Eifel aqueduct
The Eifel aqueduct - also known as the Roman Canal or Roman Aqueduct to Cologne - was one of the longest aqueducts of the Roman Empire and is considered the longest aqueduct north of the Alps . The system supplied the Roman city of Colonia Claudia Ara Agrippinensium , ancient Cologne , with water for the public fountains , thermal baths and private house connections.
History of the line
The system had a predecessor, which is now called the Vorgebirgsleitung or better after its individual branches: Bachemer- (?), Gleueler-, Burbacher- and Hürther line (→ Roman water pipes in Hürth ). The strands of the previous line were archaeologically excavated between 1929 and 1953. They probably originated in different sections around 30 AD before the elevation of Ubierstadt to the Roman Colonia and used some springs and clean streams of the Ville mountain range (south) west of Cologne, in particular the Duffesbach or Hürther Bach . Before these streams were channeled by the Romans, they seeped away in the gravel of the Rhine. As the quantity and quality of water this line was no longer sufficient, the rapidly growing ancient to supply big city, although the sources even in the summer by the water stored in the Ville lignite layers sufficient bed had a new water line to sources in the was Eifel created. The lime-rich spring water from the Eifel was considered to be of particularly high quality.
This Eifel aqueduct was built around the year 80 AD from the northern Eifel from Opus caementitium and masonry made of natural stone. Although literary and epigraphic sources are lacking, it can be assumed with certainty that the leadership was established by the Roman army, as only this had the appropriate means. Its commander and governor of the associated army district, which a few years later became the province of Germania Inferior , was at this time Sextus Iulius Frontinus , who later became curator aquarum in Rome . Klaus Grewe , currently the best expert on the Eifel pipeline, suspects an obvious connection. The pipeline was 95.4 kilometers long and had a transport capacity of up to 20,000 cubic meters of drinking water per day. If you add the supply lines from the various sources , it was 130 km in length. In order for the construction to proceed quickly, the route was divided into construction lots . Grewe estimates the number at 20 sections that were tackled simultaneously. Two section boundaries were archaeologically proven by him in the sections that were not removed.
The pipe transported the water solely through its gradient and is a monument to the engineering art of that time, which still has an impact today. The course shows the ability of the Romans for exact measurements, the access to principles of physics and their practical implementation. Some mistakenly suspected the Iron Man in the Kottenforst as the measuring point of the line, which is presumably considerably younger.
The entire system was in operation until around AD 260; after the first sacking and destruction of Cologne by the Franks, it was not put back into operation. After this destruction, the rapidly flourishing town was supplied with water from the Duffesbach, which followed the canal route from Hermülheim. The previous status of the supply from the foothills was virtually given again. New investigations revealed that the line was damaged by earthquakes during its operating hours and then repaired.
Course of the line
The Eifel aqueduct begins in the Urft valley near Nettersheim am Grünen Pütz , where it took in the water from a spring . As a mere downhill line, it moved along the Urft valley slope to Kall in order to overcome the watershed between the Maas and the Rhine . The Roman engineers had found this one possible point in the area where the downhill pipeline could cross the watershed without a tunnel or pressure pipeline . The line then ran parallel to the northern slope of the Eifel, crossed the Erft near Euskirchen-Kreuzweingarten and the Swist with a brick arched bridge between Rheinbach and Meckenheim , and then passed the ridge of the foothills in the Kottenforst near Buschhoven , northwest of Bonn . The line finally reached Cologne via Brühl and Hürth . Other sources found in the Urft valley that met the requirements for water quality and quantity were also collected and fed.
