Nussdorf weir and lock system

The weir system with the Schemerl Bridge, the former administrative building for the “Danube Regulatory Commission”, the so-called “chain magazine building” (far right), a small power station and a fish pass

The weir and lock system in the Nussdorf district of Vienna is a hydraulic structure at the point where the Danube Canal branches off from the Danube . It was built on the basis of the law of July 18, 1892, enacted by the Reichsrat , regarding the implementation of public transport facilities in Vienna .

The law regulated the financing of the construction of the Vienna light rail , the conversion of the Danube Canal into a trading and winter port , the regulation of the Vienna River and the construction of collecting canals along the two rivers. Political agreements followed between the Cisleithan government, the crown land of Austria under the Enns, and the Vienna city administration.

Since 2005 the weir has been used to generate energy by means of a small power station and since April 2017 fish can cross the weir using a fish ladder .

location

The name of the buildings does not match the district affiliation. Nussdorf is part of the 19th district and the closest place; Most of the components are located in Brigittenau , which was still part of the 2nd district during the construction of the facilities, but was spun off from this as the 20th district in 1900. The district border runs on the western, Nussdorf bank of the Danube Canal.

In common parlance, the Nussdorf weir and the Nussdorf lock are often equated with each other, although they are two separate structures whose construction, however, served a common purpose.

Nussdorf weir, administration building and Schemerl bridge

Seen from Nussdorf, the buildings are located at the rear of the Nussdorf train station of the Franz-Josefs-Bahn .

Predecessor structure

Before the weir and lock system in Nussdorf was built, the floating gate constructed by Wilhelm Freiherr von Engerth protected the Danube Canal above all from drift ice and largely also from floods. After the completion of the Nussdorf weir, the floating gate, which had previously protected the Danube Canal, remained in service until the First World War. It was only scrapped in 1945.

Nussdorf weir and lock system

The weir and lock system in Nussdorf and the Kaiserbadwehr were the only hydraulic engineering structures that were implemented for the realization of the planned port in the Danube Canal. The two other planned weir and lock systems were to be built at the Ostbahnbrücke and directly in front of the Freudenau harbor .

The construction of this facility was necessary in order to protect the new buildings on the Danube Canal (light rail, collecting canals and later the harbor with the ships) from floods and ice rushes , but on the other hand to let enough water into the canal for shipping. The floating gate by Wilhelm Freiherr von Engerth provided the protection against ice bursts satisfactorily, but it was very difficult to regulate the amount of water flowing in. Mainly because of the collecting canals built along the Danube Canal, the water level was only allowed to rise by 80 centimeters.

Nussdorf weir

The double truss bridge with three main walls as a structural part of the weir

The Nussdorf weir was built between August 1894 and 1899. The masonry was completed in 1897 and the steel structure was assembled by Albert Milde in August 1898 . The administration building and the chain store followed in 1899. As artistic advisor to the Commission for Transport Systems in Vienna , Otto Wagner worked out the plans for the architectural design of the weir with the Schemerl Bridge, its ancillary buildings and (possibly) the lock system, while the technical planning came from Siegmund Taussig . Due to the exposed location - at the junction of the Danube Canal from the Danube to the city center of Vienna - Otto Wagner saw the weir he designed (technically a "needle weir", but also a "bridge weir") as a city gate and accordingly equipped it with powerful pylons who carry bronze lion figures by Rudolf Weyr . These lions were the model for the Gräf & Stift company logo .

Closed weir during the floods in 1899

The Nussdorf weir passed its first endurance test during the floods of 1899, when the areas on the Danube Canal were prevented from being flooded.

To open and close the weir system, some tracks with a gauge of 1690 mm were laid, on which material for the weir system was transported with work cars and electrically powered tractors.

In the course of improvements to the Danube flood protection, the needle weir was replaced between 1971 and 1975 by a modern segment weir, consisting of the weir and the gates (liftable and lowerable locks of the weir system, which can be lowered to the bottom of the water). Between 2004 and 2005, the Nussdorf power plant was built below the weir system without any externally visible changes to the overall historical appearance. 12 turbines produce around 28 gigawatt hours per year and thus cover the electricity needs of around 10,000 households. This joint project was realized by Wien Energie , EVN and Verbund-Austrian Hydro Power AG (AHP) .

Schemerl Bridge

The Schemerl Bridge

This bridge, also known as the “Lion Bridge”, was named after Joseph Schemerl von Leythenbach (1752–1844), Imperial Councilor and Hofbauratsdirektor, who in 1810 worked out a (unrealized) project to regulate the Danube.

