Otto Intze

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Otto Intze, wood engraving after a photolithography from 1898
Bronze plaque at the Urfttalsperre
Otto Intze grave, Vaals

Otto Intze (born May 17, 1843 in Laage , Mecklenburg ; † December 28, 1904 in Aachen ; full name: Otto Adolf Ludwig Intze ) was a German civil engineer and university professor . He taught as a professor for hydraulic engineering , building construction and building materials at the Technical University of Aachen , of which he was also rector from 1895 to 1898.

Life

Intze's father was a general practitioner and enabled his son to attend a technical school at a secondary school. After successfully completing his degree, Intze got a job at the age of 17 for a British company that built a railway line from Riga to the interior of the country in Russia, now in Latvia. After two and a half years of activity, he began a broad-based engineering course at the Hanover Polytechnic in autumn 1862 , which he completed in 1866 as the best of his year.

He then briefly worked as a teacher at the Holzminden building trade school before moving to the Hamburg port administration, where he was in charge of the construction of bridges, quay walls and locks. In this position he felt secure enough to raise a family. In the summer of 1868 he married Charlotte Emilie Theodore Lorenz, with whom he had four sons and four daughters.

When August von Kaven, who was one of Intze's teachers in Hanover as a professor of road and railroad construction, set up a “ polytechnic school ” in Aachen for the then Prussian Rhine Province , he brought him to the new institute as a lecturer for building construction and hydraulic engineering. In the year it opened, 1870, Intze was appointed professor at the age of 27. His wandering life came to an end and Intze's first factory buildings were built in Aachen in the 1870s, including for the Lochner cloth factory and the Ritz & Vogel cloth factory . Although he later received appointments at the technical universities of Braunschweig, Berlin and Munich, he stayed in Aachen for the rest of his life.

Intze was instructed to also work as a freelance engineer in order to establish a close connection between theory and practice. He mastered an immense workload in both areas. Still fully employed, he fell seriously ill in autumn 1904. He did not recover and died on December 28th.

Intze was a devout Lutheran . Since there was no Protestant church in Catholic Aachen at that time, he attended the service in the neighboring Dutch town of Vaals. Otto Intze found his final resting place with his wife in the Nieuwe Hertogenweg cemetery in Vaals.

Elevated water tank

Salbker water tower built according to the Intze principle
1904 built water tower with pump wind turbine and Intze tank near Schweckhausen

Intze was one of the first to recognize the benefits of steel for the construction of water tanks on towers. They were increasingly needed because the cities built a public water supply and the steam locomotives also had to be refueled from elevated tanks. By means of a new design - the containers designed by Intze were bevelled at the bottom and had no flat bottom, but an upwardly curved bottom - he achieved that the horizontally acting forces offset each other. This allowed the tank to be stored on a relatively narrow circular ring, which in turn made the load-bearing tower slimmer and cheaper.

According to this patented principle (the first Intze principle , water tower # Intze container ), a total of 467 water and 74 gas containers were built in Germany, as well as in the rest of Europe and overseas, the first of which in 1883 in Remscheid . In addition, around 30 factory buildings were built under Intze's direction; He also designed air central heating systems for large buildings and built a dozen iron water wheels for small industries in the Eifel.

Dams

The Intze wedge named after Otto Intze
Eschbach dam
Möhne reservoir
Construction of the Urft Dam in 1903

That would have been enough as a life's work, but Intze's achievement, which goes beyond that and has an impact to this day, is the foundation of modern water management in Germany. He was based on France, where a large number of dams with a total capacity of 265 million cubic meters had already been built. At the 23rd Annual General Meeting of the Association of German Engineers (VDI) in Magdeburg in 1882, Intze presented a program for the "rational use of Germany's hydropower". In his first project that was implemented, the focus was not on the use of hydropower, but on the water supply.

In 1884 the city of Remscheid put a waterworks with a groundwater well into operation, which soon no longer sufficed for the increasing demand for water. Intze suggested building a dam. To do this, he first had to get an idea of ​​the amount of water available. He therefore constructed an automatic level station working with a clock mechanism and had the precipitation measured at two points in the catchment area at the same time . He was able to deduce that around three quarters of the precipitation flowed through the Eschbach and that an average of 3.6 million cubic meters of water was to be expected every year.