Technical execution of the line
Most of the pipeline ran about 1 m below the surface of the earth to protect it from frost . The archaeological excavation cross-section shows a loose layer of stones at the bottom, on which mostly a U-shaped channel made of Opus caementitium (concrete) or masonry stones was placed. Then a layer of neatly hewn and mortared natural stone was built on the channel , which in turn supported a vault made of stones with a lot of mortar. For the execution in concrete and for the vault, boards were used for the formwork , the grain of which can be seen as an imprint in the concrete. The inside of the pipe itself was seventy centimeters wide and one meter high and could therefore also be accessed from the inside. It was plastered on the outside to protect it from ingress of water and, if necessary, was accompanied by a drainage system that kept groundwater and seepage water away from the pipe. The line crossed smaller watercourses with corresponding passages , one of which is still completely intact near the Grüner Pütz . The inside of the pipe was also provided with a reddish plaster ( opus signinum ), which consists of lime and aggregates such as crushed bricks . This plaster also hardened under water and sealed the pipe against water loss to the outside. Fine cracks and gaps in the plaster were sealed with wood ash , which was sprinkled in when the pipe was started up and filled with water for the first time.
Source versions
In addition to the already mentioned Green Pütz near Nettersheim, there were other spring catchments in the course of the pipeline. The Klausbrunnen near Mechernich -Kallmuth is best known, the well room of which was reconstructed after an archaeological excavation and provided with a protective structure. Further sources were collected, for example, in Mechernich- Urfey and fed into the pipeline. The construction of the wells was adapted to the local conditions and would also meet today's technical requirements.
The source areas in detail:
- The Green Pütz near Nettersheim ( 50 ° 30 ′ 45.7 ″ N , 6 ° 36 ′ 38.9 ″ E )
- The Klausbrunnen near Mechernich- Kallmuth ( 50 ° 33 ′ 9.5 ″ N , 6 ° 37 ′ 45.2 ″ E )
- The headwaters at Mechernich- Urfey
- The Hausener Benden headwaters near Mechernich- Weyer
The last-named spring area in particular is a specialty: In search of an abundant spring to supply Mechernich with drinking water, one came across a feeder from the Eifel aqueduct in 1938. The escaping water was then fed into the modern supply network. An archaeological search for the source was dispensed with in order not to endanger the source.
Demands of the Romans on water quality
The people of the Roman Empire preferred drinking water with high water hardness . Such drinking water is full-bodied than the bland tasting soft water, but it also tends to precipitate limescale within the transport lines. This Kalksinterablagerungen deposited as a dense layer on all areas of the pipe and prevented within the urban pipelines made of lead , that the toxic heavy metal could fall into the drinking water. Sinter layers also formed in the Eifel aqueduct itself, some of which reached a thickness of 30 cm during the operating period. Despite the associated narrowing of the cross-section , the pipeline was able to provide the necessary capacity for water transport without any problems. The lime precipitates themselves were used as so-called aqueduct marble as building material in later times.
The Roman architect and author Vitruvius names a method for testing a source for the production of drinking water :
“The testing and checking of the sources must be done as follows: If the sources spring up by themselves and are open to the surface, then, before starting the construction of the pipeline, look at and observe the structure of the people who live in the vicinity of these sources . If your physique is strong, your complexion is fresh, your legs are not sick and your eyes are not inflamed, then the springs will be excellent. "
Elsewhere with the same author you can find:
"Therefore, the sources must be sought and found with great care and effort with a view to the health of human life."
Buildings of the Eifel aqueduct
Only a few buildings were necessary for the Eifel aqueduct, none of them in the style of the Pont du Gard . Because the course of the line did not cross any large or deep valleys. The line was protected from frost underground (mostly on slopes) . So the water kept its pleasant cool on the way to Cologne.
To cross the Swist between Rheinbach and Lüftelberg , an arch bridge with a total length of 1400 meters and a height of up to 10 meters was built. The archaeologists assume that the bridge must once have had 295 arches with a clear width of 3.56 m. Only a low strip of rubble remains from the structure. An aqueduct bridge over the Erft between Euskirchen-Rheder and Euskirchen-Stotzheim had a length of approx. 500 m. Both bridges were completely demolished in post-ancient times to extract building material.
An arch bridge, the Aqueduct Bridge Vussem , crossed a side valley near Mechernich-Vussem at a height of about 10 meters and a length of 80 meters. The archaeological findings turned out to be unambiguous, so that a partial reconstruction of the bridge could be carried out in order to be able to give the visitor an idea of the structure.
