Bilstein Cave Warstein - Modern LED technology instead of incandescent lamps

Position:                     51.428386, 8.321948

Length:                       400m

Show cave from:         1888                                                                         

Renovation:                September till November 2015                                    

380 lamps with 1500 watts of total power

Warstein - Modern LED technology instead of incandescent light.

Likely no one previously thought that the cave in Warsteiner Bilsteintal, which is partially filled with clay, would be overflowed with tourists. Of its total length of 1850 meters, 400 meters are opened for visitors. The show cave has been in operation ever since 1888. The lower part of the cave is closed for visitors, as it is often under water, due to the swelling of the underground stream. In 1937, drilling and blasting were used to create a 12 meter long tunnel connecting the cave entrance to the part of the cave that is decorated with stalactites.

While the town of Warstein is primarily known for the popular beer type, nowadays it is also worth taking a look at the Bilsteintal show cave (or Bilsteinhöhle, as it is known in Germany). Instead of the old unreliable diesel engine that was previously used, a battery has been installed as an emergency power supply, greatly increasing the safety. Also, the old Bilsteinhöhle lighting equipment, which had been in operation for more than four decades, was replaced in the autumn of 2015. The investment surpassed 165 000 euro, by witch the Bilsteintal Club, who owns the cave, managed to proverbially “kill two birds with one stone”: in addition to a much more effective lighting of the show cave, there would also be great energy savings, estimated at over 3000 euro per year (95% savings).

So the basic lighting of Bilsteinhöhle has therefore been renovated.

One important step was to implement the possibility to easily switch the lights on and off on different sectors of the 400 m long show cave, instead of the old system in which all the lights were kept on throughout the opening hours. So much light is very bad for any cave’s biology. Because of the naturally dark state of caves, any extra light leads to growths of lamp flora, comprised of several kinds of photosynthetic organisms, including mosses and ferns.

So with the current LED technology and new on-off switches that greatly reduce the amount of light in Bilsteinhöhle, the biological condition of the cave is also expected to significantly improve, and for this we have the example of other show cave projects that the Cavelighting Team implemented.

Two types of lighting have been installed and are currently in operation in Bilsteinhöhle, both systems depending on 24 V DC power supply: one system is used for highlighting the cave beauty creating effects and enhancing particular cave formations with focused spotlights, while the other, separate system, is used for antiglare pathway lighting.

Morning "on" and evening "off" is a thing of the past.

Modern equipment for cave lighting can be tailored to provide more than just two options: light and dark. Light can be dimmed or also color-controlled if desired. It no longer depends on one controller. The Cave Lighting team has supplied Bilsteinhöhle with its own tested technology system, by which lights can be switched on and off on different sectors with a push of the button by the cave guide as the group of visitors moves through the cave.

The cave operators have participated with ideas for the locations of lights and for the lighting effects. All these were installed by the Cave Lighting team in close cooperation with the operator.

We would like to thank the cave representatives, in particular Stefan Enste and Heinz Greifenstein, for their warm cooperation.

Oliver Heil


Further information could be obtained from:

Bilstein Cave Gallery

WDR report: Bilstein cave