1. Show cave on the High Tatra.
The mystery of caves and the unknown world lying beyond the last rays of daylight at every entrance has seduced people for ages. Exploring the underground world has been a human need from prehistoric times and it is somehow encrypted in modern man, most visible in cavers. From the ancient torch to the high-tech LED, we have always found a way to bring light into the cave’s darkness to reveal their treasures.
The spectacular landscapes of the High Tatra Mountains are world famous, but their underground is less known. Among all High Tatra caves, only one has been equipped as a show cave. Belianska is the cave where all the requirements for a visit to the underground world of these mountains are focused.
Belianska cave is located within the Tatra National Park, in the eastern part of the Belianske Tatra Mountains and was first opened for visitors in 1882. The first electric lighting was installed in 1896 with major changes carried out in 1950 and 1980. With a 1370 m long visitor’s path and an elevation range of 125 m, Belianska presents quite a challenge for any construction team willing to improve or change the infrastructure.
2. Why LED lighting system?
As LED lighting becomes more and more available, show cave managers around the world have started to implement it, abolishing older systems with incandescent light. With several show caves in the vicinity, the Slovak Caves Administration (SSJ) was at first skeptical regarding the new LED-based lighting techniques. But anyway, in 2012, after some good international reports, SSJ decided to test the LED lighting fixtures of Cave LightingTM in Belianska Cave. It was a long and difficult journey from the idea of lighting all of Belianska Cave with LEDs to the beginning of installation of these fixtures. A lot of planning work had to be done to improve the cave’s visiting facilities, and sheet by sheet, papers gathered in folders transforming ideas into objectives, giving birth to a project which will eventually radically change the outlook of Belianska as a show cave.
The effective work was first scheduled to begin in January 2015 with a four month deadline, during which several teams from different companies had to cooperate and synchronize work in order to successfully finish the project. The tasks? First all the old installations from the cave had to be taken out removed (handrails, power cabinets, power cables, lamps, communication devices), and then all the new equipment had to be installed.
3. Snowy start of construction .
The Cave LightingTM team arrived at Belianska show cave in February 2015 and was positively impressed by the work that was going on. The path with a length of 1 km and a height difference of 120 m that leads from the car park to the cave was covered by snow and only accessible
by on foot. Inside the cave the view was totally different from the previously silent halls with dripping water. People were working in teams, like ants - cutting, welding, digging… an endless construction site. Some new handrails had already been installed, main cable ways opened, cable rolls and boxes containing new equipment stored in several places.
Two main contractors were involved on the site: one to carry out the construction of the stainless steel handrails and another for the electrical work (BBF-Elektro). BBF is a Slovak company responsible for all electrical work needed for the renewal of Belianska Cave lighting and in-cave communication. The light design had been completed in the planning stage by SSJ together with the local cave management. It included a very useful list of lamps with a nice combination of white nuances. This was also required to enhance the geological complexity of the cave.
Before getting to work, several teams were put together in accordance with the tasks. It was important to establish a common means of communication between the people of different nationalities involved in the project. One common language turned out to be not enough, and communication had to be carried out in Slovak, English, Russian and German. At first, this felt like an inconvenience, but it turned out that professionalism does not depend on language.
4. Cave Lighting™ lighting system in Belianska cave.
The first lighting fixtures were installed between the areas known as the High Dome and the Palm Hall. As the LED lamps replaced the older lighting in this part of the cave, different views started to emerge. Different people, different opinions, but often the most relevant ones were those of the guides who operate in the cave. Trying to change something that was embedded with the cave for years is not easy, so, as it happens many times with lighting renewal for a show cave, the guide’s first impression was not very positive. Words like “It is not like before”, “It is too different from…”, “Looks good, but…” were used. An important role in the placing of lighting fixtures was then taken by the guides who pointed out the key dripstones, draperies and legendary places of the cave.
Belianska Cave is currently logically divided into eight lighting zones which can be switched on/off individually, two light-show zones each with different light scenes and one music-light zone, called the Music Hall. In the Music Hall three music-light shows were implemented, where sound is gently synchronized with lights. Also, one of the songs was composed in the cave and with 6 audio channel outputs it creates the feeling of a “living cave” with moving walls and flowing water. In the show parts of the cave all the lighting fixtures are individually programmable, so that with
a proper programming they offer the best views for visitors who are not at the first trip. All these zones are designed to be operated by the guides with an eight-button remote control. By comparison with the first weeks of installation work when the guides were skeptical about the new lighting, afterwards they gladly discovered the amount of possibilities available at both switching and light scenes. Over 700 LED lighting fixtures were installed in Belianska Cave to provide visitors an unforgettable underground experience. With an installed power not exceeding 5 KW, Belianska Cave, with its great halls, enters the list of low power consumption caves.
This was about the visible aspects of the cave’s lighting infrastructure. What is hidden from the visitor eyes is the technology behind all these, the hard work done by the people while installing cables, power cabinets, lamps in difficult places, handrails over chasms. There are also two networks present in the cave, one Cave LightingTM network which interconnects radio receivers, lamp controller units and power cabinets, and one ring fibre optic network between power cabinets and one central control outside
of the cave. Through the Cave LightingTM network the guides are able to remotely turn on/off current lighting zones and switch between light scenes. Also button controllers are connected to this network in the switching points to back up the remote control in case it gets damaged or lost. The backlight of these buttons was turned off and they installed facing away from the visitor path to avoid accidental pressing.
5. Visitors safety.
For visitor safety, all path-lighting fixtures are connected to UPSs inside power cabinets, so in case of power failure there won’t be total darkness inside the cave for 30 seconds, the time needed for the automatic diesel power generator to start up and reestablish normal functionality. The automatic diesel power generator has 8 hours autonomy, so in case of a longer power failure, guided tours will not be affected. More than five visitor groups can pass through the cave simultaneously without affecting the quality of the guided tour.
Through the fiber optic network, central control receives status messages from each power cabinet and can send back commands. Messages such as warnings and/or alarms regarding fuses, UPS status, battery status, network connection are displayed at central control on a web panel so that people in charge can take immediate action if needed. Also, from central control, lights in the cave can be switched on/off for the entire cave or by zones, if needed. Network control and power cabinet automation was implemented with Phoenix Contact equipment.
After finishing all construction work inside the cave, testing the functionality of the lighting system in all possible cases was one of the last tasks of the teams involved. Belianska Cave is now ready to receive visitors, with a new outlook to reveal its underground wonders.
Cave LightingTM team wishes to thank everybody involved in the Belianska project for the professional work and the good results achieved.
Gallery Belianska cave ©. Pictures by Szymon Kostka and Adrian Kondacs.
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