According to Intze's calculations, a storage space of one million cubic meters was sufficient to secure the city's water supply and to provide sufficient drive water to the factories in the valley. For this purpose, the Eschbach had to be dammed by 25 meters. Intze designed a quarry stone wall that tapered from the base to the crown and was arched to the water side. Brick by hand brick by brick, it was completed after three years in 1892. All other Intze dams were built according to this pattern, the second Intze principle .

Intze was called to the Wupper while the work on the Eschbach dam was still in progress. In some years the factories were idle for four or five months due to a lack of water. He was able to prove that collecting basins in the upper reaches could raise the summer low water to three times the amount. However, individual water users blocked the project. A law on the formation of compulsory cooperatives removed this obstacle in 1891 and the project could be implemented. This means that the storage volume of all dams has already reached a total of 13 million cubic meters. But that was just a prelude to a far bigger project. The task was to secure the water supply in the Ruhr area .

Although mining and industry had expanded from the Ruhr north to the Emscher in the second half of the 19th century, the area continued to rely on the water from the Ruhr because the Emscher was completely polluted by sewage and the wells as a result of the lowering of the groundwater stopped giving water through mining. Towards the end of the 19th century, water abstraction from the Ruhr reached more than 100 million cubic meters per year and it was foreseeable that the river would dry up in summer if consumption continued to rise.

Based on studies by Intze, cities and industry founded the Ruhrtalsperrenverein in 1899 . With a water fee of 1.5 pfennigs per 10 cubic meters, considerable funds flowed into a fund, and according to Intze's plans by 1904, no fewer than seven dams could be built on the upper reaches of the Ruhr and its tributaries. After his death, the work continued. Under the direction of Ernst Link , one of his assistants, the 135 million cubic meter Möhne Reservoir was built, which by far exceeded all storage space created up to that point.

Parallel to the work on the Ruhr, the administration of the Prussian Rhine province commissioned Intze to carry out investigations into flood protection on the Rur in the Eifel . He realized that due to the topography, flood protection could be combined very cheaply with the use of hydropower . The Rur meanders, rapidly losing height, in a deeply cut valley through the Eifel. With a power plant, not at the foot of the dam, but downriver, a considerable difference in altitude could be used via a relatively short tunnel that cuts off the river loops. Intze found the best place for a dam on the Urft tributary . From there, a gradient of 110 meters was gained over a 2.6 kilometer long tunnel to Heimbach . The power plant had a maximum output of 12 megawatts, making it the most powerful in Europe for a short time.

The Urfttalsperre is a 58 meter high arch dam that tapers from 50 meters at the base to the crown to 6 meters. At the side there is an overflow, over which the flood plunges into the depths during high tide. Including the preparatory work, the construction lasted from 1899 to 1904. In the summer up to 800 workers were employed, mainly from Italy, Croatia and Poland.

At the same time Intze was active in distant Silesia . The tributaries of the Oder from the Giant Mountains suffered severe flooding in 1888 and 1890 and again in the summer of 1897. Kaiser Wilhelm II therefore urged measures to be taken against the risk of flooding. As a member of a committee, Intze toured the affected areas and submitted relatively detailed proposals for dam projects as early as February 1898. By giving a lecture to the technology-loving emperor, he was able to win his support and was also appointed a member of the Prussian mansion for life . This enabled Intze to have a decisive influence on the course of things on a political level.

In July 1900 the Silesian Flood Protection Act came into force, which, as proposed by Intze, also provided for the construction of two large dams on the Bober and Queis . The facilities at Mauer ( Pilchowice ) and Marklissa ( Leśna ) were linked to hydroelectric power stations, as was the case with the Urft Dam. The final elaboration and completion of the projects was in the hands of building officer Curt Bachmann, a Hirschberger employee of Intzes.

Just like Silesia, Bohemia was hit by floods in 1897 on the upper Görlitz Neisse . Intze, who was involved in the planning, designed six more dams. In the middle of this work he died.

Up to this point in time, eleven dams had been built under Intze's direction, twelve more were under construction and the same number were in different studies of planning and preparation.