The name of the bridge is given in different spellings:

In the Provincial Law Gazette for Vienna No. 34/1996, the “Josef-von-Schemmerl-Brücke” is mentioned in the definition of the new district boundary between the 19th and 20th district.
According to the “Official Vienna Street Directory - 16th updated edition”, it is the “Schemmerl Bridge”.
The inscription on one of the pylons reads "Schemerl Bridge".
Various city maps of Vienna name this bridge either as "Josef von Schemerl Bridge" or "Schemerl Bridge".

The book “Querungen.” Published by the municipal department responsible for bridges, MA 29. Bridges - City - Vienna ”writes in the included directory of Vienna bridges from the“ Schemerl Bridge ”; since this spelling matches that of the namesake, it can be assumed that this is the correct name.

The bridge, built as a truss bridge between 1894 and 1898, with its 49 meters span spans not only the 40 meter wide water passage but also the nine meter wide stairway . Its construction was important for the weir system for structural reasons, because the three main girder walls and the strong horizontal girder absorbed the water pressure and the weight of the bridge (for this reason the weir is also known as a bridge weir), which is why it was also used as a double truss bridge three main walls erected. But it was also needed for the technical operation of the weir system.

In April 1945, like the other Danube Canal bridges, it was blown up and rendered unusable. In 1947, a wooden footbridge was first built to enable pedestrians to cross the Danube Canal. The war damage was repaired between 1953 and 1955 and in 1978 a thorough renovation took place.

The lion as the hood ornament of vehicles from the Vienna automobile factory Gräf & Stift was modeled on the lion on the Schemerl Bridge designed by Rudolf Weyr . The City of Vienna allowed the factory to use it in 1916.

In 2018, on the 100th anniversary of Otto Wagner's death, the Schemerl Bridge was chosen as the motif for the annual European stamp of the Republic of Austria, a special stamp with a face value of 80 cents.

Nussdorf lock

The Nussdorf lock

Construction of the Nussdorf lock also began in August 1894. Not only was the chamber lock 85 meters long and 15 meters wide, but the canal 20 meters wide, about 3.5 meters deep and with an embankment slope of 1 was also to be built : 2½, which made their use possible in the first place. This canal made it necessary to build two railway bridges for the Danube shore line and a road bridge (“Nussdorfer Schleusenbrücke”) for the connection between Nussdorf and Handelskai . It is unclear whether this lock was also designed by Otto Wagner and how it survived the Second World War. From 1964 to 1966, the hand-operated miter gates, which opened from the side, were replaced. On November 25, 1966, the town hall correspondence announced that on this day City Councilor Kurt Heller handed over the fully mechanized system, equipped with lifting and swivel gears manufactured by VÖEST .

In order to supply the lock chamber with enough water even when the circulation channels were blocked with ice, a maintenance channel was built. The lock is still in operation today and is also used on boat tours that circle the entire Danube Island (2nd and 20th district).

Administration building

The former administration building of the weir and lock complex in Nussdorf, today the seat of the Municipal Department 45 - Vienna Waters

The former administration building of the Danube Regulatory Commission, now Danube Flood Protection Competition (DHK), (address: 20., Am Brigittenauer Sporn 7), built next to the Nussdorf weir with the Schemerl Bridge according to plans by Otto Wagner, is a three- story secessionist building. On the protruding roof is a roof attachment that served as an observation station. Since June 2017, the building has been the seat of the Municipal Department 45 - Vienna Waters, responsible for Vienna's waters and flood protection .

Chain magazine

The chain magazine of the weir and lock system in Nussdorf

The chain store is located south of the administration building and is designed as a one to two-storey building.

power plant

The small power station by the weir and the fish ladder canal at the bottom left

In 2005 a small power plant was put into operation, which consists of 12 Hydromatrix turbines with a total output of 4.8 MW.

Fish ladder

The fish pass or staircase was built in 2016/2017 on the left bank of the weir and was carried out in accordance with the requirements of the EU Water Framework Directive and the National Water Management Plan . It connects the habitats of the Danube Canal and the Danube and makes the weir accessible for the fish. The project was a cooperation between DHK (Danube Flood Protection Competition) and the partners of the Nussdorf joint power plant. The total cost of the fish ladder amounted to 6.4 million euros. Commissioning took place in April 2017.

literature

Danube Regulation Commission in Vienna: The weir and lock system in the Vienna Danube Canal near Nussdorf . Vienna 1911, from the kk Hof- und Staatsdruckerei
Bertrand Michael Buchmann u. a .: The Danube Canal - history-planning-execution . Magistrate of the City of Vienna, Vienna 1984
Raimund Hinkel: Vienna on the Danube. The great river, its relationship with the city and the development of shipping through the ages . Christian Brandstätter Verlagsgesellschaft mbH, Vienna 1995, ISBN 3-85447-509-8
Walter Hufnagel (Editor: MA 29 - Bridge Construction - Foundation Construction, City of Vienna): Crossings. Bridges - City - Vienna . Verlag Sappl, Kufstein 2002, ISBN 3-902154-05-5