Translations by: Dirk Steinforth
Ralf Keller
The development of Erdstall research in Central Europe. From the beginnings to 1975
The article traces the history of Erdstall research in Bavaria, Austria and the Czech Republic. Several events and periods can be observed that have linked knowledge and researchers and by that pushed research or slowed it down. For example, various articles in archaeological journals in the 1880s made the existence and spread of such structures in the three countries known to science. However, after the medieval dating of Erdstall souterrains had become established in the field by 1917, professional prehistorians in Germany and Austria hardly dealt with the Erdstall subject anymore. The research and documentation of structures was mostly carried out by laypeople and volunteers. This only slowly changed with the emergence of medieval archaeology since the 1960s. With the founding of a working group, Erdstall research received a new boost in 1973 (see Der ERDSTALL 48/49, 2023, p. 193–209).
(This abstract was translated by Ralf Keller.)
Hanna Schneck
Emil Wrbata – the first Erdstall photographer in Austria
As a qualified photographer of the Graphische Lehr- und Versuchsanstalt (‘Institution for Graphic Education and Research’) in Vienna, Emil Wrbata in 1896 was commissioned to accompany Father Lambert Karner on his excursions to numerous Erdställe in Austria. For Wrbata, who was only 20 years old at the time, photographing the narrow passages and chambers was a great challenge, as all photography had to be done using a flashlight that burned magnesium. In the poorly ventilated rooms its use was complicated and, due to the dense smoke it produced, dangerous. All the more remarkable is the quality that Wrbata’s pictures have to this day. They are regarded as the first Erdstall photographs, were presented in spectacular slide shows, and published in Karner’s renowned 1903 book “Künstliche Höhlen aus alter Zeit” (‘Artificial caves from ancient times’). It was not only in Erdstall research that Wrbata did pioneering work: his experience with difficult conditions for photography was of great value to the Vienna police department. After 1902, he was the director of the police photo studio and employed state-of-the-art technologies in the photographic documentation of crime scenes and investigations.
Martin Müller
State-of-the-art methods for the 3D surveying of Erdställe
For several years, various methods are available to determine the dimensions and designs of Erdställe precisely and in great detail, including photogrammetry, laser scanning, and LiDAR. This article outlines their individual characteristics, strengths, and weaknesses and presents a number of Erdstall surveys in which these techniques were employed.
Otto Cichocki, Bernhard Groiss, Mario Wallner, Michael Weissl
A less cost-intensive method for the high-quality 3D documentation of Erdställe
In the confined spaces of Erdställe, the installation of a scanner for the direct creation of a point cloud often is impossible. In recent years, however, an inexpensive way was developed out of photogrammetry/image-based modelling (structure from motion) technology to produce precise 3D visualisations of Erdställe by means of photography. The point cloud is generated out of a large number of overlapping photos and then coated with the photos’ colour values. This rendering can be carried out, for example, with Agisoft Metashape, AliceVision Meshroom, or other photogrammetry software. From the visualisation – which is rectified by calibrated reference points and from which therefore measurements can be taken – it is an easy matter to determine and display floor plan, vertical section, and passage sections at any desired position.
Kurt Niel, Raimund Edlinger
3D survey of the Erdstall Unterstetten/Tollet
A 3D survey of the Erdstall in Unterstetten in Upper Austria was conducted in November 2023, using a mobile scanner, which consisted of a tablet computer with a depth- and colour camera and a light mounted on the same handle. The measurements made it possible for various details of the Erdstall to be recognised and studied.
The Type-B Erdstall is about 800 years old and features a great number of characteristics that in this comprehensiveness are rarely found combined in one object: seven chambers, connected by a horizontal and five vertical slips; the chambers are arranged around a filled-in, elliptical construction shaft; lamp niches and benches are present as well as evidence of a defensive door with embrasure and closing stone; the overall length of the structure is 37 m, difference in level 6 m; one chamber has manually created furrows in its walls.
The Lenovo Phab2 Pro tablet combines colour camera, depth sensor, and gyroscope. Evaluation was based on Google’s Project Tango with RTAB (Real-Time Appearance-Based Mapping App) algorithm. Reference measurements with the 360° scanner Leica BLK360 were initiated. Insights from handling and reference contribute to the development of MOBES (‘mobile Erdstall scanner’).
The association “OÖ Erdstallzentrum Tollet Unterstetten” (‘Upper Austrian Erdstall centre Tollet Unterstetten’) aims to showcase the Unterstetten Erdstall and others to visitors without actually opening them to public access. An on-site multi-media presentation and virtual tours via the association’s website (https://OOE-Erdstallzentrum.at) are planned.
Hartwig Büttner
Early lighting technology in underground mining
Artificial light sources always have been indispensable and essential in the perennial night below ground. Only control of fire as a source of light and warmth and for the preparation of food and later the invention of techniques to produce fire made possible the exploitation of underground resources; and in the end, it contributed substantially to the development and geographical distribution of human cultures. Early forms of lighting included resin-impregnated wood shavings, simple closed or open lamps that burned – depending on availability – vegetal oils or the rendered visceral fat of ruminant animals (tallow) with wicks, and tallow candles. In mining, these primitive methods of lighting to some extent remained largely unchanged until the early twentieth century. It can be assumed that the contemporaneous means of lighting used by miners also were employed in similar underground structures, such as Erdställe, even though so far, there is no clear archaeological evidence for this.