Intze dams built before the First World War

Barrier wall of the Sengbach dam
Memorial plaque for Intze's 100th birthday at the Mšeno dam

Between 1889 and 1914, a total of over 40 new dams were built throughout the German Empire and Austria-Hungary according to Intze's personal designs or the Intze principle (nine of them in Westphalia , seven in the Bergisches Land , seven in Saxony , six in Bohemia , four in Silesia , two in the Eifel and one in Thuringia ).

The following list is sorted by time of completion:

The following dams were planned with the help of Intze, but they are dams and not dams based on the Intze principle:

Control tower of the broken dam on the White Desse

Intze dams built after the First World War

The following dams were completed after the First World War according to Intze's plans or built according to the Intze principle:

The Intze dams today

Hennetalsperre around 1900

In view of dam disasters in other countries, Intze placed the highest demands on the safety of the structures. So he made sure that the walls were always built a few meters deep into the natural rock. The masonry was usually made of rubble from solid rocks. Intze paid particular attention to the composition of the mortar. He used a mixture of lime, sand and trass , a volcanic rock from the Eifel. Trass contains silicic acid and as a result a silicic acid , particularly solid lime forms when it hardens. That is why trass from the Eifel was even used for the dam walls in Silesia.

On the water side, the wall was arched so that the inevitable changes in length due to temperature and pressure fluctuations could be better balanced out and no cracks formed, which has been observed repeatedly in dam walls in France. On the water side, the walls were provided with a 2.5 centimeter thick cement plaster and a multiple coat of tough tar was applied to it for further sealing. Water that penetrated the masonry in spite of everything should be collected and drained off in walled-in drainage pipes made of clay. A one and a half meter thick layer of clay and loam was attached to the foundation and covered with earth. This "Intze wedge" was intended to prevent water from penetrating the foundation and the wall from being raised by the so-called " bed water pressure ".

Intze was convinced that his precautions would make the walls “last forever”. But despite all the care, leakages of more or less large size occurred after several decades. The Hennetalsperre on a tributary of the Ruhr, which Intze had already referred to as his “child of pain” during the construction period due to the difficult geological conditions, was abandoned and demolished in 1949 because the dammed, carbonated water had attacked the dam wall and hollowed out the limestone bedrock.

The dam on the White Desse , which Intze was involved in the planning shortly before his death, broke on September 18, 1916, one year after its completion , due to insufficient sealing, war-related material shortages and planning errors such as insufficient attention to the subsoil. This accident resulted in 62 deaths. Today only the control tower and a connecting tunnel to the neighboring Darretalsperre remain of this dam.

A general inspection in the period around 1980, which was required due to new DIN standards , revealed that there were considerable groundwater pressures in almost all walls. Not only had the Intze wedge proven to be largely ineffective, but also due to the overgrown rock, which was not taken into account in Intze's time, considerable water pressures had built up. This made a fundamental rehabilitation of the dams inevitable. Various measures were used depending on the type of defects. The walls were sealed with concrete shells or tear-resistant plastic sheeting, cement was injected into the subsoil, or the water pressure under and in the wall was reduced by drainage tunnels. In the course of the renovations, extensive equipment with measuring instruments was also carried out.

The cost ranged from 3 to 30 million euros, depending on the size of the wall and the type of damage. This means that the 100-year-old Intze walls are well equipped for safe operation for another century.

Honors

In 1893 the city of Remscheid made Intze an honorary citizen . In addition, Intzestrasse and Intzeplatz in Remscheid-Süd were named after Intze. 1902 awarded him the Technical University of Dresden , the honorary doctorate (Dr.-Ing. E. h.). When he was appointed to the Prussian mansion, Intze was appointed a secret building officer. In 1894 he was awarded the Grashof Memorial Medal by the Association of German Engineers . Numerous monuments, busts and memorial plaques throughout Germany honor Intze's life's work, for example:

  • the Intze bust at RWTH and
  • the memorial plaque on Intzeplatz in Remscheid.

