TUNABLE WHITE LIGHTING FOR THE PORTA WESTFALICA BRIDGE IN DORTMUND-HÖRDE
The site of the former Phoenix blast furnace and steelworks in Dortmund-Hörde has been redeveloped to create the attractive “Hörder Dreiklang” quarter. In the east is Lake Phoenix with waterfront housing developments. Bordering it is the revitalised local centre of Hörde and the commercial estates in Phoenix-West – in a landscape connected by a network of numerous paths and bridges.
Built in 2012, in Hoetger Park, the pedestrian and cycle bridge, Porta Westfalica forms part of the network. Since last summer, it has been surprising passers-by with a dynamic light show realised with FLC200 projectors and Tunable White Technology from WE-EF.
With a length of 92 metres, Porta Westfalica is the longest of a total of seven steel bridges in Phoenix park. It completes the footpath and cycle path connection that goes all the way from Phoenix-West to Lake Phoenix and crosses the re-naturalised River Emscher. The material used is a reference to the area’s past as a centre of steel production, and its dynamic lighting concept is an example of how tunable white could be used to present outdoor installations in future.
“We deliberately decided not to use coloured light because colour would be too conspicuous and would make the Porta Westfalica too much of a focal point compared with other bridges and for local residents”, Uwe Knappschneider from licht | raum | stadt planung explained. “That’s why we played with warm white and cool white light, and showcased the bridge with tunable white.”
The variable colour temperature control, from 2700 K to 6000 K, opens up new possibilities for atmospheric lighting in outdoor areas. Warm and cool light colours can be used for nuanced highlighting of architectural details and to enhance the three-dimensionality.
“Tunable white is a great tool for presenting architectural features without being too showy, yet drawing attention to them in a very nuanced way”, according to Uwe Knappschneider. Project manager Helmut Wehrmeyer noted that “it’s the first time we’ve used tunable white in exterior planning and I’m surprised just how powerful the effect is.” Soft waves and smooth transitions
During the week and at the weekend two different subtle, dynamic light sequences of around 10 minutes are repeated in a loop. They sweep over the bridge in soft waves with smooth transitions from neutral white to warm white, and vice versa. Or they create a very slow rocking effect with monochrome cool white light and subtle increases and decreases in the light intensity alternating from the right to the left side of the bridge. There are small interruptions to the sequences. “The rhythm within the lighting scenario is increased for the blink of an eye as a small, short random interlude,” according to Managing Director of ledsdream, Thomas Waltenberger, who managed the project on site. He explained that people only become conscious of it after it has happened.
While the cool white lighting scenarios present the architecture of the bridge, the warm white scenarios create a pleasant atmospheric light that invites people to linger and sit on the benches in the green areas under and near the bridge. A special, very dynamic lighting scenario designed for events can be manually activated if required. Wide-beam and narrow-beam light in harmony
The bridge is showcased with 16 powerful DMX-controlled WE-EF FLC240-TW LED projectors with infinitely variable colour temperature control from a warm 2700 K to a cool 6000 K with constant luminous flux. Half of the projectors are fitted with symmetric wide-beam optics, while the others produce linear-shaped narrow-beam light distributions. Mounted on the arched lower tubular girders above the two central supports, they illuminate the opposite supporting structure in pairs with one wide-beam and one narrow-beam optic.
While the wide-beam optic illuminates the wide bridge soffit, the narrow-beam distribution brings out the contours and details of the tubular steel structure. Together, they produce nuanced illumination that is subtly yet effectively dynamised with the help of tunable white, giving the Porta Westfalica bridge a unique look and a distinctive identity.
Principal: NRW Urban, Dortmund
Architecture: Auer Weber, Stuttgart
Supporting structure: Mayr l Ludescher l Partner Consulting Engineers, Stuttgart
Lighting and electrical design: licht l raum l stadt planung gmbh, Wuppertal
Realisation: ledsdream gmbh, Düsseldorf
Photos: Frieder Blickle for WE-EF
Background:
For around 160 years, the steel industry shaped the Dortmund district of Hörde; Phoenix-West was known for its blast furnaces and Phoenix-Ost for its steelworks. Squeezed in between the two is Hörde town centre. The molten pig iron produced in Phoenix-West was transported by rail by the legendary “Fiery Elias” to the steelworks at Phoenix-East for further processing. In 2001 the “Hörde flare” was extinguished and the iron and steel industry in Hörde was consigned to the history books. Industrial sites with a total area of 214 hectares remained – and the huge challenge of developing this area following the end of steel production. The project “Phoenix – a new urban landscape in Dortmund was born – and on 27 September 2018 it was awarded the German urban development prize 2018.