Littlebrook Substation Replacement

Civil and Structural Works Design and Engineering Specialist Plant and Equipment Ground Improvement and Enabling Works
Sector:
Utilities
Client:
National Grid
Main Contractor:
Balfour Beatty Utility Solutions Ltd
Location:
Dartford, Kent

Contact usTo hear about our experiences and how we can help you.

Project Overview

Joseph Gallagher Ltd was engaged to deliver the offline asset replacement of the existing 400kV GIS substation at Littlebrook, located immediately south of the operational facility. The project formed part of National Grid’s major reinvestment programme to enhance asset resilience and ensure long-term network reliability. The works included the construction of a completely new 400kV Gas Insulated Switchgear (GIS) substation comprising nine feeder/transformer bays, two bus section bays and one bus coupler bay, alongside a full decommissioning of the existing substation. All activities were delivered in line with National Grid’s stringent technical specifications and operational requirements.

Scope of Works

The project involved the full delivery of civil and structural works required to support the installation and commissioning of the new GIS equipment, including:

  • Groundworks: Excavations, trenching, duct installation and drainage works
  • Cable Troughs: Installation and formation to support HV cable routing
  • Reinforced Concrete Works: Construction of bases, plinths, groundbearing slabs and foundations
  • Waterproofing of all substation-critical structures
  • Installation of Holding Down Bolts for steel frame structures
  • Horizontal Directional Drilling & Open-Cut Works for service routes
  • External Works to complete access, drainage and structural interfaces
  • JGL-owned specialist plant and equipment used throughout the programme

All permanent works were designed and delivered to meet National Grid’s technical standards, ensuring full compliance and long-term operational performance.

Services Provided

Joseph Gallagher delivered a comprehensive civil engineering package, including:

  • Design of temporary works
  • Supervision, labour, plant and equipment
  • Excavation of bases and formation levels
  • Pile cropping
  • Reinforcement, formwork, and concrete placement
  • Installation of drainage systems, ducts and cable troughs
  • Waterproofing of key assets
  • Full implementation of temporary and permanent works controls

Outcome

The new Littlebrook 400kV GIS substation was successfully constructed and handed over to the client within the agreed programme period. The project enabled National Grid to replace ageing infrastructure with a modern, resilient GIS system, enhancing reliability and ensuring future capacity for the region’s electricity network.

Joseph Gallagher’s integrated delivery approach, specialist plant, and experienced workforce ensured high-quality, safe and efficient execution across all phases of the programme.

Joseph Gallagher Ltd at Littlebrook Substation Replacement Project
Joseph Gallagher Ltd works at Littlebrook Substation Replacement Project
Joseph Gallagher Ltd works at Littlebrook Substation Project
JGL works at Littlebrook Substation Project

Contact us

To hear about our experiences and how we can help you.

Explore related content

Civil and Structural Works

250620 JGL Finham 604

Services

Specialists in civil and structural works, delivering safe, precise construction, reinforced concrete, steel structures, and infrastructure solutions.

Design and Engineering

Services

Experts in specialist plant and equipment providing safe deployment, operation, and maintenance of advanced machinery for complex infrastructure works

Specialist Plant and Equipment

Specialist Plant and Equipment

Services

SPA and NRC are experts in lifting and plant solutions, providing safe, precise deployment, operation and maintenance of advanced machinery.

Ground Improvement and Enabling Works

Services

Specialists in ground improvement and enabling works, delivering safe site preparation, remediation, utilities, drainage and construction readiness.