---
title: Technik und Architektur
---

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## Insight into  Engineering & Architecture

The **Donauturm** is not only **Vienna’s tallest structure** but also an **architectural and technical masterpiece**. Since its **opening for the Vienna International Garden Show in 1964 (WIG 64)**, it has impressed visitors with its **innovative design, advanced engineering, and timeless aesthetics**.

From the **express elevators** that transport guests to the top in just **35 seconds**, to the **rotating platforms** in the **restaurant and café**, and the **sturdy construction** that withstands even **strong winds**—the tower showcases **decades of engineering excellence**.

Discover the **fascinating history** behind the **architecture and technology** of this landmark, and explore the **modern innovations** that continue to make the **Donauturm one of Austria’s most impressive structures** today!

## The Structural Elements of the Donauturm

![Bauteile c Rennhofer](https://info.donauturm.at/hubfs/Audioguide/Technik/Bauteile%20c%20Rennhofer.jpg)

### Elements - Foundation

**1. The Foundation – A Stable Base**

At the very bottom, the **massive foundation** ensures the **stability** of the Donauturm. It supports the entire **structure** and secures the tower against **wind and vibrations**.

(c) Rennhofer

![07-Rohbau180](https://info.donauturm.at/hubfs/07-Rohbau180.bmp)

### Elements- Tower Shaft

**2. The Tower Shaft – The Slim Core**

The **slim concrete shaft** extends upwards and supports the **main areas** of the tower—including the **observation deck, café, and restaurant**.

![09-Plattform040](https://info.donauturm.at/hubfs/09-Plattform040.jpg)

### Element- Tower Head

**3. The Tower Head – Where Everything Rotates**

At the **top section**, the **tower head** houses the **rotating platforms** of the **restaurant and café**. Here, visitors can enjoy the **spectacular 360° view**.

![BF1_0870](https://info.donauturm.at/hubfs/BF1_0870.jpg)

### Element - Steel Mast

**4. The Steel Mast – The Tower’s Crown**

At the **very top** of the **tower shaft**, the **steel mast** extends into the sky, bringing the Donauturm to its **final height of 252 meters**. This is also where **logos and technical equipment** are mounted.

![Herstellung des Fundamentss-1](https://info.donauturm.at/hubfs/Audioguide/Technik/Herstellung%20des%20Fundamentss-1.jpg)

### The Foundation – The Stable Base of the Donauturm

**1 | Shallow Foundation Instead of Deep Foundation**

Instead of a **deep foundation**, a **shallow foundation** was chosen, as the **ground was stable enough** to support the structure. This not only **saved costs** but also **sped up construction** significantly.

![Grundriss des Fundaments c Rennhofer](https://info.donauturm.at/hubfs/Audioguide/Technik/Grundriss%20des%20Fundaments%20c%20Rennhofer.jpg)

### The Foundation – The Stable Base of the Donauturm

**2 | An Extraordinary Design**

The **foundation** is not a simple **concrete block** but a **circular ring** with an **outer diameter of 31 meters** and an **inner diameter of 10 meters**. It is **buried about 8 meters underground**.

(c) Bernhard Rennhofer

![Lastableitung der Vertikalkräfte Rennhofer](https://info.donauturm.at/hubfs/Audioguide/Technik/Lastableitung%20der%20Vertikalkr%C3%A4fte%20Rennhofer.jpg)

### The Foundation – The Stable Base of the Donauturm

**3 | Perfect Load Distribution**

Thanks to its **three different shell structures**, the **foundation evenly distributes** the **massive weight** of the Donauturm, ensuring **maximum stability**.

(c) Bernhard Rennhofer

![223_donaupark-10_span-12 Quelle WStLA](https://info.donauturm.at/hubfs/Audioguide/Technik/223_donaupark-10_span-12%20Quelle%20WStLA.jpeg)

### The Foundation – The Stable Base of the Donauturm

**4 | Built in Record Time**

The **foundation was completed in just two months**—allowing construction of the **tower shaft** to begin as early as **October 11, 1962**.

