Mainline’s technical knowledge and civil expertise is extensive and enables us to deliver all associated civil works relevant to our power, water, telecoms and energy projects. We have an extensive track record of safe and successful delivery of major long-term frameworks, with likes of ESB Networks, ESN Telecoms and Irish Water.

Our civil services include:

  • Underground networks including chamber, pipework and associated fittings
  • Installation of ducting
  • Installation of earthing
  • Installation of direct bury cables
  • Installation of grid connections from windfarms
  • Construction of substation buildings and compounds
  • Construction of windfarm roads
  • Construction of bunded transformer bases
  • Complete compound civil works and construction of buildings and relay rooms
  • Installation of line cubicle bases, ducting, surfacing of compounds and erection of compound fencing and support structures
  • The provision and uplift of access networks including cabling, poling and associated civil works
  • Construction transformer/arc suppression coil (ASC) bunds including blast walls
  • Construction of MV/HV switchgear buildings
  • Construction of new blockwork cable ducting

Sample Projects

Mainline is undertaking the trenching, installation, backfill and reinstatement of over 90km of collector cable trench, together with the refurbishment of various internal windfarm roads.

Project Completed: 19th of October 2018

The scope of this project included the supply and installation of a new MV cable to replace a 30 year old MV ring around the Airfield in Dublin Airport between Substation “A” and the West Substation.

The project was broken up into the following three segments. Each leg was to be upgraded on a phased bases in order to minimise disruption to the network. The three segments were as follows:

  • Segment 1- Upgrade MV Cable between Substation A to Substation E
  • Segment 2- Upgrade MV Cable between Substation E to the Maintenance Base Substation
  • Segment 3- Upgrade MV Cables between Maintenance Base Substation to Substation W

Mainline Power completed the following as a part of the project:

Civils Works

  • Provision of Traffic Management during the works.
  • Provision of circa 3.5km trench to facilitate the MV cable installation which were direct buried in grass areas including cable protection and markers, backfilling of trench, landscaping etc.
  • Provision of pit/ducts for entry into each substation including repairing the pavement after the installation.
  • Provision of a duct for road crossings and drainage ditches to facilitate the new MV cable including repairing of the road pavement.
  • At all-times one segment of the MV network was required to be maintained and operational.

Electrical Works

  • Supply and installation of circa 10,000m new MV cables, 3 number singles plus earth in trench, existing/new ducts.
  • Disconnection of existing MV cables from the Ring Main Unit and removal from the ducts. The decommissioned cables were excavated to at least 20m from the entrance point to the Substations and removed to avoid any future confusion.
  • Terminations of new MV cable to Ring Main Unit (6 Sets of 3 Terminations).
  • Test and commission MV cables including a:
  • Soak test.
  • Partial discharge test.
  • Tan Delta measurement.
  • Update drawings with the GPS coordinate locations of the new MV cable.

At all-times one portion of the MV was required to be maintained and operational.

In conjunction with our JV partners J Murphy & Sons, Mainline have completed delivery of meter installations services to Irish Water for two of the eight domestic water metering regions. The two regions, the South West and West, included the installation of over 262,000 domestic water meters (225,000 of which involved civil works), with a combined contract value of circa €100m. Installation of the water meters peaked at over 11,000 / month, with almost 400 Direct and Indirect Staff across Cork, Kerry, Limerick, Tipperary, Clare and Galway.

ESB 38 to 110kV Substation Framework.

In 2022 Mainline began delivering projects on this ESB 38 to 110kV Substation Framework, , which encompasses a broad range of works from G1/G3 connections (New housing and industrial unit connections), Mini Pillar and Magnafix replacement to Live 38-110kv substation maintenance and refurbishment projects. The framework runs for 7 years across the 26 counties.

 ESB Substation Civils Framework

Since 2015 Mainline has delivered civil upgrade works to over 150 ESB Substations.

Mainline completed the Grid Connection Civil works including joint bays.

Mainline completed the excavation, exposure, extension and reinstatement of several of the 24 joint-bays.

Mainline has undertaken numerous projects nationally for ESB Telecoms as part of the ESBT Framework for underground network maintenance & extension. To date we have completed over 15 projects nationwide, involving the construction of underground ducting, access chambers, as well as the installation of fibre optic cable, splicing, termination and testing.

In October 2014, Mainline Group signed the Minor Civils Framework Contract with Irish Water for several Local Authority Regions in the South and West of the country. The Framework included 5 Lots, covering installation and repair of Water and Sewer Pipelines and Connections, as well as Minor Building Works.

Installation of 38 kV / 110kV ducting to facilitate underground all incoming lines to Westside 38kV Substation, and also to prepare for construction of new 110kV Substation. This work included providing a temporary roadway for traffic on the main outer ring road at Westside and reinstatement of the City park and playing pitches after duct work was completed.

38kV Substation, installation of steel 38kV ducting. Approximately 1.5 km’s of this route was through tidal along the Shannon bank while the remaining 2 km’s was urban. Also installed and jointed 3 x 630sq. 38kV cable.