communication on the same line (SCADA, telecommunications, protection signals),
to ensure uninterrupted data communication in energy infrastructures.
Underground Fiber Optic (F.O.) Lines
Underground fiber lines are installed using conduit/pipe (HDPE), manhole-splice chamber structures, and route planning. They are preferred in urban areas, industrial zones, campuses, and critical facilities due to their physical security and resistance to external conditions.
Overhead Fiber (ADSS etc. solutions)
Depending on the need, overhead fiber solutions (depending on the route/line type) can also be considered in addition to OPGW. The main criteria here are mechanical loads, electrical environment, openings, and installation access.
2G Construction & Energy Service Scope
1) Survey, Route Planning and Project Design
Success in fiber optic projects begins with the correct route selection and a technical design suitable for the site.
At this stage:
underground/overhead route survey and risk analysis
evaluation of pole/line spans, mechanical loads and transition points
channel/pipe, manhole-splice chamber plan (underground)
OPGW cable selection and connection points (overhead)
ring/redundant topology requirement (critical communication scenarios)
integration with switchgear/transformer and field equipment (SCADA/protection communication)
are clarified.
2) Underground Fiber optic Cabling Application
The main goal in underground cabling is to establish a maintainable and long-lasting infrastructure that protects the cable from external influences.
The application includes:
excavation, trenching, piping (HDPE), pull rope and route layout
manhole/splice chamber construction and access layout
cable laying, protective elements and route marking
route labeling and as-built documentation
This is done.
3) Overhead OPGW Installation and Equipment Applications
In OPGW applications, the quality of mechanical installation determines long-term reliability.
At this stage:
installation of on-line equipment (hangers, tensioners, vibration dampers, etc.)
OPGW laying and tension-deflection adjustments
down-lead connections and protection details
splice closures and connection layout
are implemented.
4) Splicing, Termination and Patch Layout
The performance of fiber infrastructure largely depends on the quality of splicing and termination.
Scope:
Fiber splicing operations (fusion splicing)
Splice box/ODF layout, patch panel organization
Labeling standard, core management and port plan
End connections with switchgear/transformer communication equipment
are completed.
5) Measurement, Testing and Commissioning (OTDR Reporting)
Fiber lines are not delivered without measuring their performance. This verifies loss points, splice quality and line continuity.
At this stage:
OTDR tests and line loss analyses
Power meter/light source measurements (as needed)
Reporting and delivery document based on fiber core
Commissioning and communication verification (SCADA/telecom integration)
are performed.
6) Maintenance, Fault Detection and Repair
Fault management in fiber lines minimizes interruptions with rapid detection and accurate intervention.
The service includes:
Periodic route checks (especially hardware checks on overhead lines)
Fault point detection with OTDR
Additional repair and termination revision
As-built document updates
Where is it used?
OPGW (protection and communication) on HV/MV power transmission lines
Switchyards and transformer facilities (SCADA, teleprotection, data backbone)
Solar/Wind power plant sites (monitoring, control, central connection)
Campus/Organized Industrial Zone infrastructures (underground fiber backbone)
Critical security systems (MOBESE/EDS backbones, NVR central connections)
Why 2G Construction & Energy?
Energy + communication integration experience: OPGW, compatibility with switchgear/transformer and field systems
End-to-end service: project → installation → splicing/termination → OTDR testing → commissioning → maintenance
Standard delivery: labeling, port plan, core management and measurement reports
Field safety and quality: mechanical assembly discipline and documentation approach
Frequently Asked Questions
What is the difference between OPGW and standard fiber? OPGW also acts as a ground wire in the power transmission line and carries the fiber core within the same cable. This allows for better integration with the energy infrastructure.