![04-Rohbau090](https://info.donauturm.at/hubfs/Audioguide/Technik/04-Rohbau090.bmp)

### The Tower Shaft – The Heart of the Donauturm

**1 | A Slim Reinforced Concrete Tube**

The **tower shaft** is a **182-meter-high** tube made of **reinforced concrete**, anchored into the **foundation**. Its **diameter tapers** from **12 meters at the base** to just **6 meters** from a height of **145 meters**.

![Rohbau](https://info.donauturm.at/hubfs/Audioguide/Technik/Rohbau.png)

### The Tower Shaft – The Heart of the Donauturm

**2 | Strong Yet Lightweight**

The **wall thickness** decreases from **50 cm at the base** to just **25 cm at the top**, reducing **weight** without compromising **stability**.

![Donauturm_Doppeldeckkabine](https://info.donauturm.at/hubfs/Audioguide/Technik/Donauturm_Doppeldeckkabine.jpg)

### The Tower Shaft – The Heart of the Donauturm

**3 | Two High-Speed Elevators**

Inside the tower, **two elevators** transport visitors to the **observation deck** in just **35 seconds**. The **elevator shaft** begins in an **“E” shape** and transitions into a **“T” shape** above **65 meters**.

![230_der_donauturm-8_span-12 Quelle WStLA](https://info.donauturm.at/hubfs/Audioguide/Technik/230_der_donauturm-8_span-12%20Quelle%20WStLA.jpeg)

### The Tower Shaft – The Heart of the Donauturm

**4 | Record-Breaking Construction with Slipform Technology**

Instead of using **traditional scaffolding**, the **tower was built using slipform construction**. The **concrete was poured in sections**, and the formwork was **continuously raised**, allowing the tower to grow **4 to 5 meters per day**.

![Herstellung des Turmes im Winter 1963 Matthias Schmitt](https://info.donauturm.at/hubfs/Audioguide/Technik/Herstellung%20des%20Turmes%20im%20Winter%201963%20Matthias%20Schmitt.jpg)

### The Tower Shaft – The Heart of the Donauturm

**5 | Harsh Conditions in Winter 1962/63**

A **severe winter** halted construction for **two months**. At **150 meters high**, freezing temperatures and strong winds made work difficult. **Heaters and straw mat covers** were used to **protect the concrete from frost**.

(c) Matthias Schmitt

![Querschnitt Turmschaft](https://info.donauturm.at/hubfs/Audioguide/Technik/Querschnitt%20Turmschaft.png)

### The Tower Shaft – The Heart of the Donauturm

**6 | Completion on February 28, 1963**

Despite these **challenges**, the **tower shaft** was completed in just **a few months**. By **February 28, 1963**, the **foundation of the Donauturm** was finished—allowing the **assembly of the observation deck** to begin!

(c) Bernhard Rennhofer

![Grundriss der Aussichtsterrasse](https://info.donauturm.at/hubfs/Audioguide/Technik/Grundriss%20der%20Aussichtsterrasse.png)

### The Tower Shaft - The Observation Deck

Instead of being **circular**, the **observation deck**, mounted **150 meters above ground**, has the shape of an **equilateral triangle**.

Its **support structure** consists of **24 steel radial beams**, resembling a **truss framework**. These beams were lifted to the **top of the tower** using a **small crane** and were directly **attached to the shaft**. After installation, they were **encased in concrete at both ends**—and to this day, these **embedded beams** remain **visible on the underside of the deck**.

(c) Bernhard Rennhofer

![Querschnitt Turmkopf](https://info.donauturm.at/hubfs/Audioguide/Technik/Querschnitt%20Turmkopf.jpg)

### The Tower Head – Engineering Meets Spectacular Views

**1 | Architecture & Function in Perfect Harmony**

The **tower head** is the **centerpiece of the Donauturm**, seamlessly combining **architecture with sophisticated technology**. It houses not only the **restaurant and café** but also **practical facilities** such as a **central kitchen and restrooms**.