Josef Weichenberger
The Erdstall at Reinolz 4, Dobersberg, Lower Austria
In February 2024, during renovation works on his farm at Reinolz 4, municipality Dobersberg (Lower Austria), a farmer discovered an Erdstall. The structure was flooded, however, and only after water had been pumped out for several hours, access became possible, using chest waders. It turned out that the Erdstall’s surviving length was 16 m. The surrounding ground is gneiss. Three passage extensions are no longer accessible.
With its narrow, winding passages, one slip, one crawl space, fifteen lamp niches, and one ventilation shaft, the structure features characteristic components of Erdställe.
It appears that after rainy days and during the snowmelt, ingress of water, flooding the Erdstall, creates a problem.
The owner aims at preserving the Erdstall.
Oliver Fries, Lisa-Maria Gerstenbauer, Alarich Langendorf, Andreas Steininger
New research on the Erdstall and the fortified church of Kleinzwettl (Lower Austria)
During the winter of 2022/23, within a project commissioned by the association “Zukunftsraum Thayaland” and supported by the EU, the authors prepared the concept for a showroom on the subject of Erdställe in the municipality of Thaya, which was to include five information panels and a walk-through, full-scale Erdstall model made by concrete printing, as well as five more information panels on the fortified church in Kleinzwettl (municipality Gastern) and the Erdstall beneath it. The insights gained during this process are the subject of this article.
The entry to the Erdstall in Kleinzwettl is located in the church’s choir. The Erdstall is 56 m long and terminates in a partly collapsed circular passage. After about 7 m, the winding corridor opens into a chamber that measures c. 4 x 1 m, is fully reveted, and features a barrel vault roof made of undressed stones.
Considered from a perspective of building history, it is particularly relevant to realise that during the late Gothic period, probably in the course of the construction of the current two-span vault of the nave in the 1460s, not only was the Erdstall treated with care, but even a certain amount of effort was made to keep it accessible.
Judging from the specific technique used in their masonry (so-called ‘Zwickelmauerwerk’), both the arched chamber beneath the nave’s northern aisle and the current entry to the Erdstall date from this period. Furthermore, a pillar of the nave’s vault, erected in the 1460s, is positioned partly on top of the Erdstall; and in order to avoid having to backfill and abandon it when the pillar’s foundations were laid, a stone slab was added as a lintel. The restoration works and conservation efforts mentioned above thus were carried out during a period when elsewhere, Erdställe had fallen out of use and some of them were backfilled.
Peter Wischenbarth
Erdställe and subterranean tunnels in and around the Landkreis Neu-Ulm (Bavaria)
Between the rivers of Iller and Günz in the Alpine foothills in south-west Bavaria ten Erdställe are known to date. Four of them had been found in or before the 19th century, six in the 20th or 21st centuries. One Erdstall very probably has a connection to a church, while four have entryways from cellars of residential buildings; five more Erdställe are located in open country. The study area’s geology uniformly features a yellow fine sand from the Miocene that was very well suited for the excavation of underground corridors. Archaeologically, the Erdställe are devoid of objects, with the exception of one tunnel in Deisenhausen. A ‘pot’ is said to have been found there, which is considered lost now, however. Particularly interesting is an Erdstall in the Archaeological Park Kellmünz with its late-Roman-Age fort; its system of corridors became apparent after a collapse of earth in 2013. The tunnels have a pointed ‘Gothic’ profile, and one room is accessible through a slip. This Erdstall is scheduled to be available for future research and therefore was fitted with a lockable entry. Apart from the Erdställe mentioned, there are in the study area numerous underground tunnels the walls of which have been faced with bricks or stone ashlars. Among other things, they probably were used for water drainage. The extent to which there also were genuine escape tunnels cannot be evaluated.
Martin Müller
An Erdstall in Thaya and its full-size model
An Erdstall in Thaya (Lower Austria) has been surveyed with both geodetical methods and a laser scanner. Using 3D concrete printing, a model on a 1:1 scale was created, which since 2003 is on display in the Erdstallzentrum Thaya (‘Erdstall centre Thaya’) and can be viewed and accessed there.
The innovative production method of this Erdstall model, which is the first of its kind, is presented, and it is hoped that this may inspire the fabrication of corresponding models of other Erdställe in the future. They allow visitors to gain information about the subject of Erdställe and to simulate personal inspections, while the risk of damage to the authentic Erdställe is reduced.
Franz Lindenmayr
The tunnels of Củ Chi in Vietnam
In the vicinity of Ho Chi Minh City in the south of Vietnam, between the Mekong river and the Cambodian border, a huge underground tunnel system of 300 km length has been built during the Anti-French Resistance War and particularly the so-called Vietnam War.
Today, it is a popular tourist destination that attracts many visitors.
As early as 1988, Karl Schwarzfischer pondered the question what Erdställe and the CủChi tunnels might have in common and what makes them different from each other. During a trip to Vietnam in 2022, I had the opportunity to inspect the tunnels personally and was very much impressed. They exclusively are structures designed for warfare that nobody wants to remain in for long voluntarily. If Erdställe ever served a ‘purpose’, it now for me is even more mysterious.
Otto Cichocki
Sir Karl Popper and the Erdställe
In a 1972 radio lecture entitled “Wissenschaftslehre in entwicklungstheoretischer und in logischer Sicht” (‘Epistemology in development-theoretical and logical perspective’), philosopher Karl Popper introduced the three-step formula of “1. problem – 2. attempt at a solution – 3. elimination” to the theory of science. Particularly the fact that in the third step, researchers are able to falsify and eliminate their own attempts at a solution, allows them to maintain their self-esteem and opened the way to the significant progress of modern science. This paper investigates the degree scientific Erdstall research follows Popper’s formula and its implications and in which aspects it can benefit from it.