Design Awards: 2006: Certificate of Merit

Vauxhall Cross Bus Station, London

Vauxhall Cross Bus Station, London

Architect

Arup Associates

Structural Engineer

Arup Associates

Steelwork Contractor

Hawk Engineering & Construction Ltd

Main Contractor

Norwest Holst Ltd

Client

Transport for London

Design Principles

The bus station has been realised as a 200m long, 12m wide, undulating stainless steel ‘ribbon’, which rises as a ‘superlong’ cantilever at its northern nodal end. The development of this as an idea is a functional response to the aspirations and constraints of the brief and the site conditions.

The undulations along the length of the canopy reflect the frequency of bus stands. Each dip of the canopy provides a seating refuge and raking support for the canopy above, which rises over the height of double-decker buses. The folds in the layered ribbon also echo London’s iconic bus and Tube route maps, dating back to the 1930s. The open canopy, rather than an enclosed building, offers free and safe access through permeability and visibility, not obstruction. The emphasis along the concourse is on movement rather than occupation. Equally, the undulating structure has minimal contact with the ground and potential obstructions, remaining from the former highway use which included a significant presence of buried mains services and sewers.

The principal intermodal circulation and the key operational accommodation are at the canopy’s northern end, the accommodation structure being used as a springing point to launch the ribbon’s dramatic elevating twin cantilevers. These over-sail the circulation area and underground obstructions, and project over the most prominent vista of the site to demark the interchange location.

The cantilevers combine their urban role with a functional purpose. The arms are at a 20° inclination facing south and covered with a photovoltaic array to generate power for the building operation, and to actively display the application of the Mayor’s Energy Strategy policies to a new public building. By day, the ribbon allows daylight to enter throughout the circulation area and displays itself in its bold choice of material and sculptural form. By night it becomes an animated floodlit beacon, offering both visual excitement and a well-lit safe environment.

Steel Structure and Fabric

Steel construction was the obvious choice as it offered off site prefabrication of components and convenient erection of modules within the confines of the ‘island’ site. Stainless steel cladding was selected as the most appropriate material to deal with the exposed conditions and durability requirements. Steel is also fully sustainable as it offers end of life recyclability.

Judges’ Comment

s:

This important, but modest, scheme develops an iconic structure which has helped to regenerate a rather forbidding urban traffic junction.

The bus station elegantly gathers together all the elements of public transport – control room, shelter, wayfinding, seating, lighting, etc., within an overall umbrella surface which weaves its way overhead. The steelwork and cladding are relatively straightforward but effective, and the detailing at street level is rugged.

Particularly interesting is that the shape of the roof reflects the graphic of the bus route map.

South East Essex College, Southend-on-Sea

South East Essex College, Southend-on-Sea

Architect

KSS Design Group Ltd

Structural Engineer

Adams Kara Taylor Ltd

Steelwork Contractor

DGT Steel & Cladding Ltd and William Hare Ltd

Main Contractor

Laing O’Rourke

Client

South East Essex College

The new Campus Building for South East Essex College of Art and Technology demonstrates the many benefits that steel can bring to a project. In this building steelwork was used to build an economic, quick and imaginative building exploiting the strength and flexibility of structural steel. It was used to produce a quick, economic frame, a very light and dramatic atrium and dealt with the complex forms of the pod and the dining decks.

When the SEEC decided to relocate within Southend it was keen to exploit the opportunity to expand on its open teaching techniques. The building achieved this through the use of longspan precast planks which were supported on a steelwork frame. This solution allowed column areas of 14.5m x 30m to be formed. The project was procured as a design and build project and AKT worked with the main contractor Laing O’Rourke to develop a steel framed solution that achieved the aspirations of the College whilst satisfying the demanding programme.

A large lean-to atrium structure clad in ETFE standing 36m high and with a maximum span of 34m was formed using tied arches to produce a dramatic airy structure. Within the atrium is a bright red pod which houses a 250 seat lecture theatre. The pod was formed by using a number of steel frames to achieve the complex geometry. A sprayed concrete cladding was applied to the frame to dramatic effect. Also within the atrium us two levels of dining decks. These mushroom like forms were achieved by using cantilevered steel frames stabilised at the head by a concrete diaphragm.

Judges’ Comment

s:

This unusual structure has added great value to the process of consolidating the college from three sites onto one central location.

The main building is L-shaped, and houses teaching and administration functions. In the angle of the block, the team have created a large, light atrium by the use of slender arches with glazing and ETFE pillows on the roof. The space covers galleries at various levels of the college, as well as “mushrooms” used for meeting and refreshment areas.

The quality of this space has had the beneficial effect of greatly increasing the number of applications from students to join the college and share in the excitement of the new environment.

Bullring Spiral Café, Birmingham

Bullring Spiral Cafe Birmingham

Architect

Marks Barfield

Structural Engineer

Price & Myers 3D Engineering

Steelwork Contractor

Sheetfabs Ltd

Main Contractor

Thomas Vale Construction

Client

Birmingham Alliance

The brief for the Spiral Café was to design a small café for St Martin’s Square, the main public space in the £500m Bullring development in Birmingham’s city centre. The purpose of this café was to create a landmark structure, which would be part sculpture and part revenue generator, while at the same time helping to animate the terraces of the hard landscape in which it sits.

The form of the café is derived from sweeping a Fibonacci spiral to create a shell-like canopy. The structure is contained between the inner and outer curved surfaces of the canopy; it both supports the cantilevering roof and provides accurate formwork from which the rest of the construction can take its shape.

The eight structural ribs are arranged radially in plan and each tilts up relative to its neighbour to create the shell-like form. A series of CHSs are set diagonally between the ribs; together they act as a cantilevering shell structure. The ribs are supported at points under the roof of the servery and at the roof level of the rear annexe. Further stiffness is generated by the CHS braces between the ribs, which together act as a cantilevered truss supported at the outer tips of the first three ribs.

To simplify fabrication as much as possible, the structure was made from mild-steel plate ribs cut on a computercontrolled plasma cutting machine. This meant that the form of the building could be manufactured easily, with a number of curved ribs defining its shape. Obviously threedimensional modelling was critical to the design. A product design program was used to develop a parametric threedimensional model. The program was used to model all structural elements and many architectural elements, such as cladding profiles and glazing interfaces. As part of the design process, the architect and the structural engineer worked together on the same three-dimensional model, taking sections and profiles from it to develop further details that were not modelled three-dimensionally.

Drawings generated from the three-dimensional model included a set of true plans of each component. This allowed the steelwork contractor to take the profiles and add additional information, such as bolt holes and splice locations, before cutting the metal. A very high degree of fabrication accuracy was achieved in this way. The level of accuracy in the steelwork allowed us to use the frame as a building-wide template for production for other information later in the programme. Elements such as capping pieces could be designed on the threedimensional model with full confidence that they could fit to what was on site.

Judges’ Comment

s:

The constantly varying curved envelope of this small building provides a fascinating sculptural landmark, which sits well in this major city-centre retail area.

The cantilevered structural form, based on rigorous geometrical parameters, is ingenious. Its execution and reflects a high degree of cooperation between the team. The finished structure was achieved by the skill of the steelwork contractor who made a full trial assembly in his shop, and incorporated sufficient bolted connections to enable the dismantling, transport and final re-assembly on site.

This small “gem” is a testament to craftsmanship in steel.