(c) Bernhard Rennhofer

![Querschnitt Drehbühne](https://info.donauturm.at/hubfs/Audioguide/Technik/Querschnitt%20Drehb%C3%BChne.jpg)

### The Tower Head – Engineering Meets Spectacular Views

**2 | The Unique Rotating Mechanism**

To ensure that **all guests enjoy the best possible view**, a **rotating platform** was developed. Instead of **facing just one direction**, the entire **restaurant and café floor rotates** around the tower.

(c) Bernhard Rennhofer

![Antrieb Drehbühne](https://info.donauturm.at/hubfs/Audioguide/Technik/Antrieb%20Drehb%C3%BChne.jpg)

### The Tower Head – Engineering Meets Spectacular Views

**3 | How Does the Rotation Work?**

The **rotating platform** rests on a **steel framework** that moves on **special rollers**. These **rollers drive the platform**, allowing it to **rotate independently**, without affecting the **tower shaft**.

(c) Matthias Schmitt

![Donauturm_Panorama 7](https://info.donauturm.at/hubfs/Bilder/Donauturm/Donauturm_Panorama%207.jpg)

### The Tower Head – Engineering Meets Spectacular Views

**4 | Three Different Speeds**

The rotation operates at **three speeds**:

**Fast:** One full rotation in **22.5 minutes**  
**Medium:** One full rotation in **26 minutes**  
**Slow:** One full rotation in **45 minutes**

![Donauturm_Panorama 6](https://info.donauturm.at/hubfs/Bilder/Donauturm/Donauturm_Panorama%206.jpg)

### The Steel Mast – The Crown of the Donauturm

**1 | More Than Just a Design Element**

The **steel mast** at the **top of the Donauturm** is not just a **visual landmark**—it also serves an **important function**. In addition to the **prominent logos**, it houses a **police radio system** and various **weather instruments**.

![Detailansicht Stahlmast Rennhofer](https://info.donauturm.at/hubfs/Audioguide/Technik/Detailansicht%20Stahlmast%20Rennhofer.jpg)

### The Steel Mast – The Crown of the Donauturm

**2 | Height & Tapered Structure**

The **70-meter-high mast** tapers towards the top, similar to the **tower shaft**:

**Base diameter:** **2.50 meters**  
**Remains constant up to 232 meters**  
**Narrows to just 1 meter at the top  
**

The **sheet metal thickness** also varies, from **18 mm at the base** to just **8 mm at the top**.

(c) Bernhard Rennhofer

![Montage Stahlmast Matthias Schmitt](https://info.donauturm.at/hubfs/Audioguide/Technik/Montage%20Stahlmast%20Matthias%20Schmitt.jpg)

### The Steel Mast – The Crown of the Donauturm

**3 | A Technical Challenge During Installation**

Instead of **lifting the mast as a single piece**, it was **assembled in sections** using a **crane** and **welded at the top of the tower shaft**. A **special working platform** extended beyond the **observation deck**, allowing the **safe transport and installation** of the mast sections.

(c) Matthias Schmitt

![Blechstreifen Rennhofer](https://info.donauturm.at/hubfs/Audioguide/Technik/Blechstreifen%20Rennhofer.jpg)

### The Steel Mast – The Crown of the Donauturm

**4 | Smart Design to Reduce Wind Oscillations**

The **tip of the steel mast** is equipped with **sheet metal strips in a spiral shape**. These help to **minimize vibrations caused by strong winds**, ensuring **stability** even in **extreme weather conditions**.

(c) Bernhard Rennhofer

## Explained by Bernhard Rennhofer

## What no one sees – but everyone feels

![Donauturm_MR](https://info.donauturm.at/hubfs/Audioguide/Technik/Donauturm_MR.jpg)

### Warmth at High Altitudes – A Challenge of the Past

As early as the 1960s, **heating **the gastronomy areas at 160 and 170 meters posed a remarkable **technical challenge.** Wind, cold, and the rotating platforms demanded creative solutions. Warm air was channeled through central ducts to the upper levels – an innovation that made it possible to dine comfortably in the Turm Restaurant, even during winter.

