Light is integral to architecture; it reveals beauty, function and form. It defines the image, colour and texture of cities, buildings and landscapes. It determines visual boundaries and our understanding of scale. The built environment is designed not only to provide light, but to be experienced in light.

(Anthony Tischhauser, Made of Light, The Art of Architecture and Light, Birkhäuser, 2005)

Since 1980 Nexus, the public transport executive for Tyne and Wear, has commissioned a wide range of artists to make permanent and temporary works designed to enhance passengers’ experience of public transport. Through the Art on Transport programme, Nexus seeks to ensure that the creative skills and imagination of artists are effectively integrated into its facilities and services, transforming spaces into places and reinforcing a unique sense of identity.

In 2004 Nexus started planning to repaint the Queen Elizabeth II Metro Bridge, which spans the Tyne between Newcastle and Gateshead, and a long held ambition to illuminate the bridge was revived. The idea had last been considered in 1998 when the Newcastle Initiative commissioned consultants to determine the feasibility of illuminating the five bridges upstream from the Tyne Bridge. During the intervening years the Millennium, Tyne, High Level and Swing Bridges have all been illuminated whilst the QEII Metro Bridge, highly visible to passengers arriving in Newcastle by train in daytime, remained in darkness at night. In 2005, having already commissioned a number of artists to produce artworks using the medium of artificial light, it was a natural progression for Nexus to engage four selected artists to develop proposals for the bridge. The artists’ brief essentially asked them to consider how to incorporate the use of artificial light to articulate the scale, construction, practical and symbolic functions of the bridge. The scope of their brief also encompassed the possibility for them to propose a new colour scheme for the repainting of the bridge. After review of presentations by the artists Nayan Kulkarni’s proposal, Nocturne, was selected.

Travellers using the Metro between Newcastle and Gateshead experience a dramatic transition between these two major conurbations. The Metro line passes through tunnels on each side of the Tyne, emerging on either side of the Tyne Gorge to be carried high over the river by the QE II Metro Bridge. Construction started in 1976 and the through-truss steel girder construction was built out from each bank, with the two sections meeting on August 1, 1978. The span between the concrete piers is 168 metres, it carries the lines 25 metres above the River Tyne, and the full length of the bridge is 360 metres. Its construction cost £6.16m and at the time it was the longest bridge of its kind in Europe. It was opened by Queen Elizabeth II when Her Majesty officially opened the Metro in November 1981.

The bridge has to be repainted approximately every 15 years, a project that requires 6,000 litres of paint and 45,000 metres of scaffolding. It was last painted in 1990, using the original rather non-descript pale colour, ‘Lakeland Green’, which had apparently been chosen to reduce the visual presence of the bridge.

The ‘Blue Bridge’:The design of the paint scheme followed the same principles as those applied by the artist to the lighting – that as part of an overall artwork the scheme is determined by the form of the bridge itself. Perhaps the most radical step was to paint the dominant structural form in a mid tone blue which unapologetically places the bridge into the sequence of structures which span the Tyne Gorge. This serves to emphasise the scale of the bridge, the sculptural elegance of its concrete piers and the way in which it connects with the north and south banks of the river. Nayan Kulkarni has described how, ‘the three colours (blue, white and dark brown) seek to emphasise the primary shapes and place in shadow, or background, other less important elements. The white areas within the steel trusses have a dual purpose; firstly they create the simple pattern I wanted to expose in the bridge. Secondly they provide a surface onto which subtle colours can be projected at low power.’ The areas painted white also exploit the multiple viewing possibilities for people seeing the bridge, as from certain angles more of the white areas appear to influence peoples’ perception of the bridge.

Nayan Kulkarni’s response to the brief was to conceive a light work totally integrated within the bridge, bringing a new dimension to the structure. In considering how the bridge might determine the form and content of the work Nayan Kulkarni describes how he was, ‘Struck by the way that the very simple geometries that make the bridge work come together to produce very complex patterns and views. These patterns and changing angles in the steelwork created the dynamic lit form.’ The concept for the work also takes into account the natural rhythms of the tide, reflected in the twice daily rise and fall of the river, and its interface with the movement of trains and people travelling across the bridge.

"Cities are living places that are animated by their communities. They have changing atmospheres, sounds, smells, levels of energy. Nocturne seeks to reflect this by transforming the way that a substantial piece of engineering is physically and imaginatively located in Newcastle and Gateshead. Like the slowly moving waters below the steelwork I wanted to create a light work that would constantly change so that at any given moment over the next 15 years it will appear to be in a different state."

The intensity of the white light modelling of the bridge structure, and the speed at which the colour message travels across the bridge, is determined by the rise and fall of the tide – the tidal algorithm. When the tide is out, and the water levels within the river are low, the luminosity of the white light is at its most intense. Similarly, the ebb and flow of the tide influences the speed at which the colour messages travel, as the tide rises the messages gradually move more slowly across the bridge and as it rises their speed gradually increases.

"The core of the idea is that light, colour and movement can play out over the decades and create an artwork that has different modes of behaviour and personality. It is not a simple visual idea, rather, Nocturne exploits circumstances to develop an identity."

Nocturne uses banks of LED (light emitting diode) lights set within the steelwork of the bridge. LEDs convert electricity directly into light and were first developed in the early 1960s. However it is only in recent years that more affordable and practical LEDs have become available and they are now very compact, extremely efficient in their use of energy and long lasting. The LEDs used to illuminate the QE II Bridge consume less energy in a year than is used by the average British household.

Nayan Kulkarni worked closely with lighting engineers to realise his vision for Nocturne as well as with Nexus’ own railway engineers to meet the challenge of realising such a large scale work within the operating environment of a railway.

"The special challenge was related to making sure that the artwork did not compromise the safe operation of the trains across the bridge whilst maintaining my vision for the way in which colour and light would change the structure. In my collaboration with Stephen Leary, who developed the computer control programmes for Nocturne, and Duncan Turner, from Lumivision who were responsible for the design and installation of the light fittings, we realised a light work that turned the initial vision into reality."

The closest analogy is that of a musical instrument which can change voice. Ours has to be able to change on the instruction of a train. In other words, as a train approaches the bridge it calms down the colour illumination by finding a pastel equivalent. When you consider that there could be up to 16.5 million colour variations on each of the 140 lights changing 10 time a second you can understand that it was not an inconsiderable technical task.’