In addition to these larger aqueduct bridges, there were also many small ones that were used to overcome streams. A well-preserved example of such a bridge is the aqueduct bridge in Mechernich-Vollem with only one passage or arch. A passage near Kall-Urft was used to overcome a dry valley that did not always carry water .
Behind the crossing of the Ville, aqueduct arches were placed on the old Hürth line . One section can be viewed in Hürth am Duffesbach ; accessible via the Vussemweg .
The Roman construction site
The construction of the line placed high demands on the skills and knowledge of the engineers involved . On the other hand, quality deficiencies in the building seem to have not been unknown to the Romans either, because Sextus Iulius Frontinus as the chief official of the municipal water supply in Rome wrote:
“No other building requires greater care in its execution than one that is supposed to withstand the water. Therefore, conscientiousness is required in all details for such a building - in keeping with the rules that everyone knows but only few follow. "
Effort to build the line
A structure of this length could not be realized in one go in terms of surveying , civil engineering and masonry work. Instead, the Roman engineers, who must have belonged to the legions stationed on the Rhine border, divided the entire construction site into individual construction lots . Modern archeology is methodically able to determine the limits of such construction lots. Construction lots with a length of 4440 meters each were found in the Eifel aqueduct, which is almost exactly 15,000 Roman feet . It was also possible to prove that the survey was carried out completely independently of the construction of the line. In this context, the construction of the line will have proceeded in a similar way to that which is still common today on large construction sites . The construction work is estimated with an excavation of 3 to 4 cubic meters per running meter of pipe, plus 1.5 cubic meters of masonry and concrete as well as 2.2 square meters of plaster to seal the pipe. The total effort is estimated at 475,000 daily work , with 180 effective days of construction per year around 2500 workers would be employed for 16 months. However, the actual construction time will have been significantly longer, as this calculation does not include the measurement or procurement of the building materials . After the completion of the system or its sections, the excavation pit was filled up again, the surface leveled and a path laid out for the line attendants, who regularly inspected the route . This path also marked a protective strip within which agricultural use of the site was prohibited. Similar facilities are also known from other aqueducts. On the Roman aqueduct to Lyon , the Gier aqueduct , the archaeologists found a prohibition sign with the following inscription:
"At the behest of the Emperor Caesar Trajanus Hadrianus Augustus, no one is permitted to plow, sow or plant within the space that is intended to protect the water pipe."
Roman surveying technology
In addition to the sensible location of the line in the field, the necessary gradient of the line had to be guaranteed. With their Chorobates , spirit level-like measuring devices, the Roman engineers were able to maintain a gradient of one per thousand , so the line overcame a height of one meter at a distance of one thousand meters. Added to this was the need, on the borders of the individual building lots a forced point having to adhere to the height, because at a construction line down one encountered at some point at the beginning of the next batch, which was begun by Nachbarbautrupp. The line was therefore not allowed to get too deep at this constraint point. The Roman builders used the available gradient accordingly carefully and sparingly. On the other hand, if the pipe got too high at this point, a small stilling basin in the pipe was sufficient to calm the falling water.
Roman concrete as a building material
The Roman builders used a mixture of burnt lime , sand, stones and water with hydraulically acting additional aggregates as a kind of concrete, which was tamped between the excavation pit as external formwork and an internal formwork made of boards. Samples of this material have been subjected to modern tests; It turned out that the concrete would have easily met today's standards for this building material. In the literature, the name Opus caementitium is also used for this building material .
Operation of the line
During its probably 180-year service life from 80 to around 260 AD, the line had to be constantly maintained, repaired, cleaned and sintered . For this purpose, inspection shafts were installed at regular intervals , from which the line could be accessed. Sometimes the inspection shafts were also created over repair sites and the boundaries of the construction lots. At the merging of the individual spring strands, similarly designed open basins were created so that the maintenance staff could always keep an eye on such problem areas.
To remove impurities and suspended matter from the fresh water, sedimentation basins were used with skillful use of the reduction in flow velocity . This can be demonstrated at least in the first operating phase of the previous building, the Hürther pipe, before the Eifel water pipe is connected to it. This technology also increased the water quality. Such a basin was excavated during road construction work on Berrenrather Strasse in 1927. It can be viewed there. Coin finds in this facility suggest that it was used from around the year 50 onwards. When the Eifel aqueduct was connected, this basin was built over with the aqueduct.
