Case Studies

Hawton 132kV Cable Diversions

OCU delivered the diversion of existing 132kV overhead line infrastructure at Hawton, Nottinghamshire, replacing eight spans of overhead line with a new underground cable system.

Mapperley & Gedling Cable Works

OCU delivered the upgrade of ageing 33kV fluid-filled cable circuits between Nottingham East 132kV Substation and the Gedling and Mapperley primary substations, acting as Principal Contractor for the works.

Camblesforth Solar Farm

Camblesforth Solar Farm Ltd is developing a 68MWp solar farm with a co-located 10MW/24MWh battery energy storage system at Camblesforth Hall Farm, Selby, West Yorkshire.

Mauxhall BESS

OCU Group was appointed as Sub-EPC contractor to design, build and commission a new 25MW Battery Energy Storage System (BESS) at Mauxhall Farm, adjacent to a recently commissioned solar PV site near Immingham.

Pitkevey BESS Fife, Scotland

The project covered full BoP works for a 50MW battery storage site in Fife, including access roads, drainage, switchrooms, 33kV cabling, MV transformers, BESS units, and 2km of DNO cabling over sensitive terrain.

Ray Wind Farm 20MW BESS Project

This 20MW Battery Energy Storage System (BESS) project was constructed at Ray Wind Farm approximately 5km south of the village of Otterburn in Northumberland.

Pitkevy 40 MW BESS Project

Our teams delivered the Civil and Electrical works associated with a new 50MW Battery Energy Storage System (BESS).

Jamesfield 49MW BESS Project

Our teams provided the Civil and Electrical works associated with a new 49MW Battery Energy Storage System (BESS).

Ferrybridge 150MW BESS Project

OCU were awarded the contract by Scottish and Southern Energy Renewables Ltd for the Design, Construction, Commissioning and Handover of the 132kV/33kV Electrical Infrastructure and Substation Plant and Control Systems.

Capenhurst 100MW BESS Project

Capenhurst is a 100MW Battery Energy Storage System (BESS) connected to the National Grid (NGET) at 275kV.

Penwortham BESS - Howick Cross

OCU were brought in to take over rectification of the design, finalising construction and completing the energisation of site following the former supplier's liquidation.

Kintore Substation - HDD Installation

OCU delivered a design-and-build HDD solution at Kintore Substation to install new cable ducts for twin 132kV circuits beneath the B977, replacing existing oil-filled cables.

School Hill & Addison Road HDD UTX

OCU delivered complex utility diversion and under-track crossing (UTX) works at School Hill and Addison Road as part of HS2’s Enabling Works Contract in Calvert, Buckinghamshire.

Corran Narrows

OCU delivered a critical 33kV underground cable installation beneath Loch Linnhe to replace ageing seabed cables that had repeatedly faulted due to harsh tidal and geological conditions.

Axford Pipeline Thames Water

OCU was appointed to deliver the Axford Pipeline scheme for Thames Water. The project involved constructing a 17.6km clean water pipeline, building a new booster station at Dorcan.

Orkney-Caithness HVAC 220kV Landfall

OCU Group delivered two 1,200m parallel landfall crossings as part of SSEN’s 220MW high-voltage transmission project linking Finstown in Orkney to Dounreay in Caithness.

Cork Harbour Horizontal Directional Drilling

OCU was contracted to design and install twin 1,025 metre lengths of 500mm Diameter SDR-9 PE100 Foul Main under Cork Harbour using Horizontal Directional Drilling (HDD).

Dee-crossing Connah's Key

OCU was awarded the Dee Crossing contract, located in Connah’s Quay. Our teams designed and installed two 860m-long barrier pipelines under the River Dee using Horizontal Directional Drilling (HDD).

Preseli Pumping Station

OCU delivered the upgrade of pumping and control infrastructure at Preseli Clear Water Pumping Station, which supplies treated water directly into the distribution network.

Tafarnaubach Trunk Main Renewal

OCU delivered the emergency replacement of the Tafarnaubach trunk main after a landslide during Storm Dennis caused failure of a 600mm water main supplying the local network.

Pen Y Ball Pipeline

OCU delivered the construction of a 5.2km clean water pipeline between Lixwm and Pen Y Ball Reservoir in North Wales.

Bredenbury Pressurised Pipeline System

OCU delivered the Bredenbury Pressurised Pipeline System for Dŵr Cymru Welsh Water as part of its Main Network Renewal programme.

Grandstand Road Slip Lining

OCU delivered a distribution mains renewal programme for Dŵr Cymru Welsh Water, installing 9.3 km of new mains following investigations into existing distribution assets.

Brynmoelddu pressurised pipeline system

OCU delivered the Brynmoelddu pressurised pipeline renewal scheme for Dŵr Cymru Welsh Water, replacing an existing asbestos cement main using pipe bursting and installing 1,120 m of MDPE.

