Jentower
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Jentower Intershop Tower, Uniturm |
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| Jentower | |
| Basic data | |
| Place: | Jena , Germany |
| Construction time : | 1970-1972 |
| Renovation: | 1999-2001 |
| Status : | Built |
| Architectural style : | Modern |
| Architect : | Hermann Henselmann |
| Use / legal | |
| Owner : | Saller commercial building |
| Main tenant: | Intershop Communications |
| Technical specifications | |
| Height : | 144.5 m |
| Height to the top: | currently 159.60 m |
| Floors : | 29 upper floors |
| Usable area : | 23,000 m² |
| Height comparison | |
| Jena : | 1. ( list ) |
| Germany : | 21. ( list ) |
| address | |
| City: | Jena |
| Country: | Germany |
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The Jentower (own spelling JenTower ) is a high-rise in Jena . With a height of 144.5 m (with antenna tip 159.60 m) it is the tallest office building in the new federal states according to the official height (without technical superstructures).
It has 31 floors, including 2 basement floors and 29 upper floors. The tower is built using a sliding formwork method on a 3.20 m thick reinforced concrete floor slab . The diameter is 33 m. The curtain glass facade contains 56 windows per full storey, a total of 1456 windows. The net floor area is around 23,000 m². Connected to the building is a shopping center with around 6000 m² of retail space and an underground car park with 200 parking spaces. The Jentower is currently (June 2008) owned by Saller Gewerbebau.
history
In the 1960s, the Council of Ministers of the GDR decided to accelerate the construction and redesign of important cities in the country. So-called “city dominants” should give historical city centers a new, “socialist” appearance and tower above all other buildings, especially the church towers. The state architect Hermann Henselmann was commissioned to design a round tower for Jena, which was supposed to symbolize a telescope . The building was to be used as the research center of the Carl Zeiss Jena combine .
In June 1969, the historic residential and business district around Eichplatz , which had been spared from the Second World War, was demolished in order to gain building space for the planned round tower. The foundation stone was laid on April 30, 1970. Between June and September 1970, the reinforced concrete core was built using the sliding formwork method. For cost reasons, the building could only be implemented in a reduced version of the original Henselmann design.
The high-rise was inaugurated on October 2, 1972. Since there was no longer any need for use by the Carl Zeiss combine, the building was handed over to the Friedrich Schiller University of Jena for use.
After 1995 the university left the tower. The now vacant building was put up for sale by the owner, the State of Thuringia . Saller Gewerbebau GmbH won the bid for the symbolic purchase price of DM 1.
Fundamental renovation work began in 1999. The old facade was demolished and replaced by a new curtain glass facade. The base was demolished and replaced by a new building. At the Leutragraben, an underground car park and a frame building with 5 floors were built. The tower received two additional floors as well as an antenna structure and thus reached a height of 149 m in 2001. After the tower antenna was raised in 2004, the Jentower is currently 159.60 m high and thus currently the tallest building in the eastern federal states, measured by the clearance height .
use
The tower is mainly used as an office building. The main tenant with around half of the space is Intershop Communications AG , which has its headquarters here. Other companies from the IT sector have settled in the company's environment, some of which emerged from Intershop.
Other tenants are Deutsche Effecten- und Wechsel-Beteiligungsgesellschaft , IKS Garamond Verlag and ePages . The 27th floor was converted into a hotel by the end of 2012 and, with a height of 120 m, is the second highest hotel in Germany within a building. On the 28th and 29th floors there is a restaurant that is open every day and a public viewing platform. On the 29th floor there are transmission systems from several cell phone operators that use the building's antenna system.
In the subsequent plinth conversion with the name "Neue Mitte" there are mainly retail stores.
Surname
The building is referred to by a variety of names. Official names are Jentower and Intershop Tower. In colloquial terms, however, the anglicisms are rarely used; the building is often referred to as the Uniturm, Intershop Tower, "biscuit roll" or simply "the tower".
Surroundings
Directly opposite the Jentower to the west is the former factory premises of the VEB "Carl Zeiss Jena" with Building 59 designed by Henselmann as a research high-rise for Carl Zeiss Jena , followed by the first German high-rise, 43 m high Building 15 , which was built in 1915 according to plans the architect Friedrich Pützer (1871-1922) was built. Building 36 (today the headquarters of Jenoptik AG) is located further to the west .
In the north are parts of the more than 700 year old city wall, with the Johannistor , the only completely preserved city gate of Jena, and the powder tower .
Double tower
Rumors of an originally planned, but never executed twin tower, which are identical in construction and connected to the completed structure by a bridge, are persistent around the tower and thus represent binoculars as a symbol of the optical device construction, which is strongly represented in the city of Jena. Research by historians at the Friedrich Schiller University of Jena at the beginning of the 1990s did not confirm this rumor, but early designs provided for two more, somewhat smaller towers on the grounds of the Collegium Jenense , which were to be connected by a crossbar.
These fell victim to the red pen, as did the round windows of the main tower originally planned by Henselmann, which should have been reminiscent of optical lenses and its “crown” (a metallic ring at the top of the tower).
Facade damage
At the end of 2004, parts of a pane of the tower's glass cladding came loose and smashed the rear window of a car in the adjacent parking lot. First, as part of the investigation into the causes, individual elements of the cladding were dismantled and examined for errors. According to the result of an expert opinion, inclusions of nickel sulfide caused the toughened safety glass to break . This meant that all rows of the tower, which only contain cladding elements and no windows, were completely surrounded by a net to prevent further panes from falling.
literature
- Michael Diers (1999): The Tower of Jena. Architecture and characters. (= Minerva. Jenaer Schriften zur Kunstgeschichte, Volume 9), Jena: Kunsthistorisches Seminar, 181 pp.
- Christian Graudenz (2007): On the history of the development of the university high- rise from 1968 to 1972. In: Uwe Hoßfeld, Tobias Kaiser, Heinz Mestrup (eds.): University in Socialism. Studies on the history of the Friedrich Schiller University Jena (1945–1990) , Volume 1, Weimar a. a .: Böhlau, 2007, pp. 339–376.
- Antje Schneider, Robert Vogler (2008): The Tower of Jena. Multi-perspective exploration didactics using the example of Jena city center. In: Praxis Geographie, Issue 7–8, pp. 10–14.
See also
Web links
- Jentower. In: Structurae
- Building owner's website
- Website of the main tenant with numerous facts about the building and its history
- Webcam from the tower
Individual evidence
- ↑ Jentower at CTBUH
- ↑ History of the Jentower
- ↑ Scala Jena: Second highest hotel in Germany opened in Jena. Jenaer Nachrichten, accessed on March 30, 2013 .
- ↑ ( page no longer available , search in web archives: regioweb.de )
- ↑ Research on the "Tower of Jena". Retrieved June 9, 2020 .
- ↑ http://www.otz.de/startseite/detail/-/specific/Glasbruch-an-Thueringens-hoechstem-Turm-1411116942
- ↑ http://www.baunetzwissen.de/standardartikel/Glas_Spontanbruch-von-ESG-durch-Nickelsulfid-Einschluss_159350.html
Coordinates: 50 ° 55 ′ 44 " N , 11 ° 35 ′ 4.7" E