Griffith House Bulk Supply Point
1 / Introduction
As part of an extensive upgrade, London Underground have commissioned a large new substation building to supply power to the improved rolling stock on the Metropolitan, Circle, District and Hammersmith and City Lines. The Bulk Supply Point at Griffith House, a congested central London site, will be home to hundreds of tonnes of transformers designed to improve the connection between the Underground and the National Grid.
Surrounded by live tracks, a major road, a bridge and an occupied building, creating the right structure for this site was vital. To capitalise on the available space, our team selected a sheet piling system for the retaining structure. By using innovative fibre reinforced concrete to provide both the 4 hour fire protection and waterproofing integrity, the need for secondary reinforcement steel was reduced, clearing more space inside the building, speeding up construction and saving the client money.
Operational requirements meant that we had to adhere to an incredibly tight live load deflection limit of 1mm. With five transformers weighing up to 140 tonnes each inside the building, this was no easy task. By using large slabs and beams across all the floors and creating a ‘forest’ of columns in the lower basement, where the switchgears and cables are routed, we were able to achieve this target whilst still making the best use of the available space.
London Underground had already commissioned a Conceptual Design Statement from another consultant when we were appointed for this project. By reviewing and updating this we were able to both improve and ease the construction sequence for the site and retaining structure, resulting in a faster build.
Nestled between Edgware Road station and Chapel Street, the Bulk Supply Point in the west of London is a perfect example of an ingenious solution to a constrained site. When finished, it will provide power to the upgraded tube lines for years to come.
Key facts
- Surrounded by live tracks, a major road, a bridge and an occupied building
- New substation building
Related Disciplines
The Project Details
Client: ABB/ BAM Nuttal Ltd
Buro Happold services: Structural Engineering, Geotechnical Engineering, MEP, Design Management, Happold Physics, Civil Engineering, Acoustics