Made by Cave Lighting: Schillat Cave, Lower Saxony, Germany, February 2013. Feedback, November 2013

Schillat Cave is known to be Germany’s northernmost limestone cave. It is situated on the north side of the Süntel near Langenfeld, Hessisch-Oldendorf.

Schillat Cave was discovered in 1992 by Hartmut Brepohl when he opened a cavity whilst blasting in the nearby quarry. The show cave was opened to the public in 2004.
The cave, situated in one of the quarry walls, was made accessible by erecting a modern visitor’s centre on the edga of the cliff from which an elevator descends 45 metres to the entrance. The cave is open all year round. In summer 3 – 4 guided tours are conducted simultaneously.

Schillat Cave is known throughout Germany because of Bodo Schillat’s archive of calcareous sinter exhibits. Several hundred different calcite formations collected by Benno Wolf Prize awardee Bodo Schillat are displayed within the cave. Showcases of plexiglass were installed beyond the tourist path to protect the exhibits from unruly visitors. In time however, these constructions proved to be unsatisfactory because they became fogged by condensation, thus blocking the view. In an effort to overcome this problem, the management decided to install fan heaters. For years thousands of kilowatts of electricity were blasted through the cave in the form of hot air, causing the temperature to rise to up to 14° C. and resulting in excessive growth of diverse flora with great detrimental effect on the exhibits and on the cave itself.
The show cave could no longer be presented in such a sorry state, so, in 2012, the council of Hessisch-Oldendorf chose to invest in the instalment of modern and environmentally friendly LED lighting.

After clarification of the financing via the LEADER-Programme and installation planning by the planning office Fohlert, the specialists from the Cave Lighting Project went into action.

Following the dismantling of the old, overly dimensioned halogen illumination system, installation of the new lighting was carried out. Accent lighting was added to the subtle illumination of the paths as a further enhancement. Although the very narrow passages made the installation of the cables for these forms of lighting difficult, the Cave Lighting specialists could rely on their skill to overcome this problem. The result of the introduction of the new lighting is convincing to both the exacting visitor and local speleologists alike. Schillat Cave was once notorious for being Germany’s worst illuminated show cave. Now this reputation is a thing of the past. The switch to LED lighting was the only correct decision to be made in order to conserve the cave and its sinter exhibits for time to come.

Schillat Cave has now been open to the public in its new look since March and many thousands of enthusiastic visitors have already taken the opportunity to admire the "new" show cave.

Thanks to the well-conceived installation and the intelligent electronic switching for separate zones within the cave, a significant reduction in the detrimental lamp flora was noted after only three months. The plants lose their chlorophyll, become transparent and slowly die off. This development bolsters the philosophy of the Cave Lighting teams and proves once again that our efforts are not only based on the economical and aesthetic aims of our customers, but also and most importantly on the conservation of our caves.

Schillat Cave

Location: Langenfeld, Lower Saxony, Germany
Position: 52° 12′ 17″ N, 9° 17′ 17″ E
Show cave area: 180 m
Show cave since: 2004
Number of visitors: ~ 25.000 per year
LED installation: February 2013
LED equiment: 135 Lamps with approx. 500 watts total
Old lighting: about 12.000 watts

Update 2013 - 12 - 20. Feedback.

From: Dewezet Hamlin
Wednesday, 27th November 2013
Page 24

“Chemicals are out of the question“

Mosses and ferns grew rampant in Schillat Cave / New lamps should help – a success?

By Annette Hensel

Langenfeld. “The struggle against mosses and ferns” – that was the headline in the Dewezet last February. In future, a new lighting concept should stop the growth of mosses, fungi, lichens, algae and ferns in Schillat Cave.

The problem at the time: the lamps illuminating Schillat Cave since 2004 had a negative side effect. They allowed mosses, algae, lichens, fungi and ferns to grow, even on the formations 40 m below the surface (we reported on this). The warmth emitted by lamps altered the climate below ground. Floodlights and neon lamps illuminated the cave until now. There should be a constant temperature of eight degrees but nine or ten degrees could be observed in areas surrounding the floodlights.

Positive experience with LED technology in other show caves in which the climate has remained constant and where mosses and algae degenerate of their own accord led to its installation in Langenfeld.

Following the dismantling of the old lamps, whose maintenance was expensive due to several technical faults, modern, energy-saving LED lighting was installed in February. The cost: 40,000 Euros of which around 28,000 had to be contributed by the town of Hessisch Oldendorf. The remaining sum was granted by the European Union’s Leader Programme.

The lighting system in the show cave area was completely renewed because the lamps that were installed nine years ago no longer meet current technical standards. The new lamps are less prone to failure and use 90 per cent less energy.

Nine months have since passed. Has the new lighting technology passed the test?

Speleologist Hartmut Brepohl, who discovered Schillat Cave in 1992, states: “Since spring, geologist Dr. Uwe Peters and his students have taken samples on three occasions in order to determine whether the cold light reduces the growth of mosses. We speleologists have already been long convinced that the growth is diminished. I always point this out to the visitors when conducting a tour.”
Instead of illuminating the whole area, exhibits and specific parts of the cave are spotlighted to achieve a better effect.

“Of course, we hope the unwanted vegetation will disappear completely and shall observe the development in the coming year” expressed Brepohl.
“If necessary we shall have to remove by hand the large ferns that have not yet diminished. I shall not allow any chemicals in the cave”.
“I personally am more than satisfied with the new technology, for the LED lamps add optical enhancement to the cave by spotlighting attractive features.”

The lamps have also made an economical impact due to the enormous reduction in power demand.
“With the floodlights and neon lighting 15,000 watts where necessary to illuminate the whole cave, now we only need 300 watts. This has led to a noticeable decrease in the temperatures that support the growth of mosses, algae, fungi or ferns.“