Mainline is a leading engineering solutions provider

Operating in Ireland, the UK and Scandinavia, Mainline provides a wide range of services from the Design & Build of Sub-stations, to construction of Airside Aviation Infrastructure, to Turn-key Wind & Solar Energy Solutions.

Mainline has a robust corporate management structure, underpinned by our ISO 45001, 14001, 9001 and cyber essentials accreditations as well as our Platinum Member Deloitte Best Managed Company status. We are also delighted to have been selected as an EY Entrepreneur of the Year Finalist 2022.

About Us

Delivering Internationally

Ongoing &
Recent Projects


Mainline are currently delivering a significant second Wind Farm project in Northern Sweden, Phases 1 & 2 of Markbygden Wind Farm, part of the overall 1,002 Turbine Markbygden cluster, close to Pitea.

Scope of work includes:

  • Full Electrical Design for Markbygden Wind Farm (Phases 1-3) for a total of 137 wind turbines c/w 680km of 36kV collector system.
  • Currently delivering Phases 1 & 2 EBoP works for 69 wind turbines comprising
  • Over 350km of MV cable,
  • Over 90km of associated Earthing conductor
  • Over 90km of telecoms fibre
  • Installation of cable jointing, terminations and testing/commissioning of the 36kV collector system
  • Wind turbine earthing installation for 69 wind turbines
  • Design, supply, installation and commissioning of 9 external Switching Stations all fitted with 36kV switchgear, protection and LV requirements.
  • Managing, liaising and coordinating on site activities

We successfully delivering the 73 Wind Turbine Electrical Balance of Plant (EBoP) for Hästkullen Wind Farm, in the Nysäter wind park, close to Sundsvall. The scope of the project included:

  • Engineering and construction (design, optimisation and build) of the 36kV collector cable to 73 wind turbines.
  • Over 95 km of associated civil works, trenching and backfill, through a variety of terrains from wetlands to rock, including a number of directional drills.
  • Over 95 km of associated earthing conductor works.
  • Over 155km of fibre telecommunication works.
  • Installation, cable jointing, testing, commissioning and energisation of almost 455 linear km of 36kV cable.
  • Various additional civil works, including the construction of an access road.

The new North Runway project in Dublin Airport is the most substantial airfield project in Ireland for a long time, and upon completion it will become a vital piece of national infrastructure, significantly increasing the capacity of Dublin Airport. Mainline are the Lead Electrical Contractor on this large scale Aviation project, and our scope includes the supply and installation of the following:

  • Over 340km of primary cable in ducts adjacent to the runway
  • Over 135km of secondary cable (feeding each light)
  • Termination of primary and secondary cables
  • Over 2,500 Transformers in manholes
  • Over 28km of Fibre Optic Cable
  • Over 27km of MV Cable
  • Over 11km of 50 Pair Copper Telecoms Cable
  • Over 5 km of Earth Cable
  • Over 100 Runway/Taxiway signs
  • Over 1,800 shallow bases for Airfield Ground Lights
  • Over 2,200 aviation lights including:
    • Runway lights
    • Taxiway lights
    • PAPI lights
    • Approach lights
  • Complete fit-out of 2 substations including:
    • Mechanical & Electrical fit-out
    • HV Switchgear
    • Circuit breakers
    • HV Transformers
    • Constant Current Regulators (CCRs)
    • Back-up generators
    • Distribution Boards
    • Fire Suppression Systems
    • Building Management Systems
    • UPS’s
    • Lighting protection Systems
    • Security Systems

Mainline completed the EBoP (Electrical Balance of Plant) & CBoP (Civil) works in 2019, the scope of the project included:

  • EBoP Substation Design and Build / Fit Out (IPP and ESBN stations)
  • Wind Farm and Grid Connection MV/HV Cables (Installation/Jointing/Testing)
  • Wind Farm and Grid Connection Fiber (Installation/Jointing/Testing)
  • Completion of the CBoP Works upon Termination of CBoP Main Contract (due to Examinership of the CBoP Contractor). CBoP Works included significant Substation, Wind Farm, Delivery Route and 38kV Grid Connection works.
  • Managing, liaising, co-ordination commissioning of the Sub-station with the ESB Networks (ESBN).
  • PSCS for all of the above.

Site: Slievecallan Wind Farm (East and West), Glennageer, Co. Clare.

Work Completed: 29 x Turbines Energised following testing and commissioning. Managed HV Safety rules on site for the client to allow for the VLF testing of circuits, access into the Basement of the Turbine for Ongoing maintenance.

Site: Tullahannell Wind Farm, Tullahennell South, Co. Kerry.

Work Completed: 13 x Turbines Energised following testing and commissioning. Managed HV Safety rules on site for the client to allow for the VLF testing of circuits, access into the Basement of the Turbine for Ongoing maintenance.

Mainline has undertaken civil upgrade works to over 100 ESB Substations.

Our Clients