![doc06159020201008145201_001](https://info.donauturm.at/hubfs/Audioguide/Technik/doc06159020201008145201_001.jpg)

### Rotating Comfort Zones

Heating the rotating café and restaurant levels was particularly demanding. Special air ducts in the base zone transported warm air to the moving platforms. The technology at the time was sophisticated – but with rising expectations for energy efficiency and comfort, it eventually reached its limits.

![Hoval Heizung](https://info.donauturm.at/hubfs/Audioguide/Technik/Hoval%20Heizung.jpg)

### Hoval Delivers Cutting-Edge Heating Technology

In 2017, the heating system was completely modernized. Two **Hoval **Max-3 gas boilers now deliver reliable warmth with 700 kW of output, controlled by the intelligent TopTronic E system. A heat exchanger system supplies the rotating platforms with 80°C warm air – efficient, robust, and future-ready. Even at sub-zero temperatures, it's pleasantly warm 170 meters above the ground.

- 35
  
  
  
  
  
  ##### Seconds
  
   Duration of one trip
- 514
  
  
  
  
  
  ##### Tons
  
   Reinforcing steel were installed
- 126
  
  
  
  
  
  ##### Metres
  
   smaller is the Vienna International Center
- 80
  
  
  
  
  
  ##### Kilometres
  
   Long distance view in fair weather
- 6
  
  
  
  
  
  ##### Marriage Proposals
  
   Average per week
- 20
  
  
  
  
  
  ##### Months
  
   lasted the construction

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## The most beautiful workplan in Engineering

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## Window replacment in the Turm Restaurant at 170m

- 252
  
  
  
  
  
  ##### Metres
  
   Austria´s tallest Structure
- 17600
  
  
  
  
  
  ##### Tons
  
   Weight of the Tower
- 12
  
  
  
  
  
  ##### Metres
  
   Diameter Ground
- 6
  
  
  
  
  
  ##### Metres
  
   Diameter at 160m
- 31
  
  
  
  
  
  ##### Metres
  
   Depth of Foundaition
- 779
  
  
  
  
  
  ##### Stairs
  
   counts the Staircase

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## Annual Window Cleaning

**Heritage Protection  
**As one of Vienna’s most famous landmarks, the Donauturm has been under heritage protection since 2001. The 2018 renovation was carried out in close coordination with the Federal Monuments Office.

**Weather Monitoring Station**  
Since 1964, weather stations on the observation deck have been measuring temperature, humidity, and wind speed. The Institute of Physics also monitors CO₂ levels and aerosols.

**Environmental Measurements**  
The Donauturm enables the monitoring of atmospheric changes up to 200 meters high. Since 1969, it has also measured carbon monoxide and hydrocarbons, providing key data for Austria’s Air Quality Act.

**Broadcasting Mast**  
The steel mast houses FM transmission systems for radio stations like Radio Arabella & 98.3 Superfly. The Donauturm is also an important site for mobile networks and police radio communications.

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## Technology tour

**Aviation Beacon**  
Since 1965, the Donauturm has served as a navigation point for aircraft. A blinking light system assists with safe landings at Vienna Airport, especially in poor weather conditions.

**Storm Resistance**  
Even during the strongest storms, the Donauturm remains stable. At the very top, it sways only 1.25 meters, while the restaurant and café move by just 30 cm—a true engineering masterpiece!

**Lightning   
**Lightning strikes have been common since its opening, but guests in the restaurant or café experience them only as a brief flicker in the lighting.

**Heating System**  
Two high-performance gas boilers and an innovative warm-air base heating system ensure maximum comfort—even in winter and on the rotating platforms.

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## Report on Industrial Climbing (2007)