Oliver Tyler, Director at WilkinsonEyre, has led the design of Liverpool Street Elizabeth Line through several iterations since 1992. Here he describes the design journey and the constraints faced by the team on this slowly evolving project which finally opened in May 2022.
Crossrail, opening as the Elizabeth Line, is the most ambitious infrastructure project in London of the 21st Century, affording accessible, efficient and sustainable transport for generations to come. WilkinsonEyre has been involved with the development of the Crossrail station at Liverpool Street since the initial phase of the project dating back to 1992 and were re-engaged when the project started up again in 2002. Our appointment has taken the scheme through successive design stages, including safeguarding the design intent on behalf of the client during construction.
The scope of the station as it stands now was developed through the middle of the 2000s. The vision was very much defined by the significant constraints faced at this point on the line, tighter than those faced by the other stations in the central section. Planning Liverpool Street was one of line’s most complex challenges, there is a lot of existing infrastructure below the City of London around here, including Northern and Circle Underground lines, the Post Office railway, culverted rivers, sewers, and pile foundations to buildings. The task of threading new infrastructure through it is akin to advanced surgery. Where possible, the new running tunnels and access points avoid running under existing buildings, the route taken by the line at this point can be traced from Moorfields/Moor Place, under the landscaped part of Finsbury Circus and down Liverpool Street to interchange with the booking hall of the existing Underground station.
At Broadgate, we have a ticket hall just beneath street level, and at Moorgate another ticket hall at ground level above the Metropolitan/Circle lines and beneath an over-site development, also designed by WilkinsonEyre. The challenge at both ends was to shape a series of transitional spaces that people want to use, can move through intuitively, feel safe, but also get a sense of visual interest and excitement on the journey down to the platforms.
The sequence of spaces determined by these constraints resulted in quite low, rectilinear ticket halls, moving into the larger volumes of the escalator boxes, followed by the network of tunnels accessing the platforms 30m below ground. Getting daylight into underground stations is always a challenge but it has been achieved here with a glazed canopy over the Broadgate entrance escalator box. Adding value and improving the passenger experience was an important consideration; this includes revising the location and design of the Moorgate-end of the station, which has changed from a stand-alone design to a fully integrated station with an improved interface with the existing LU Moorgate station. This approach made it possible to keep the existing ticket hall operational during construction. The final design has a strong street identity with a blue-glazed portal, illuminated at night, proclaiming the presence of the Elizabeth Line beneath.
The importance of this project meant that we were keen to give both ends of the station, though separated by over 400m, a unified architectural identity, one distinct from other stations on the line.
Our solution was to provide a “folded” concrete soffit formed from fine precast concrete elements that span both ticket halls and the upper part of the escalator boxes. These elements have ribbed detail that gives an appearance of movement to the ceilings and walls, and create pleasing effects of light and shade, helped by the concrete mix of reconstituted Portland stone with mica to give some sparkle to the appearance. We did a lot of testing with mock-ups in different lighting to achieve the desired effect; the outcome is - we hope - a crisp interpretation of the City’s historic use of Portland stone to enhance a high-traffic station environment, one that will require a minimum of maintenance over its projected long life. The flooring is a reconstituted stone with a high level of granite in it, known as granazzo, in a shade designed to reflect as much light as possible while remaining a durable and practical solution.
The deep escalator boxes presented our opportunity to be as architecturally expressive as possible. We wanted to evoke the feeling of walking into the nave of a Mediaeval cathedral, with a similar scale and volume, an experience that would be particularly striking when emerging from the tunnels below into this lofty space. We worked hard to avoid having horizontal props across this area, so they could be enjoyed as uninterrupted volumes, with the folded soffit pattern running in from the ticket halls, and a complementary pattern to the wall cladding panels suggestive of geological strata as you descend to the low level platfoms. Throughout there is a strong geometry which adds a richness to the passenger experience.
At platform level, the subsurface Elizabeth Line stations share a common language of glass reinforced concrete tunnel lining system designed by Grimshaw. Because this is a very fluid but sturdy material, it has been possible to express the flow and curvature of the access tunnels (adits) and improve passenger flow and visibility round corners. The wayfinding totems, lighting, seating and platform edge enclosures also form part of this line-wide language, which gives the Elizabeth Line the elegant uniformity of earlier periods of network expansion, such as the 1960s Victoria Line and the 1930s Piccadilly Line extensions by Charles Holden.
The arrival of the Elizabeth Line has had a ripple effect on the development of the surrounding area. WilkinsonEyre has explored and highlighted the opportunity for commercial development associated with Liverpool Street Station as part of the early feasibility studies when different sites were explored. In subsequent station design development, safeguarding and spaceproofing for Oversite Development (OSD) interfaces have been included within the station design to protect the commercial value of future OSDs. These interventions include the integration of a “super-column” to found the building above at Moorfields. This forward thinking has resulted in the realisation of a commercial development, also designed by WilkinsonEyre, adopted as the new headquarters of Deutsche Bank and completing by 2023.
Our involvement in both these projects means we have coordinated the interfaces between the two designs to maximise the synergy between them to their mutual benefit and enhancement.
The public realm design at both ends has given a much greater priority to pedestrians, and traffic has been excluded from both Liverpool Street and Moorfields around the station entrances. Soft planting and seating were dropped during the design development in anticipation of high passenger flows, but the flexibility exists to accommodate changing urban trends. A public art programme will see two new installations at either entrance – a bronze sculpture by Conrad Shawcross at the western entrance and the first permanent UK installation by Yayoi Kusama in front of the Liverpool Street entrance. The glass entrance on Broadgate glows like a lantern after dark, serving as a wayfinder and landmark for the enormous station beneath. I’m looking forward to finding out how our designs to improve the passenger experience work out in practice and how users engage with this major new addition to London’s infrastructure.
Oliver Tyler, Director at WilkinsonEyre