Prefabrication

Using pre-fabricated modular components to build technically complex infrastructure

Putting innovation at the heart of Thameslink Programme

Thameslink Programme placed innovation at its heart throughout its lifespan, from design through construction, to improve the experience for the community, client (Network Rail) and the end user – the passengers.

A key example of innovation deployed by the project was the use of pre-fabricated modular components to build technically complex infrastructure. This was used across the London Bridge redevelopment project, including parts of the platforms, the platform canopies and large facades on either side of the station. It was also used at the Bermondsey Dive Under, a grade-separated junction build by the Thameslink Programme to untangle the tracks to the east of London Bridge.

Components were built offsite and then brought onsite for the final installation, because the projects did not have the physical space to do some of the construction activity. We also worked very closely with our supply chain to make sure we had the right flow of people.

London Bridge remained open throughout the redeveloment, while passenger numbers continued to rise, posing the challenge of tight time constraints as well as working within a limited space. While it would have been cheaper and quicker to rebuild the station and surrounding railway with both completely closed, this was unrealistic outside of extended Bank Holiday weekends and Christmas periods. Consequently, the project had to deploy innovative techniques to stay within strict time boundaries while working within the tight space of central London.

The use of pre-fabricated modular components was challenging due to the requirement to work around the existing operational assets, but by using bespoke designs and learning throughout the programme, it was successful. The platforms and canopies in particular were able to accommodate the twist and turns of track alignment that channel through the fourth busiest station in the UK, while the pre-fabricated facades have been noted to exceed the aesthetic requirements to fit in with the area.

Case Studies

Concourse & Bridge Decks Prefabrication: London Bridge Station

London Bridge station's innovative use of prefabrication saw it win a Structural Steel Award Prize for 2018. This case study looks at the prefabrication of the station bridge decks, installation of the decks and canopies plus the related challenges and achievements.

Mock Up: London Bridge Station

James Elford, London Bridge Project Director, Costain discusses the benefits of using scale or full size models to demonstrate the design, aesthetics and materials used on elements of the project.

Structural Steel – Blackfriars

During the early construction phase at Blackfriars station, complex temporary steel walkways and staircases were installed to assist with the diverted passenger flows.

Structural Steel – Farringdon

The existing arched Victorian roof was to be extended at Farringdon station. The new structural steel section had to be built over the live railway lines which needed to be kept running.

Structural Steel – London Bridge

With steelwork being on the London Bridge project’s critical path, any problems encountered by Bourne Group had a knock-on impact to the rest of the programme, so it was important to keep whole project team happy.

Offsite Manufacturing of Roof Canopies

This case study looks at how each steel roof canopy was manufactured and partially assembled offsite. Final finishing was carried out on site at ground level and then lifted into place in a pre-practiced method.