An Erdstall – What is that?

An Erdstall is a man-made underground tunnel system. It always has only one entrance, and thus never forms a connection between two places.

Passages

A characteristic of the Erdställe are its narrow and low passages, which can only be passed through in a stooped posture or even by crawling on all fours. Depending on the ambient rock, the corridors’ ceilings have a round or a pointed arch. Longer sections do not run in a straight line, but always are designed with curves or bends. The separate passages never run in the same direction or even on the same level, but intersect, have steps, or form circles, thus creating the impression of a maze.

Chambers

The passages frequently widen out into cave-like chambers with slightly more headroom. Occasionally, there are ledges in the ground that are reminiscent of benches.

Slip holes

Mysterious, but characteristic for the Erdställe are the so-called ‘Schlupfe’ (‘slips’). Certain sections of passages and chambers often are connected by narrow slip holes or slip tubes with a diameter of less than 50 cm. They may be horizontal or vertical, and even for lean persons getting through sometimes is very cumbersome.

Step and slip hole in the Erdstall of Wösner, Austria. (Photo: Peter Forster)

Passage and horizontal slip hole in the Erdstall of Oberviechtach, Lkr. Schwandorf, Germany. (Photo: Peter Forster)

The vertical slip hole in the Erdstall of Trebersdorf, Lkr. Cham, Germany. (Photo: Peter Forster)

Niches

In the walls of many Erdställe, there are recesses of different sizes: Those among them that theoretically can accommodate a person traditionally are called ‘sitting niches’. Smaller recesses in the walls, on the other hand, are interpreted as light niches or as having been used for feeling one’s way in the dark tunnels (‘Tastnischen’).

Those Erdställe that researchers have been able to explore thoroughly, are very different from each other in size and form. Many are only incompletely preserved or partly backfilled, thus rendering full documentation impossible.

Great niche in the Erdstall of Mitterschneidhart, Lkr. Kelheim, Germany. (Photo: Birgit Symader)

Niche with soot marks in the Erdstall Obergrund, Lkr. Altötting, Germany. (Photo: Peter Forster)

Steps in the Erdstall of Grasfilzing, Arnschwang parish, Lkr. Cham, Germany. (Photo: Birgit Symader)

Access

Walled-up construction shaft in Grasfilzing, Arnschwang parish, Lkr. Cham, Germany. (Photo: Peter Forster)

Nowadays, access to an Erdstall usually is via either a sloping slip passage or a vertical shaft. Very little is known about the original entrances.

Ancillary construction shafts

During work on several of the tunnel systems, an ancillary construction shaft was sunk into the ground, which was then used to remove the loose material of rock and earth from the newly dug passages. Afterwards, many of these shafts were closed off with dry masonry and then backfilled.

A typical Erdstall

Passages, chambers, slips, niches, and an ancillary construction shaft – the Erdstall of Schnepfenbühl (Windischeschenbach, Lkr. Neustadt an der Waldnaab) combined all characteristic features. It was destroyed during construction of a motorway in 1977.

Visualisation of the Erdstall Schnepfenbühl. (Manntau, based in a graphic by Harald Fähnrich)