Distribution of water in the ancient city of Cologne
In the last kilometers before the ancient city, the pipe left the ground and led the water over an aqueduct bridge, which reached a height of about 10 meters in front of the city. The reason for this additional construction effort is the need to be able to supply higher-lying parts of the city with penstocks . The pipes of that time consisted of lead plates that were rolled into a ring and soldered together at the joints of the ring . In addition, flanges were also used to connect the individual pipe sections. As fittings the Romans used cocks from bronze . The incoming water then flowed primarily into the city's many public fountains, which were constantly in operation. The network of running wells was so dense that no resident of the city had to go further than 50 m to one of these wells. The management also supplied thermal baths , private house connections and the public toilet facilities . The wastewater was washed into the Rhine through a network of canals located in the Cologne underground . A piece of these sewer pipes can still be viewed and walked under the Budengasse in Cologne today.
Use of the line as a quarry
In the year 260, the line was destroyed by a warlike attack by the Teutons and was not put back into operation, although the Roman city of Cologne continued to exist. In addition, knowledge about the aqueduct was later lost in the turmoil of the Great Migration . The complex initially remained untouched in the ground for half a millennium, until new construction work began in the Rhineland during the Carolingian era . During this time, the pipeline was thoroughly exploited in the stone-poor Rhineland. For example, fragments that could just be transported were broken out of the pipe and, for example , walled up again in the Rheinbach city wall . Sometimes the plaster used to seal the pipe still adheres to these chunks of concrete. In this way, all high-rise buildings and large parts of the underground facilities were completely removed and given a new use.
The so-called aqueduct marble , a sintered lime , as the already explained lime precipitate was also called, was particularly popular . During the service life of the pipeline, this material had accumulated in a layer of rock up to 30 cm thick. The material has the appearance of brownish to reddish colored marble and could be easily removed from the cross section of the pipe. The sintered lime could be polished without further ado and, due to the accumulation of calcite minerals, was given a texture in the longitudinal direction that looked like the grain of wood, while at right angles , against its natural bed, it appeared like a petrified board. The rare natural stone was in great demand throughout the Rhineland; columns , window reveals and even altar plates were made from it. The material can be found in the east as far as Paderborn and Hildesheim , where it was installed in the local domes . The northern distribution even extends as far as Denmark in Roskilde Cathedral , where the sinter, also known as Eifel marble , was used in the form of grave slabs; there is also an aqueduct marble column in Sweden's oldest stone church in Dalby .
In the popular belief of the Middle Ages, the Eifel water pipeline became an underground pipeline from Trier to Cologne, as is clear from the Cologne cathedral statement - the devil bet the cathedral builder that he could complete this pipeline faster than the builder of the Cologne cathedral . The builder took up the bet and urged his people to hurry. One day the builders came across an underground stream of water while excavating for Cologne Cathedral. The devil's gleeful giggles drove the cathedral builder to his death: He fell from the half-finished cathedral towers into the depths. His death was seen as the cause of the centuries-long standstill of the Cologne Cathedral construction site.
In some cases, the original purpose of the aqueduct was reinterpreted so much that it did not transport water but wine - for example in the Gesta Treverorum of St. Maternus (4th century) and in the Annolied (11th century).
Final scoring
Archaeological research into the Eifel aqueduct did not begin again until the 19th century. The Mechernich mountain official CA Eick deserves the credit of having recognized the well room of the Grüner Pützes as the farthest source from Cologne as early as 1867 . The line was systematically researched from 1940 to 1970 by Waldemar Haberey . His text, published in 1971 (see selection of literature), is still a useful guide along the route. The archaeologist Klaus Grewe , employed by the Rhenish State Office for Monument Preservation, has completely mapped the route since 1980 and entered it on the German basic map . His "Atlas of the Roman Aqueducts to Cologne" is regarded as the standard work on research into Roman aqueducts.
