Samaya Group Completes the Al-Jawf 380 kV Transmission Line

Samaya Group Company Ltd. built the Al-Jawf 380 kV double-circuit overhead transmission line for Saudi Arabia’s Ministry of Energy under an engineering, procurement and construction contract, beginning in August 2021 and completing in September 2023. The line runs approximately 107 kilometres across 279 tower positions in the Tabarjal area of the Al-Jawf region.

The Al-Jawf transmission project was built across 279 tower positions spread over approximately 107 kilometres.

Each location had to be surveyed, reached and prepared before construction could move forward. Foundations came first, followed by the steel structures, conductors, earthwire, fibre-optic systems and protection equipment needed to turn a series of individual sites into one operating transmission line.

The contract the Ministry of Energy awarded

The Ministry of Energy issued its letter of award on 1 August 2021, and the contract took effect on 12 August. It covered engineering, procurement and construction in full: detailed design, supply and transportation of materials, civil works, tower manufacture and erection, conductor tensioning, OPGW and fibre-optic installation, protection and communication systems, testing, and connection to the national grid.

A single contractor carrying that whole chain is what allows scopes as different as topographical survey and fibre-optic commissioning to appear against one name.

Establishing the route across Al-Jawf

A transmission line begins with the route. Before any tower can be erected, engineers must determine where the line should pass, where each structure should stand and how construction teams will reach the individual sites.

For the Al-Jawf 380 kV transmission project, that required detailed engineering, topographical surveying and route planning across the Tabarjal area. The alignment had to account for ground conditions, changes in direction, existing roads and services, electrical clearances and the practical movement of crews, materials and heavy equipment.

These early decisions shaped almost every stage that followed. A straighter section could use a suspension tower. A change in direction required a stronger angle structure capable of resisting additional mechanical forces. Ground conditions influenced the foundation design, while access determined whether excavation equipment, concrete vehicles, cranes and tower components could reach the site.

By the time construction began, the 107-kilometre corridor had already been divided into hundreds of individual engineering and logistical decisions.

Distance was part of the engineering problem

The Al-Jawf line was not built from one central construction site. Work progressed across several locations at the same time.

At one point along the route, crews could be preparing a foundation. Farther ahead, another team might be assembling a tower. On a completed section, conductor stringing could already be under way.

That created a strict sequence. Access had to be available before excavation could begin. Foundations had to be completed and sufficiently cured before tower erection. A continuous section of structures had to be ready before conductors could be installed through it. Testing could only begin after the electrical, communication and protection systems had been completed.

On a project extending more than 100 kilometres, a delay rarely remains isolated. A late foundation affects tower erection. One incomplete tower can interrupt work across several spans. A delayed crossing can hold up conductor installation and testing across an entire section.

Keeping the route moving therefore depended on coordination as much as construction.

What supported the 279 towers

The towers are the most visible part of the line, but their performance depends on the work beneath them.

Each structure required excavation, reinforcement, concrete and accurately positioned tower-base components. Those foundations had to carry the weight of the steelwork while resisting the forces transferred through the conductors.

The requirements were not identical at every location. A suspension tower on a straight section experiences different loads from an angle or terminal structure. Foundation design had to respond to the tower type, the conductor forces and the conditions at the site.

Accuracy was essential. Small errors at foundation level become more difficult to correct as the steel structure rises. The base positions therefore had to be surveyed and checked before erection could proceed.

Building the Al-Jawf tower corridor

The 279 towers formed the physical route of the project, and different structures were used for different parts of the alignment.

Suspension towers carried the conductors through straighter sections of the route. Angle towers were used where the line changed direction and the structures had to resist the pull of conductors approaching from different sides. Terminal or dead-end towers anchored the conductor system at the ends of the line and at other positions where greater mechanical restraint was needed.

Together, these structures allowed the line to follow the approved alignment while maintaining the clearances and stability required for a 380 kV system.

As more towers were completed and inspected, the project gradually changed from a series of separate construction sites into a continuous transmission corridor.