Axford Pipeline Thames Water

OCU was appointed to deliver the Axford Pipeline scheme for Thames Water. The project involved constructing a 17.6km clean water pipeline, building a new booster station at Dorcan.

Vyrnwy Aqueduct Modernisation Programme

The Vyrnwy Aqueduct programme involves a major refurbishment of one of United Utilities' oldest and most strategic clean water assets. Phase one, completed in 2024, included cleaning, seal repairs, and new valves on Line 3. The project is scheduled to be finished by 2028.

Customer Focused Framework Yorkshire Water

Yorkshire Water appointed OCU to deliver key works under its Clean and Waste Infrastructure and Customer Focused Infrastructure Frameworks, part of the £650m AMP7 investment programme (2020-2025). Following a strong performance, OCU secured a four-year extension into AMP8.

Water Retaining Structures
(WRS) Framework Affinity Water

Delivering new service reservoirs under the WRS Framework for Affinity Water’s Strategic Supply 2040 Programme, increasing storage capacity and strengthening water supply resilience across Bedfordshire and Hertfordshire.

Network Maintenance Services
United Utilities

Providing specialist network maintenance under Lot 8 of United Utilities’ framework, delivering complex repairs to noncore clean water assets including aqueducts and pipe bridges, with key works such as the multi-year refurbishment of the historic Lake Vyrnwy Aqueduct.

HS2, Old Oak Common
Enabling and Multi Utility Diversion Works

Delivering multiple utility diversion packages at Old Oak Common Station, including water, gas, regulated power and telecoms, enabling construction of the HS2 transport superhub in West London.

HS2 Infrastructure
Enabling and Multi Utility Diversion Works

Delivering utility diversions across water, gas, power and telecoms for a major UK rail project, with our Water and HDD teams applying NIRS, GIRS and WIRS accreditations to complete complex works in constrained environments.

Capital Major / Minor Mechanical and Electrical Frameworks

Delivering clean and wastewater projects as a Capital Alliance Delivery Partner for Welsh Water under AMPs 8 & 9, building on over 15 years of partnership and framework support across pipelines, mechanical and electrical works.

Capital Delivery Pressurised Pipeline Framework Welsh Water

Longstanding delivery partner on Welsh Water’s Pressurised Pipe Framework since 2012, delivering mains rehabilitation, planned and emergency trunk main works, HDD river and rail crossings, and 24/7 support for complex reactive repairs.

Cork Harbour Horizontal Directional Drilling

OCU was contracted to design and install twin 1,025 metre lengths of 500mm Diameter SDR-9 PE100 Foul Main under Cork Harbour using Horizontal Directional Drilling (HDD).

Dee-crossing Connah's Key

OCU was awarded the Dee Crossing contract, located in Connah’s Quay. Our teams designed and installed two 860m-long barrier pipelines under the River Dee using Horizontal Directional Drilling (HDD).

Modular Storm Tanks - SW Water

OCU took on the emergency job of the installation of several modular storm tanks at 3 different live site locations to meet key WINEP dates for SWW compliance to the EA for 2024 in a 12-week window as PC and PD for SWW at their request in Devon.

Jamesfield 49MW BESS Project

Our teams provided the Civil and Electrical works associated with a new 49MW Battery Energy Storage System (BESS).

Humber Cluster Energy Saving Campaign

ABP identified a number of Transformer Assets that are progressing in age and have a considerable number of losses when they are transforming the High Voltage Network down to the localised Low Voltage requirement.

Ferrybridge 150MW BESS Project

OCU were awarded the contract by Scottish and Southern Energy Renewables Ltd for the Design, Construction, Commissioning and Handover of the 132kV/33kV Electrical Infrastructure and Substation Plant and Control Systems.

Capenhurst 100MW BESS Project

Capenhurst is a 100MW Battery Energy Storage System (BESS) connected to the National Grid (NGET) at 275kV.

Penwortham BESS - Howick Cross

OCU were brought in to take over rectification of the design, finalising construction and completing the energisation of site following the former supplier's liquidation.

Braidwood Primary Substation - SP Energy Networks (SPEN)

Delivering a full refurbishment of the 12 MVA primary transformer T2 at Braidwood Primary Substation, Scotland, restoring safe and reliable operation while ensuring full compliance with environmental and operational standards.

Water Retaining Structures
(WRS) Framework Affinity Water

Delivering new service reservoirs under the WRS Framework for Affinity Water’s Strategic Supply 2040 Programme, increasing storage capacity and strengthening water supply resilience across Bedfordshire and Hertfordshire.

Network Maintenance Services
United Utilities

Providing specialist network maintenance under Lot 8 of United Utilities’ framework, delivering complex repairs to noncore clean water assets including aqueducts and pipe bridges, with key works such as the multi-year refurbishment of the historic Lake Vyrnwy Aqueduct.

HS2, Old Oak Common
Enabling and Multi Utility Diversion Works

Delivering multiple utility diversion packages at Old Oak Common Station, including water, gas, regulated power and telecoms, enabling construction of the HS2 transport superhub in West London.