The Eifel aqueduct presents itself as a technical monument of the first order, on which the Roman surveying , the Roman organizational skills and the skills of the Roman engineers can be studied. It is indicative of the loss of technical knowledge that after the destruction and decay of the plant, the following generations could no longer do anything right with the line and used it as a quarry. The Roman state of the art in the field of water supply was not reached again until the 19th and 20th centuries. Thus, the entire complex, which is considered to be worth preserving, has a role model function.
Tourist notices
The “Römerkanal-Wanderweg” (Roman Canal Hiking Trail), which was renewed in 2012, leads along the route of the aqueduct from Nettersheim via Kall , Rheinbach , Brühl and Hürth to Cologne . The 7-stage route has 53 stations with detailed information boards about the sights and gives a very good idea of the course of the pipeline route . The hiking trail is approx. 115 km long and, thanks to the dense network of local public transport, can be walked in several stages or even driven by bike . A Freundeskreis Römerkanal, in which all residents and responsible institutions are members, takes care of the further maintenance and marketing of the building. He also organizes his own exhibitions and events.
See also
- Roman Canal hiking trail
- Green Pütz
- Exposure of the Eifel aqueduct with a passage at Kall-Urft
- Klausbrunnen
- Aqueduct bridge in Mechernich-Vollem
- Collection basin in Eiserfey
- Vussem aqueduct bridge
- Aqueduct bridge over the Erft
- Aqueduct bridge over the Swist
- Roman water pipes in Huerth
literature
- CA Eick : The Roman aqueduct from the Eifel to Cologne with regard to the Roman settlements, fortifications and military roads that were initially located. A contribution to antiquity in the Rhineland. With a card. Max Cohen & Son, Bonn 1867.
- Klaus Grewe : Atlas of the Roman water pipes to Cologne (Rhenish excavations, Volume 26) . Rheinland-Verlag, Cologne 1986. ISBN 3-7927-0868-X .
- Klaus Grewe: Eifel water pipeline. In: Heinz Günter Horn (Ed.): The Romans in North Rhine-Westphalia. Licensed edition of the 1987 edition. Nikol, Hamburg 2002, ISBN 3-933203-59-7 , pp. 409-418.
- Klaus Grewe: Aqueduct marble. Lime sinter of the Roman Eifel aqueduct as a building material of the Middle Ages. In: Bonner Jahrbücher 191, 1991, pp. 277–343.
- Klaus Grewe: New findings on the Roman water pipes to Cologne. Supplements and additions to the "Atlas of the Roman water pipes to Cologne". In: Bonner Jahrbücher 191, 1991, pp. 385-422.
- Klaus Grewe: The Römerkanalwanderweg . Eifelverein, Düren 2005. ISBN 3-921805-16-3 .
- Klaus Grewe, Manfred Knauff: The long leadership of the Romans. The Römerkanal hiking trail Nettersheim-Cologne. Publisher: Eifelverein e. V. 1st edition 2012. ISBN 978-3-921805-81-7 .
- Klaus Grewe: Aqueducts. Water for Rome's cities. (Accompanying volume to the exhibition “Aqueducts - Water for Rome's Cities” in the Museum of Bathing Culture, Zülpich.) Regionalia Verlag, Rheinbach 2014. (Part A General information on the construction and technology of Roman water pipes with many references and examples on the Cologne pipe, Part B, p . 240–392: Eifelwasserleitung), ISBN 978-3-95540-127-6 , review:.
- Waldemar Haberey : The Roman water pipes to Cologne. The technology of supplying water to an ancient city . Rheinland-Verlag, Bonn 1972. ISBN 3-7927-0146-4 .
- Waldemar Haberey: The Roman Eifel aqueduct to Cologne. In: Northeastern Eifel foreland - Euskirchen, Zülpich, Bad Münstereifel, Blankenheim. Part I: Introductory essays (= Römisch-Germanisches Zentralmuseum Mainz et al. [Hrsg.]: Guide to prehistoric and early historical monuments. Volume 25). Verlag Philipp von Zabern, Mainz am Rhein 1974, pp. 69-85.
