Drawbar
A Deichel , Teuchel , Deuchel , - in Switzerland - Tüchel , Dünkel or Pipe ( vlat: pipa, tube ), is a wooden tube made by central drilling through a tree trunk, which in pre-industrial times was widely used as a water pipe, especially in areas of Central Europe rich in forests and water was relocated. These were referred to as Röhrwasser , in Saxony also as Röhrfahrt , in Franconia partly as Rohrfahrt and in Harz as a water journey . Ernst Ochs , editor of the Baden dictionary , traces the term Deichel back to the Latin word ductile .
Manufacturing
The manufacture of a dike required great skill from the craftsmen, which is why dike drill or pipe master was a respected profession that was practiced in the vicinity of large forest areas because of the need for wood. According to him z. B. the "Bohrertal" and the "Bohrerbach" on the Schauinsland in Horben near Freiburg im Breisgau .
The drill was guided exactly horizontally and the tree trunk was moved over wooden rails on a wooden cart. In modern drilling machines, the continuous thread and the speed of rotation ensure that the chips are transported out of the hole when drilling. In pre-industrial times, however, it was not yet possible to manufacture two meter long iron bars with a continuous drill thread. Since you therefore had to drill deeper than the thread was long, the drilling had to be interrupted after a few turns in order to first pull out the drill with the chips jammed behind it and then start again.
Before drilling, the logs cut in the sap, preferably from resin-rich pines or firs , but also oaks , depending on availability, were stored with their straight shafts in ponds and ponds (dyke ponds). Many names of smaller bodies of water testify to this, such as the Teuchelweiher in Winterthur , the Deicheleweiher in Freiburg im Breisgau or the Röhrensee in Bayreuth. Here fresh logs could be kept airtight and safe from fluctuations in humidity - so that no dry cracks developed during storage - "in stock" until needed.
In order to produce a wooden tube from three to four meters in length, the log had to be drilled open from both sides, which required precise guidance. Nevertheless, it happened again and again that, for example due to adhesions, the holes from both sides did not meet each other exactly, but more or less offset. A so-called dike mouse was used to check whether there was sufficient patency . It was probably a device with a mouse-like headboard and a thin handle that was longer than the drill used. The aim was a clear width of 5 to 6 centimeters, which could also reach up to 10 centimeters.
The hollow tree trunks were then connected with metal rings hammered into the front wood on both sides , the so-called drawbar rings, and if there was a leak, they were subsequently sealed with pitch or the like. If necessary, pipes or pipe connections were additionally sealed with surrounding metal rings made of iron, copper or tin. Ready-made replacement parts for pipe replacement were also kept under water in the dyke ponds so that no dry cracks developed during storage.
As an alternative to the continuous drilling, the trunks could also be split, hollowed out one half after the other and then put back together again. The joints were sealed with tow , pitch or on the end faces with cylindrical iron rings (buses).
Saltworks pipes
Dykes were not only used for drinking water pipes , but also for brine pipes, for example for the Bad Reichenhaller Saline.
In the course of the brine pipeline west along the Hallstätter See, the valley of the flowing Gosaubach was crossed as a three-strand pressure pipeline at a depth of up to 23 m, i.e. with about 3 bar overpressure, before a high bridge was built (1758). In this high-pressure section (estimated at 3 bar), which is known as Gosauzwang , the line was therefore divided into 3 smaller-diameter strands and the shafts were reinforced with wrought-iron rings.
lifespan
Dyke lines could have a lifespan of ten to 100 years, whereby the nature of the surrounding soil mattered, which had to be as consistently moist as possible, which is why the lines were often sheathed with clay. It was also important to prevent air from entering the pipe. In the case of drinking water from dyke lines, an unpleasant taste was often noticeable, with older lines the quality of the water was often questionable.
In some remote forest areas in Germany, dike lines were operated until the end of the 20th century. Even in cities, after the Second World War, such wooden pipes were still occasionally in use. In the city of Salzburg, for example, water flowed through the city's last wooden dyke line, the historic Sternweiherbrunnenleitung, until 1976. The aqueduct that gave the Freudenstadt Teuchelwald its name and was in operation until 1952 existed for a similar period of time .
A line made of several meters long (outer diameter no more than 8 cm), axially drilled out wooden poles, which supplied the hut at Grünen See , Styria, was only replaced by a plastic line around 1990. A tiller was still in good condition at the bottom of the lake around 2000.
gallery
Hand drill for making wooden tubes
Sighting with the help of a cord and setting the drilling direction using a height-adjustable bracket
Start of drilling
Removal of the swarf drilled out after a few turns
Tip of the drill with tube
Boring a Teuchel
Drawbar ring made of metal and drill point
Individual evidence
- ↑ Christian Friedrich Schröder : First continuation of my treatise on the Brocken Mountains, or letters to the lieutenant engineer Lasius, about various height measurements, two large magnetic rocks discovered, and other strange objects from the Brocken Mountains . Tuchtfeld, Hildesheim 1790, p. 11 ( digitized version ).
- ↑ a b Gerhard Endriss: The artificial irrigation of the Black Forest and the adjacent areas. In: Reports of the Natural Research Society in Freiburg im Breisgau. Vol. 42, No. 1, 1952, pp. 77–113, here p. 103, ( digital version (PDF; 4.16 MB) ).
- ↑ a b c House for historical handicraft / Allgäuer Burgenverein eV (ed.): The Deichelbohrer. 2012.
- ^ Mathias Döring: Weilburg and its water. The water supply of the baroque residence in the 18th and 19th centuries (= writings of the German Water History Society (DWhG) eV special volume. 1, ZDB -ID 2299939-5 ). German Water History Society (DWhG), Siegburg et al. 2005, pp. 19–20.
literature
- Harald Roscher: Thuringia's water supply from the Middle Ages to the present. 130 years of uniform water supply in Thuringia. A contribution to the history of technology. Universitätsverlag Bauhaus University, Weimar 1999, ISBN 3-86068-105-2 .
- Gerhard M. Veh, Hans-Jürgen Rapsch (ed.): From wells and twitching, piping and water arts. The development of the water supply in Lower Saxony. Wachholtz, Neumünster 1998, ISBN 3-529-05115-2 .
