Dara dam

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Dara dam
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Location: Dara ( Turkey )
Tributaries: Cord
Dara Dam (Turkey)
Dara dam
Coordinates 37 ° 10 '59 "  N , 40 ° 57' 4"  E Coordinates: 37 ° 10 '59 "  N , 40 ° 57' 4"  E
Data on the structure
Lock type: Arch dam
Construction time: Approx. 560 AD

The Dara Dam was a Roman arch dam in Dara in Mesopotamia (today's southeastern Turkey ) and one of the few examples of this type of dam in the pre-modern era. The current location of the dam is uncertain, but could rather indicate the common type of gravity dam .

Ancient lore

The construction of the dam was handed down by the Eastern Roman historian Prokop in his treatise on the architectural achievements of the Justinian I era ( De Aedificiis 2.3.). His report is of particular interest from a technical-historical perspective: for the first time, a clear understanding of the functional principle of an arch dam can be seen, which differs greatly from the gravity dam that was common in antiquity and beyond .

Prokop emphasizes two essential functional principles: on the one hand, that the dam had an arched floor plan in order to be able to better withstand the water pressure, and not just because the rock there provided the best building ground. And on the other hand, that the dam did not defy the flow by its sheer weight, as is the case with gravity dams, but by transferring the pressure forces from the abutments to the side walls of the gorge, which is made possible by the curvature of the lying arch .

Another arch dam known from antiquity stood near Glanum in France.

Modern exploration

A site survey in the late 1980s by the German scientist Günther Garbrecht raised the question of whether the dam described by Prokop was really an arch dam. Garbrecht was able to locate a location close to the ancient city walls, which in its essential characteristics corresponds to Prokop's precise description - with the exception of the arched floor plan of the dam.

The discovered dam, an approximately 4 m high and 5 m thick ashlar wall with a Roman concrete core , has an estimated crown length of 180–190 m; the central part has been completely destroyed over a length of 60–70 m. It cannot be ruled out that the dam once took a curved course in the area of ​​the wall breakthrough, but the wing walls that have been preserved indicate a polygonal floor plan. This would mean that the Dara dam withstood the water pressure by its own weight and not by arching. Garbrecht suggests that the irregular shape of the dam could have inspired Prokop to a poetic allusion to the crescent-shaped firmament . However, it should be pointed out that his observations on site did not meet the requirements of systematic hydrological and topographical investigations , which he warns in view of the creeping destruction of the ancient site.

Individual evidence

  1. ↑ Smith (1971), pp. 54f .; Schnitter (1987a), p. 13; Schnitter (1987b), p. 80; Hodge (1992), p. 92; Hodge (2000), p. 332, fn. 2
  2. ↑ a b c d Garbrecht & Vogel (1991), pp. 266-270.
  3. ↑ Smith (1971), pp. 54f .; Schnitter (1978), p. 32; Schnitter (1987a), p. 13; Schnitter (1987b), p. 80; Hodge (1992), p. 92; Hodge (2000), p. 332, fn. 2
  4. ↑ Smith (1971), pp. 53f.
  5. ↑ Garbrecht (2004), p. 130.
  6. ↑ Garbrecht & Vogel (1991), p. 270.

literature

  • Günther Garbrecht, Alexius Vogel: The dam walls of Dara. In: Günther Garbrecht (Ed.): Historical dams. Volume 2, Konrad Wittwer Verlag, Stuttgart 1991, ISBN 3-87919-145-X , pp. 263-276.
  • Günther Garbrecht: Procopius and the hydraulic structures of Dara. In: Christoph Ohlig (ed.): Hydraulic structures in the Kingdom of Urartu and other contributions to hydrotechnology in antiquity. Writings of the German Water History Society , Volume 5, Books on Demand, Norderstedt 2004, ISBN 3-8334-1502-9 , pp. 105-132.
  • A. Trevor Hodge: Roman Aqueducts & Water Supply. Duckworth, London 1992, ISBN 0-7156-2194-7 .
  • A. Trevor Hodge: Reservoirs and Dams. In: Örjan Wikander (Ed.): Handbook of Ancient Water Technology. Technology and Change in History, Volume 2, Brill, Leiden 2000, ISBN 90-04-11123-9 , pp. 331-339.
  • Niklaus Schnitter: Roman dams. In: Ancient World . Volume 8, No. 2, 1978, pp. 25-32.
  • Niklaus J. Schnitter: Directory of historical dams up to the end of the 17th century. In: Günther Garbrecht (Ed.): Historical dams. Volume 1, Konrad Wittwer Verlag, Stuttgart 1987, ISBN 3-87919-145-X , pp. 9-20.
  • Niklaus J. Schnitter: The history of the development of the arch dam. In: Günther Garbrecht (Ed.): Historical dams. Volume 1, Konrad Wittwer Verlag, Stuttgart 1987, ISBN 3-87919-145-X , pp. 75-96.
  • Norman Smith: A History of Dams. Peter Davies, London 1971, ISBN 432-151090-0 .

See also

Web links