TRANSMISSION LINE CONSTRUCTION
TRANSMISSION LINE AS A TURNKEY CONTRACT, FROM DESIGN TO FOUNDATIONS
We carry out the structural design, earthworks, and foundations of transmission lines for grid companies, energy producers, and industry. One partner, one point of responsibility, and a schedule that holds.
Anfra contracts power line projects of all sizes, from 400 kV main grid lines to connection lines for wind and solar parks. The scope of delivery is always tailored to the client's needs.
Versatile
Solutions
- Geotechnical investigations and foundation method statements for tower locations
- Structural design of tower foundations and guy anchorages
- Construction of site roads and access routes
- Clearing of the line corridor and earthworks for tower locations
- Excavations, rock blasting, soil replacement and backfilling
- Procurement and installation of precast foundations
- Cast-in-place foundations and slab foundations
- Rock anchoring and guy foundations
- Piled foundations for soils with low bearing capacity
- Installation of grounding systems
- Cable trenches and earthworks for cable routes
- Site finishing and landscaping
Räätälöity VOIMALINJArakentaminen
Transmission lines transport electricity from generation to consumption. As wind power, solar power, and energy storage increase, new transmission lines are needed for both the main grid and connections to production areas. Every tower stands on a foundation, and it is precisely the quality of these foundations that determines whether the line will withstand decades of wind, ice, and ground frost.
Anfra executes the structural design, earthworks, and foundations for transmission lines under one roof. Our designers and site personnel speak the same language, ensuring that the plans are constructible and modifications are resolved quickly. We can act as the main contractor or as a subcontractor for a transmission line contractor.
STRUCTURAL DESIGN OF TRANSMISSION LINES
Our own In-House Engineering Department designs the foundations for transmission line towers for all voltage levels, from 400 kV and 220 kV main grid lines to 110 kV regional grid and industrial lines. Our team consists of 15 structural designers with FISE qualifications in the most demanding classes for concrete and steel structures.
We design each tower location on a site-specific basis, relying on geotechnical investigations. Loads, soil conditions, ground frost, and groundwater determine whether a precast foundation, cast-in-place concrete, rock anchoring, or piling is selected. A correctly dimensioned foundation is safe and cost-effective, eliminating the need for guesswork on site.
SCOPE OF DESIGN
- Dimensioning of tower and guy foundations
- Foundation method statements and geotechnical investigation programs
- Design of rock anchoring and piling
- Standard design and prefabrication detailing for precast foundations
- Structural integration of grounding systems
- Building Information Modeling (BIM) using Tekla Structures software and IFC deliveries
Transmission line earthworks
Earthworks for transmission lines often begin far from existing roads. We construct site roads and access routes to tower locations, clear the line corridor, and carry out excavations, rock blasting, and soil replacement for the tower sites. With our own equipment, we are able to react quickly and keep work ongoing at multiple tower locations simultaneously
The Finnish terrain can vary from bedrock to swamp within a distance of just a few kilometers. We plan the work sequence so that soft soil sites are executed when the ground is frozen, and load-bearing sections during the frost-free season. This ensures that the equipment moves safely and the soil is preserved.
Scope of Earthworks
- Site roads, culverts, and load-bearing access routes
- Clearing of the line corridor and stump removal
- Excavations and rock blasting for tower locations
- Soil replacement, backfilling, and compaction
- Cable trenches for underground cable sections
- Grounding trenches
- Finishing, landscaping, and the removal of site roads or leaving them as maintenance roads
TRANSMISSION TOWER FOUNDATIONS
Foundations are Anfra's core competence. We execute foundations for transmission towers and guys for all tower types and soil conditions, either as part of a turnkey contract or as a separate foundation contract.
We select the foundation method according to the conditions at the tower location:
| Foundation Method | When Used |
|---|---|
| Precast foundation | On load-bearing soil; fast installation and consistent quality |
| Cast-in-place foundation | For heavy loads or exceptional tower locations |
| Rock anchoring | When bedrock is close to the surface |
| Piled foundation | Soil is clay, peat, or otherwise has low bearing capacity |
| Guy foundation | For guyed portal towers |
Our experience in concrete construction is reflected in our dimensional accuracy. Anchor bolts and embedments are exactly where they need to be, allowing tower erection to proceed without corrective work. We document the measurements and quality assurance of every foundation in accordance with the client's requirements.
References - transmissionlines
AURORA LINE
Anfra toteutti Fingridin ja SVK:n Aurora Line -voimalinjahankkeelle paikallavaluperustuksia n.
Frequently asked about transmissionline construction - FAQ
What does a transmission line project involve?
A transmission line project typically progresses from route planning to geotechnical investigations, structural design, earthworks, foundations, tower erection, and conductor stringing. Anfra is responsible for the structural and civil engineering scope of the project—namely structural design, earthworks, and foundations. For the client, this means a single point of responsibility throughout the entire earthworks and foundation phase.
What is the difference between a power line and a transmission line?
None. Transmission line is the official industry term, whereas power line is colloquial. Both refer to an overhead line where electricity is transmitted through conductors supported by towers.
Can you execute only the transmission tower foundations?
Yes. We often construct foundations as a subcontract for transmission line contractors and main contractors. We can also provide foundation design only.
How is the foundation method selected?
The foundation method is selected on a site-specific basis based on geotechnical investigations, tower loads, and the surrounding environment. On load-bearing soils, a precast foundation is often the fastest option. Rock anchoring is used on bedrock, and piled foundations are used in soils with low bearing capacity.
Do you construct connection lines for wind and solar parks?
Yes. New generation sites require a connection line to a substation or the main grid. Within the same project, we can carry out the civil engineering works for both the substation and the connection line, which clarifies the schedule and interfaces.
Can transmission line foundations be built in winter?
Yes, and it is often even advisable. Frozen ground bears heavy equipment on soft terrain. For concrete works, we take care of cold weather concreting requirements, such as heating and thermal protection.
Do you have experience with Fingrid’s requirements?
Yes. We have operated as a foundation contractor in the transmission system operator’s substation projects and are well-acquainted with their strict quality and safety requirements. In Sweden, we operate in projects for Svenska kraftnät and major grid companies.
How do you ensure occupational safety on transmission line sites?
Our goal is zero accidents. We prepare a site-specific safety plan for every project, and our personnel hold all required qualifications, such as electrical safety and occupational safety cards. Working in the vicinity of energized lines is always planned in collaboration with the grid operator.
Transmission line construction project at hands?
Tell us about your plans – we will determine the optimal scope of delivery, the most efficient solutions, and a reliable schedule for your project.
We operate throughout Finland and Sweden.
Certified, financially stable, and award-winning
Anfra's activities are based on ISO 9001 -quality system, ISO 45001 -an occupational health and safety system; and ISO 14001 environmental management system.
