Projects

Biggleswade 400kV Substation For Omexom.

Overview

Location

Biggleswade

Value

£13.5m

Status

Ongoing

Client

The Challenge.

In Q1 of 2023, we were appointed by Omexom UK as the principal civils contractor for the construction of a new 400kV substation in Biggleswade, a critical infrastructure project delivered on behalf of National Grid.

This new substation forms part of a £40 million investment into the East Anglian energy network, enhancing power capacity and enabling future housing and business developments in the area.

Project Objectives

Deliver enabling civil infrastructure for a new 400/132kV substation
Support the installation of two 178-tonne Supergrid Transformers (SGTs)
Ensure full compliance with NGTS (National Grid Technical Specifications)
Enable timely progress to key outage and commissioning dates

Our Solution.

Our team carried out a wide range of complex and critical civil engineering activities, including:

Foundations & Structural Works

Installation of 1300m3 of concrete and steel reinforcement cages
Construction of reinforced concrete slabs for water tanks, battery rooms, LVAC rooms, and communications rooms
Formation of amenities foundation bases
Grouting of 145 precast columns

Mechanical & Utilities Installation

Installation of a new high-pressure water main
Installation of underground oil draw-off and carrier pipes

Surface & Finishing Works

Placement of 3000 tonnes of chippings across site roads and yards
Application of 140 tonnes of construction screed for the SGT bunds
Preparation of 150,000m2 of ground for aggregation and seeding
Installation of 18 lighting column bases, ducting, and earthing

Key Milestones

February 2024: Successfully delivered and placed the two Supergrid Transformers (SGTs) onto newly completed bunds
Navigated one of the wettest Februarys on record, maintaining programme integrity and safety
Enabled Omexom UK to progress with steel erection, busbar installations, and auxiliary works

Project Highlights

Strong collaboration with Omexom UK, with whom we have delivered multiple projects across the UK
High compliance with National Grid’s technical standards and safety protocols
Delivery under challenging weather conditions and tight milestones
Enabling key infrastructure to support the long-term growth of Biggleswade and
surrounding regions

The Result.

The Biggleswade 400kV substation project demonstrates our capacity to deliver high- specification civil infrastructure under tight timeframes and in challenging environments. As energy infrastructure continues to evolve, we are proud to play a role in strengthening the UK’s power network for the future.

Through close collaboration, targeted workforce upskilling, and robust environmental controls, ACS delivered a critical National Grid extension project within a highly sensitive environment—reinforcing our reputation for safe, high-performance delivery in the energy sector.