Trivia

  • In Wroclaw were in 2002 during the renovation of the building of the former Technische Hochschule Breslau rediscovered nine portrait medallions important on the facade of the main building technicians, engineers and scientists, among them Otto Intze. The medallions were created in 1927 by the sculptor and art historian Kurt Bimler , who taught at the Institute of Architecture at the Technical University of Wroclaw until 1945 . The attachment of the medallions is related to the expansion and expansion of the university between 1925 and 1928.
  • In the town of Laage, there has been a memorial plaque on Intze's birthplace at Breesener Strasse 21 since 1937. The birth house was extensively renovated in 2004.
  • In Aachen there is a student residence built in 1966 in the form of a high-rise, the Otto-Intze-Haus (OIH) [1] , and an Intze-Strasse that is named after him.
  • Water towers in the Intze design still exist in Oberhausen (1897), Essen-Steele (1897), Berlin-Hohenschönhausen (1901/1902), in Berlin-Spandau (1907) and Eilenburg (1916, tanks in reinforced concrete ).

Fonts

  • Efficient use of water power in Germany. In: Weekly of the Association of German Engineers 1882, No. 41.
  • The waterworks of the city of Düren and more recent water towers, oil and gas containers. Berlin 1886.
  • The better use of water and water power. Berlin 1889.
  • The water conditions in East Prussia. Berlin 1894.
  • Expert opinion on the utilization of considerable water power through the Masurian Shipping Canal . Berlin 1896.
  • Answer to question B posed in the Very Highest Decree of February 28, 1892: "Which measures can be applied to prevent the risk of flooding and flood damage as much as possible in the future?" For the Oder river area, Bober and Queis. 1898.
  • The better use of water and water power. Reprint from the journal of the Association of German Engineers, Berlin 1889.
  • About the water conditions in the mountains. Hanover 1900.
  • Development of the dam construction in Rhineland and Westphalia until 1903. Aachen 1903.
  • The historical development, the purposes and the construction of the dams. In: Journal of the Association of German Engineers, 50th year 1906, No. 18.

literature

  • Siegfried Clodius: Professor Intze, Aachen. A pioneer of German dam construction. Yearbook of the Eifelverein 1959, Bonn 1959. pp. 54–56.
  • Richard Hennig : Book of Famous Engineers. Leipzig 1911.
  • Wolfgang König : The engineer as a politician. Otto Intze, dam construction and flood protection in the Oder catchment area . In: Technikgeschichte Vol. 73, 2006, H. 1, pp. 27-46.
  • Heinz-Dieter Olbrisch:  Intze, Otto. In: New German Biography (NDB). Volume 10, Duncker & Humblot, Berlin 1974, ISBN 3-428-00191-5 , p. 176 f. ( Digitized version ).
  • Hans-Dieter Sauer: Otto Intze (1843–1904). The founder of the German dam construction. In: Civil Engineering in Germany, Yearbook 2007/2008, Hamburg 2008.
  • Exhibitions in the university library on the occasion of the 125th anniversary of the Technical University of Aachen. Aachen, 1996, pp. 74f.
  • Oskar Schatz: Otto Intze (1843-1904) , in: Rheinisch-Westfälische Wirtschaftsbiographien, Volume VI. Aschendorff, Münster 1954, pp. 60–80.
  • Energy and hydropower. On the 100th anniversary of Otto Intze's death. (Proceedings of the 35th IWASA, International Hydraulic Engineering Symposium Aachen 2005.) (= Chair and Institute for Hydraulic Engineering and Water Management, Rheinisch-Westfälische Technische Hochschule Aachen, Mitteilungen, No. 142.) Shaker, Aachen 2005, ISBN 3-8322-4286 -4 .
  • Obituary for Otto Intze . In: Journal of the Association of German Engineers, 49th year 1905, No. 4.
  • Otto Intze † . In: Zentralblatt der Bauverwaltung, Volume 25, 1905, No. 3 (January 7, 1905), pp. 14-16.

Web links

Commons : Otto Intze  - collection of images, videos and audio files

Individual evidence

  1. ↑ The RWTH on old postcards and drawings. In: www.aachener-geschichtsverein.de. Retrieved May 6, 2020 .
  2. ↑ https://www.rga.de/lokales/remscheid/flattern-wimpel-wind-5300560.amp.html. In: www.rga.de. July 29, 2015, accessed May 6, 2020 .
personal data
SURNAME Intze, Otto
ALTERNATIVE NAMES Intze, Otto Adolf Ludwig
BRIEF DESCRIPTION German engineer and university professor, professor of hydraulic engineering, building construction and building materials theory at RWTH Aachen University
DATE OF BIRTH May 17, 1843
PLACE OF BIRTH Laage
DATE OF DEATH December 28, 1904
Place of death Aachen