Sparkbrook & Winson Green 132kV Cable Replacement
Bespoke cable design across Birmingham city centre
Major cost and time savings through specialist solutions
Installation strategies that reduced risk to those installing the cables and the general public
A bespoke, specialist city centre cabling design, this 132kV major fluid cable and overhead line (OHL) replacement project covers a distance of nearly 7km to connect the Sparkbrook AIS substation, an OHL tower and the Winson Green substation to the newly constructed Hockley AIS substation. It saw the development of installation strategies and a design that not only optimised the cable route through the city centre, but minimised the risk to those installing the cables and the general public.
BakerHicks developed the design and installation strategy, covering all aspects related to the HV cable works including the routing and associated civil works. The key activities included:
- Design of cable route, system and bridge reinforcement, trench layout and joint bays, pulling tension and installation systems, cable sealing ends and temporary works for the project
- Bonding diagrams with the proposed line diagrams for each route and options
- Verification of Western Power Distribution’s cable supplier’s proposal, including carrying out CymCap studies to verify proposals
- Analysis of cable crossing to review the impact on existing utility services, EMF analysis on bridge footpaths to ensure the field strength at surface level was below 100micro Tesla, and structural analysis of cable sealing support structures and foundations
- Reviewing designs, including risk and CDM reviews to minimise hazards
Running through the city centre the cable route crossed existing highway bridges, cable bridges, culverts, sewers and other utilities with complex concave and convex bends. Our engineers designed a route and installation strategy that optimised the route for the complex city centre path, reducing the number of joint bays by 40% which minimised the impact on the local community and traffic, making it easier to gain consent for the project and providing the client with major cost and programme savings.
An innovative design, our engineers developed a specialised cable pulling plan, with pits and joint bays to assist in increasing the pulling tension through bespoke cable caterpillars. We developed the design and installation strategy that met EMF best practice and minimised risk through implementing a new approach to installation on cable bridges which reduced the amount of human access required. Working with Southampton University we also optimised the special EMF plate across the bridge where the cables were installed, reducing the risk of public exposure to magnetic fields and ensuring a safe installation process.
The project was completed safely and on time, with a process that caused minimum disruption to the local community whilst delivering an effective design on a complex route.