HS2 Infrastructure
Enabling and Multi Utility Diversion Works

Delivering utility diversions across water, gas, power and telecoms for a major UK rail project, with our Water and HDD teams applying NIRS, GIRS and WIRS accreditations to complete complex works in constrained environments.

Capital Major / Minor Mechanical and Electrical Frameworks

Delivering clean and wastewater projects as a Capital Alliance Delivery Partner for Welsh Water under AMPs 8 & 9, building on over 15 years of partnership and framework support across pipelines, mechanical and electrical works.

Capital Delivery Pressurised Pipeline Framework Welsh Water

Longstanding delivery partner on Welsh Water’s Pressurised Pipe Framework since 2012, delivering mains rehabilitation, planned and emergency trunk main works, HDD river and rail crossings, and 24/7 support for complex reactive repairs.

Mill Hill, Longforgen

Upgraded the electrical infrastructure at Mill Hill, Longforgan with new 11kV wood poles, overhead switchgear, and a third conductor to supply a 200kVA transformer, enabling a three-phase connection for new solar and ground source heat pump installations.

Mill Drowndubbs

Upgraded the electrical infrastructure at Mill Drowndubbs with new 11kV wood poles, overhead switchgear, and an additional conductor to provide a three-phase supply and transformer upgrade for an SSEN customer.

Peterhead Substation

Under an NEC3 subcontract, we built a 2000m² GIS Substation, two transformer buildings, a 210m x 150m platform, reinforced structures, improved access, and installed underground cabling with GRP covers.

Neilston Grid Stability Facility

NEC4 Option A contract involved the construction of a 653m² portal frame for a Synchronous Condenser, with 8500m² platform, 1km access road, fencing and earthing - providing robust, secure foundations for long-term operation.

Pitkevey BESS Fife, Scotland

The project covered full BoP works for a 50MW battery storage site in Fife, including access roads, drainage, switchrooms, 33kV cabling, MV transformers, BESS units, and 2km of DNO cabling over sensitive terrain.

Openreach Full Fibre Network Delivery

OCU is delivering a full turnkey Fibre Network Delivery (FND) programme across the south region for Openreach, enabling full fibre connectivity across multiple exchange areas.

Vodafone Fibre Call Out

OCU is contracted by Vodafone to deliver fibre and civils call out services on a 24/7/365 basis throughout England and Wales.

NEOS Fibre Maintenance - UK Wide

OCU holds the repair and maintenance agreement with NEOS throughout England. We provide all fibre associated works including, Highways, PIA, confined spaces, roof top, and overhead cables.

Lumen Fibre Maintenance

OCU is the road network maintenance provider for Lumen. Our teams are responsible for repairs across COLT Neo’s (Lumen’s 500km fibre network) both proactively and reactively.

Peterhead Substation

Under an NEC3 subcontract, we built a 2000m² GIS Substation, two transformer buildings, a 210m x 150m platform, reinforced structures, improved access, and installed underground cabling with GRP covers.

Neilston Grid Stability Facility

NEC4 Option A contract involved the construction of a 653m² portal frame for a Synchronous Condenser, with 8500m² platform, 1km access road, fencing and earthing - providing robust, secure foundations for long-term operation.

Braidwood Primary Substation - SP Energy Networks (SPEN)

Water Retaining Structures(WRS) Framework Affinity Water

Network Maintenance ServicesUnited Utilities

HS2, Old Oak CommonEnabling and Multi Utility Diversion Works

HS2 InfrastructureEnabling and Multi Utility Diversion Works

Capital Major / Minor Mechanical and Electrical Frameworks

Capital Delivery Pressurised Pipeline Framework Welsh Water

Mill Hill, Longforgen

Mill Drowndubbs

Peterhead Substation

Neilston Grid Stability Facility

Pitkevey BESS Fife, Scotland

Braidwood Primary Substation - SP Energy Networks (SPEN)

Water Retaining Structures(WRS) Framework Affinity Water

Network Maintenance ServicesUnited Utilities

HS2, Old Oak CommonEnabling and Multi Utility Diversion Works

HS2 InfrastructureEnabling and Multi Utility Diversion Works

Capital Major / Minor Mechanical and Electrical Frameworks

Capital Delivery Pressurised Pipeline Framework Welsh Water

Mill Hill, Longforgen

Mill Drowndubbs

Peterhead Substation

Neilston Grid Stability Facility

Pitkevey BESS Fife, Scotland

Water Retaining Structures
(WRS) Framework Affinity Water

Network Maintenance Services
United Utilities

HS2, Old Oak Common
Enabling and Multi Utility Diversion Works

HS2 Infrastructure
Enabling and Multi Utility Diversion Works

Water Retaining Structures
(WRS) Framework Affinity Water

Network Maintenance Services
United Utilities

HS2, Old Oak Common
Enabling and Multi Utility Diversion Works

HS2 Infrastructure
Enabling and Multi Utility Diversion Works