The Dutch city of Emmen lies on the southern end of the Hondsrug, a 70 kilometer sand ridge crossing the province of Drenthe, to continue up to the city of Groningen. About 5500 years ago, the area was a major center of the Funnel Beaker Culture. The soil contains huge boulders, transported there from Southern Scandinavia by glaciers and used as building materials to make the mysterious dolmens (Hunebedden). Dolmen Light is based on these special boulders, 'The Gold of Drenthe', and located in a newly built tunnel. The tunnel walls represent the Hondsrug soil: dark boulders and organic spaces in-between. When looking in from outside a dolmen, you merely see black holes, but once you enter it, you are able to see the daylight vividly sparkling and twinkling between the boulders. The light installation reflects the past and connects it to the present with today’s latest techniques: a passage in time.
Northern Zoo
The light installation Dolmen Light in the Hondsrug Tunnel is one of the first projects within the overall development of city improvements in the center of Emmen. The construction of the tunnel is a direct result of the relocation of the Northern Zoo in Emmen, widely considered to be one of the finest zoos in Europe as well as an important part of the city’s identity. In order for visitors to walk freely to the entrance of the zoo from the completely redesigned center’s square, it was necessary to build a tunnel to hide the Hondsrugweg, a busy four-lane arterial road.
Tunnel
The concept of the tunnel is based on its location, the Hondsrugweg, where a passage through the sand ridge was dug out. To give users a sensation of driving in and out of the ground, the walls have been given a sandy color and a textured look to create a ‘soft’ ambiance. A hard, industrial look was chosen for the overall appearance of the tunnel as this high-grade technological structure was constructed in the sand ridge, adding a new, underground building to the city. The start of the light segments is visible to non-users of the traffic tunnel, such as pedestrians and cyclists, at the entrances of each tunnel tube, making a connection between above and below. Instead of a necessary evil, i.e. a situation in which slow and fast road users clash, an attractive ambiance has now been created for both parties. Because of their visibility from the outside, the same light program will never run simultaneously in both tunnels because they are controlled individually.
Experience
The initial challenge was to discover whether dynamic light could be applied to a tunnel that is used by motorized traffic. Some drivers feel insecure when driving into a tunnel and this is exactly why the most serious accidents occur there. Usually this means that during the construction of a tunnel the main focus lies on safety, and a grey color scheme and purely functional lighting is opted for. This kind of concept is based on fear and barely takes positive human irrational behavior into account. To counter this narrow outlook, the drawings have been tested in a driving simulator at Delft University of Technology. These tests proved the opposite. Entering a tunnel normally takes drivers from a dynamic environment into a static one, while the light art actually renews and complements the organic contact between the road user and the space. Drivers feel welcome instead of locked up. It turns out to be an impressive and most pleasant experience to drive through this tunnel. The lighting effects move with the vehicles as they make their journey through the tunnel. The lighting transports travelers back to the era of the dolmens, with organic shapes, and guides visitors into the future of urban light design with changing colors as cars drive through.
Light program
A pre-programmed palette of colors gradually turns into a different palette as you drive through. The light program in the tunnel adapts to the traffic’s speed, usually about 50 kilometers per hour. The basic program’s lapse of light and shade is, both horizontally as well as vertically, flowing and gradual. The tunnel was opened recently, on December 19th 2014, and slowly but surely more content will be added, for instance a link between the programming of the lighting and video footage of animals in the zoo to create slow-moving patterns within the lighting. Moreover, other specials will be added to the program, such as one for Butterfly Day, a special event in the city of Emmen, or a special program during the Emmen Marathon, which will give athletes and pedestrians access to the tunnels. Recently a King’s Day special was added to the content during one day when the Dutch King and Queen visited on February 19th last, two months after the opening. Instead of a gradual and flowing pattern, road users were able to experience a completely different light pattern. Consisting of the colors red, white and blue (the Dutch flag), orange (House of Orange) and the colors that are created when these colors are mixed, such as pink and purple, the color patterns waved in long strips through the tunnel, much like a flag waving in the wind. In this case, instead of a gradual play of light, sharp rays of light took over the tunnel. This special came as a surprise to road users; they were given a complete, highly dynamic experience for a single day.
Technical description
The light installation consists of twelve modular elements which can be replaced. With these twelve modular elements, two different segments were built; the segments were copied 40 times, some rotated, and installed in the two tunnels.
The 700 closed IP 67 elements are addressable and individually controllable. The RGB LED, over 3,962 m. (13,123ft) in the elements is equipped with 1Color Flex MX fixtures and powered by a LPC20 rack mounted controller. The combination of two optics, the LED cell and the light cover over the LED, results in a smooth light emission.
To make sure that the tunnel is lit sufficiently in the event of a malfunction of the wall lighting, the norms as stated in the Dutch tunnel guidelines have been adhered to for the functional tunnel lighting. In the future the communication between both installations will be adjusted on the basis of experience. Emergency lighting that will switch on in case of a calamity has also been fitted in the tunnel barriers.