Gymnicher Mühle, Erftstadt

A strong river theme, explored from different angles, runs through a historic watermill that is home to the KM 51 – Erftmuseum. Light serves as a didactic element in the exhibition, guiding the visitor through its interactive installations.

What might it be like to follow the footsteps of Moses passing through the waters on dry ground? What would be the impression of flora and fauna along the way? How does the color of water change with its depth? What do reeds look like over its full length? And how does a beaver catch fish? These and many other questions are answered in the “Flusskörper” at the KM 51 – Erftmuseum. Simulating a watery river run, the installation is designed as an oblong walk-in room with graphics and exhibits presenting cross sections of a river with its abundance of animal and plant life. The room gives perspectives to visitors that are otherwise reserved only for divers.

Nature reserve center with watermill in the recreational area of Cologne
The Gymnicher Mühle is an ancient watermill located at river kilometer 51 on the Kleine Erft, a tributary of the Rhine near Cologne. Once used to grind grain and press oil, archaeological excavations suggest that the watermill existed as far back as the 9th century. Owned by Siegburg Abbey, the mill was operated by the aristocracy of Gymnich, who, over the centuries, moved its site by a few kilometers, remodelled the mill and homestead, and controlled the flow of the river. The Gymnicher Mühle was eventually closed down in 1948 and all technical equipment removed with the exception of the mill wheel and its hydraulic system. In 1984 the three-winged structure was given landmark status. In 2005 German milling association Mühlenverband Rhein-Erft-Ruhr acquired the entire property and converted it into a nature reserve center, which now includes the KM 51 – Erftmuseum. Extending over more than 450sqm, its exhibition models the 103km stretch of the Erft from the source to the estuary. Twelve interactive stations convey special regional features with references to global river and water topics.

Historic half-timbered structure fitted expertly with track system
The project’s exhibition designers, mgp ErlebnisRaumDesign, engaged lighting design office Inlux to develop a scenographic lighting concept tailored to set the right ambience for the experience. An ERCO track system was installed in the listed half-timbered structure and fitted with Pollux and Optec spotlights with a DALI control system. Staged with dramatic effects of light and dark contrasts, the visitor’s attention is guided from one exhibit to the next, whilst the specially developed ERCO LED photometric solutions create an interplay of light and shadow designed to emphasize specific structural features of the historic building, such as the illuminated roof structure with its resident imp. “By giving detailed and careful thought to the track system and its position in the old section of the Gymnicher Mühle we have created an infrastructure that allows the illumination to change with any rearrangement of exhibits,” concludes Florian Reißmann of Inlux. As an eye-catching feature, the magic shine of a light wave, made of wires that appear to be self-illuminating, runs through several rooms like a rivulet, and is channelled to cascade down the exhibited mill wheel and along the river water body, before it weaves through the building’s timber frame.

Subtle and flexible museum lighting for dynamic light scenes
The foyer offers a dynamic lighting scenario using an audio file to emphasize the exhibits. The challenge here lay in programming the interface between media control system and DALI. “The media control system originates from the theater and uses its own protocol,” explains Florian Reißmann. “Spotlights used in a theater setting are not equipped to implement subtle and flexible museum lighting.” The backdrop, for example, includes a bell that at first glance appears to swing back and forth. Closer examination, however, reveals that the two spotlights illuminating the bell operate in time with each chime to cast a shadow that moves from side to side.

A spot on the wall for good luck
One special item in the mill points unmistakably to an exhibition organized by experts with a love of nature. Whilst the mill lay idle, it gave home to nesting swallows that continued to fly through the open windows as renovations advanced. The interior had just been given a fresh coat of paint when one of the swallows proceeded to drop a special gift. “As it flew past the wall, it deposited its ‘good luck message’ right there, on the fresh blue paint,” remembers Florian Reißmann. The designers decided to weave this story into the exhibition, accentuated by a spotlight that had not originally been part of the concept.