Installing the conductor system

The Al-Jawf line carries two high-voltage electrical circuits along the same route. Conductors were installed across successive tower spans under controlled tension, and their final position had to meet design requirements for sag, clearance and mechanical performance.

The conductor system also relied on thousands of smaller components:

• insulator assemblies

• conductor clamps

• connection fittings

• spacers

• vibration-control equipment

• earthing systems

• lightning-protection components

Insulators support the conductors while separating the live electrical system from the steel towers. Spacers maintain the required arrangement between bundled conductors. Vibration dampers reduce repeated wind-driven movement that could damage cables and fittings over time.

Individually, these components are far less visible than the towers. Collectively, they are essential to the line’s reliability.

Fibre-optic communications along the route

The Al-Jawf transmission corridor was built to carry both electricity and operational data.

Optical Ground Wire, commonly known as OPGW, runs above the phase conductors. OPGW is a cable that does two jobs at once: its outer structure performs the shielding role of a conventional earthwire, helping protect the line from direct lightning strikes, while fibre-optic strands inside it carry protection, control and communication data across the network.

These fibre links support:

• system monitoring

• protection signalling

• fault detection

• operational data exchange

• communication between different parts of the grid

A modern high-voltage line must do more than move electricity. It must be monitored, protected and controlled as part of a wider system. The OPGW and associated communications equipment allowed the Al-Jawf line to function as part of Saudi Arabia’s national transmission network rather than as an isolated physical connection.

What Samaya Group delivered

Samaya Group Company Ltd. was responsible for the engineering, procurement and construction of the Al-Jawf 380 kV double-circuit transmission line. Its scope covered:

• detailed engineering

• route and topographical surveys

• material procurement

• civil and foundation works

• tower supply and erection

• conductor and insulator installation

• OPGW and fibre-optic systems

• protection and communication equipment

• testing and commissioning

• final integration with the grid

Delivering that scope required several disciplines to work across the same programme. Surveyors established the route and tower locations. Civil crews prepared access and foundations. Structural teams erected the towers. Electrical specialists installed the conductor system. Telecommunications engineers completed the fibre and protection links. Quality, safety and commissioning teams verified the completed work.

Each group delivered a different part of the project, but the line could only enter service when those parts operated together.

Testing and grid integration

Completing the physical line was not the final stage. The structures, conductors, insulators, grounding systems, fibre links and protection equipment all had to be inspected and tested before the system could enter operation.

Mechanical checks confirmed that towers and fittings had been installed correctly. Electrical testing assessed the conductors, insulation and earthing arrangements. Communication and protection testing confirmed that data could move correctly across the route and that the line could operate as part of the wider network.

By September 2023, the 279 tower positions had become one completed 380 kV double-circuit transmission corridor connected to Saudi Arabia’s national electricity network.

Al-Jawf’s place in Saudi Arabia’s energy system

Al-Jawf has become an increasingly important region within Saudi Arabia’s wider energy landscape. The region hosts major generation projects, including the Sakaka solar plant and the Dumat Al-Jandal wind farm, which form part of a broader shift in how electricity is produced across the Kingdom.

Generation, however, is only one side of the system. Electricity must also be moved between power plants, substations and areas of demand, and that requires high-capacity transmission infrastructure capable of carrying large volumes of power over long distances.

The Al-Jawf project added approximately 107 kilometres of 380 kV transmission infrastructure to that wider network. Its role was not limited to the towers and conductors visible along the route; it also included the protection, communication and control systems needed for reliable operation across the national grid.

What the Al-Jawf project demonstrates

The project can be described through a few principal figures: approximately 107 kilometres of route, 279 tower positions, two 380 kV circuits, high-voltage conductors and insulator systems, OPGW and fibre-optic communications, protection and monitoring equipment, and testing, commissioning and grid integration.

Those figures describe the scale, but not the full delivery challenge. The project depended on route selection, access, foundation accuracy, material logistics, tower sequencing, conductor installation and communication-system integration across a widely distributed work front.

Each stage created the conditions required for the next.

The most visible result is the line of towers across Al-Jawf. The more significant result is that 279 separate structures and their supporting systems were completed as one operating part of Saudi Arabia’s high-voltage transmission network.