• Saturday , 23 October 2021

AV Project of the Year (Education) 2021

Modernization and expansion of the exhibition of the Underground City “Osówka” 

Gloomy, cold, empty hallways got filled with multimedia stations that, like a time machine, take the visitors back to the days of World War II.

Old information boards, which at this point had their ink long melted, were replaced with stylish light boxes, a scale model with 3D mapping and beautifully illuminated display cabinets. The haphazardly piled artifacts were exhibited on modular podiums illuminated with spotlights. Instead of grotesque mannequins, the tourists visiting the tunnels of Osówka meet holograms of concentration camp inmates, forced laborers and German soldiers. That way they learn the struggle of hard, slave labor of building Hitler’s quarters, while also exploring the mysteries of the facility’s unclear purpose, which still hides a lot of secrets. All of that turns visiting the facility into a fascinating, reflection-provoking tale of the difficult topic of war and holocaust.


The investor demanded a 7-year warranty for the entire exhibition from the contractor. It was quite a challenge because the conditions in the facility aren’t conducive to electronics: high humidity constant at the level of 90% and a low temperature of approximately 8 degrees Celsius. The underground climate makes it necessary to protect each device against moisture. The brand that offered IP5X tightness, a 7-year warranty, and displaying of an amazing quality images with laser projectors in a humid and cold environment was Optoma. Two projector models were chosen during the implementation of this investment: Optoma ZU510Te and Optoma ZU500TST.  In total, 8 devices of this brand were used in the entire facility.


Holographic figures are the guides through the history of the creation of the Riese. We have created three such quarters in the Underground City “Osówka”. In the first one, visitors are greeted by a hologram of the famous Polish actor- Adam Ferency. The virtual figure of an actual size is displayed on a holographic fabric that is stretched over a 300 cm x 188 cm hand-made frame using the short focus Optoma ZU500TST projector with WUXGA resolution. Additionally, while the virtual figure of the actor tells tourists about the history, archival videos from World Wat II are being displayed on the 65’’ Iiyama LE6540 UHS monitor, with subtitles in two language versions.

The backlight connected to the control system is responsible for eliminating the effect of double image reflection. The light turns on in the moment when projection starts and turns off after it ends.

In the second quarter, the holograms of prisoners dressed in the striped uniforms present the tragic story of the concentration camp prisoners building the Riese complex. There is also a movie about the martyrdom of prisoners displayed on the holographic fabric. The scenography is complemented by a replica of the rock shelter- a metal trolley running on the rails used at the Riese complex. The backlight of the rock shelter turns on automatically when the hologram is being displayed and turns off automatically when the movie starts playing. The projection is displayed with a short focal Optoma ZU500TST projector with a WUXGA resolution on a holographic fabric that is stretched over a 300 cm x 188 cm frame of own production.

The third quarter imitates realistic workers working on a stage design scaffolding, which faithfully reproduces the original scaffolding from the period of World War II. An Optoma ZU500TST with a WUXGA resolution was used to display the image. The projection area of 300 cm x 188 cm without the fabric was projected directly on the rocks by means of mapping.

Each of the holographic positions is managed by an IntelNuc i5 computer with an original control system. A set of Work Pro Neo 5IP waterproof speakers and the SoundTube SA202 amplifier are responsible for the sound. All devices are in covers.


To show the scale of the Nazi’s venture, a model of the topography of the area was made, with additional space for displaying translations into foreign languages, on which historical maps are displayed by using mapping, including the locations of the particular objects and plans of underground corridors. It was projected by the Optoma ZU500TST show throw projector with WUXGA resolution. It is entirely managed by the IntelNuc i5 computer with an original control system. A set of the Work Pro Neo 5IP waterproof speakers and the SoundTube SA202 amplifier are responsible for the sound.


Three display cases finished with weathering steel (corten steel) panels were placed on the tour route. The air dehumidifier system is responsible for the right conditions for the exhibits. Cabinet humidity switch HYW 090 measures the air humidity inside the showcase. If the humidity exceeds the set value, the Dehumidifer for Enclosures PSE 30 L activates, draining the moisture outside of the showcase, leaving an inside atmosphere friendly for the exhibits. This system also eliminates the problem of evaporation inside the showcases.


Tourists can choose from several sightseeing routes. One of them is the water crossing. Visitors overcome this route on an old tin boat and sail on it into the ‘dry’ part of the corridors. On this route, we installed the PXM company’s underwater lightning based on a DMX controller which allows to turn on 7 different effects. Specially prepared, illuminated graphics with an imitation of a sunken truck and a sunken ship with boxes full of gold are additional attractions.

Testimonials and references

Agnieszka Dobkiewicz, a journalist at Gazeta Wyborcza, one of the leading daily papers in Poland, says in an article on the new route in the Underground Town of Osówka: “When you’re in a WW2-era underground location that was dug by concentration camp inmates, and there’s suddenly a hologram of a person emerging from darkness in front of you, it gives you goosebumps”. That’s the exact type of effect we aimed at when creating the exhibition.

The AV Integracje magazine, renowned in the A&V industry, has made our project their cover story. The exhibition at the Underground Town of “Osówka” was described in detail on nine pages of the magazine, presenting our installation as an example of proven solutions in extreme conditions.