- Werner Hilgers : Vussem, aqueduct . In: Walter Sölter (Ed.): The Roman Germania from the air . Gustav Lübbe Verlag, Bergisch Gladbach 1983, ISBN 3-7857-0298-1 , p. 242f.
- Rudolf Pörtner : With the elevator to Roman times . Moewig, Rastatt 2000 (also other editions). ISBN 3-8118-3102-X .
- Ingrid Retterath: Germany: Roman Canal hiking trail . Conrad Stein Verlag, Welver 2008. ISBN 978-3-86686-240-1 .
Movie
- Roman Eifel aqueduct - the Roman canal from Nettersheim to Cologne. Documentary, Germany, 2017, 5:09 min., Script and director: Norbert Conzen, production: Rhein-Eifel.TV, series: Museen & Römer , Internet publication : March 25, 2017 on YouTube, online video and synopsis , with Klaus Grewe.
Exhibitions
- Aqueducts - water for Rome's cities. Zülpich , Römerthermen Zülpich - Museum of Bathing Culture , March 22, 2014 - October 12, 2014.
- Aqueducts - water for Rome's cities. Xanten , LVR-RömerMuseum , December 10, 2015 - June 18, 2017.
Web links
literature
- Karl Naske: The Roman aqueduct. In: woenge.de
- Georg May: The Roman Canal in the Sötenich district. In: soetenich.de
- Klaus Grewe : Book List
trail
- Klaus Grewe: Roman Canal Hiking Trail (PDF)
- Roman Canal hiking trail in the Hürth area. In: City of Hürth
- Mechernich-Kallmuth: the “Klausbrunnen” well with a new look. In: LVR Office for Monument Preservation in the Rhineland , 2013, (PDF; 1.6 MB)
- Roman aqueduct from Nettersheim to Cologne. In: NRW Foundation , 2013
various
- Image of a reconstructed section of one of the bridges of the aqueduct
- List of 600 Roman aqueducts, 25 of which are documented in detail. (English)
Individual evidence
- ↑ Klaus Grewe (Rh. Office for Land Monument Preservation, Bonn): Nine sections of the Roman Eifel aqueduct to Cologne recovered, in: Hürther Heimat , Heft 65/66, Hürth 1990, ZDB -ID 400272-6 , p. 113 f.
- ↑ Interview with Grewe on the opening of the hiking trail ( Memento from March 5, 2016 in the Internet Archive )
- ↑ Grewe, aqueducts , p 58, with reference to Grewe, Atlas .. .
- ^ Hoffmann, G., Kummer, S., Márquez, R., Valdivia Manchego, M .: The Roman Eifel Aqueduct: archaeoseismological evidence for neotectonic movement at the transition of the Eifel to the Lower Rhine Embayment . Ed .: International Journal of Earth Sciences. doi : 10.1007 / s00531-019-01766-y .
- ^ Vitruvius : De architectura libri decem 8,4,1.
- ^ Vitruvius: De architectura libri decem 8,3,23.
- ^ Sextus Iulius Frontinus : De aquaeductu urbis Romae 2, 123.
- ↑ a b CIL 13, 01623 (4, p 22)
- ↑ Gerta Wolff : Das Römisch-Germanische Köln , 6th revised edition, Cologne 2005, ISBN 3-7616-1370-9 , pp. 265-269.
- ↑ Klaus Grewe, Manfred Knauff: The long leadership of the Romans. The Römerkanal hiking trail Nettersheim-Cologne. 2012.
- ↑ Inga Thulfaut: "Water for cities of Rome". Klaus Grewe presented his book for the exhibition of the same name. In: General-Anzeiger (Bonn) , March 13, 2014.
- ↑ Water for Rome's cities - exhibition worth seeing. In: Rhein-Eifel.TV , 2014, with online video , 3:34 min., In it Klaus Grewe.
- ^ Water for Rome's cities. In: LVR-RömerMuseum , 2015; Leaflet , (PDF; 178 kB).
Coordinates: 50 ° 30 ′ 45.7 ″ N , 6 ° 36 ′ 38.9 ″ E
