Design, build, use – it may sound straightforward, but getting infrastructure right is a complex task. Value for money, time of construction and satisfying all involved, from investors, government bodies and end users, is a herculean effort. One project from from 2015, shows how, with the help of galvanized steel, it is possible to tick all these boxes and lead the way in infrastructure design into the bargain.
The construction of the new Vienna Central station helped centralise Vienna’s railway infrastructure. At a cost of €1 billion it was the biggest Austrian railway construction project of the day, bringing together the former South and East stations and Südtiroler Platz. The site covers nearly 50 hectares and extends to 6km. Since its completion, a new urban district has been created around it acting as a pivotal hub for the city’s transport network.
The lozenge roof of the new Vienna Central station was a worthy winner of the Austrian Steel Construction Prize. The roof structure, about six times the size of a football pitch, can be seen for miles around. It is one of the most complicated and beautiful steel construction projects in Austria and incorporates approximately 7,000 tonnes of steel.
Vibrant hub
Designed by Theo Hotz, partner Achitekten, and Unger steel, the new railway station has provided Vienna with a central hub in the trans-Europe rail network, which is used by more than 1,000 trains and by 145,000 people every day. The station’s spectacular steel and glass lozenge roof, 200 metres long and 120 metres wide, has become a symbol of modern mobility and functionality, and distinguishes the building from everything around it.
The roof structure, which is made up of 14 individual diamond shapes, arches over five platforms. Its height varies between six and 15 metres, so that it seems to hover over the platforms. Each individual rhombus consists of rods and nodes. The entire roof (including the forecourt canopy) is made up of more than 57,000 sections, 286,000 sheets of metal, and almost 340,000 screw fittings which are concealed beneath the cladding. The gigantic structure posed a superscale challenge for contractors and steel construction company Unger Steel, not only in terms of design and technology but also logistics.
Complex structure
A roof structure of this complexity meant that long term structural maintenance was not a option. Designers turned to galvanized steel to offer a reliable, zero maintenance solution that would stand the test of time. The ensuing design allowed for individual members to be galvanized and bolted together to form the complex rhombus for each subsection of the roof. This robust and effective approach means that ongoing maintenance is avoided alongside the costly delays and closures that this would encur. It also removes the additional health and safety complications that arise from working on structures of this scale.
The 14 diamond trusses of the station canopy each measure 76 metres and all are supported by solid twin supports every 38 metres. In the centre of the lozenge, the structure opens up to provide a skylight in the form of a crystal shaped opening measuring 6 x 30 metres. Integrated glass elements make it translucent and help to flood the building’s interior with daylight. At night, special lighting gives the roof a distinctive 3D effect.
Structural synonym
For the architect, the central station is more than an important traffic hub: “It’s a turntable in a Vienna which is open to Europe. The lozenge roof makes an important contribution to this as, with its dynamic design, its rhythm, and the way it seems to float in the air, it acts as a structural synonym for Vienna, the world-renowned city of music.”
The station now boasts over 200,000 daily commuters and is Austria’s busiest long-distance railway station. It has been voted Austria’s most beautiful station five times and has also come second for consumer choice ratings for rail stations in Europe.
Contact Galvanizers Association: +44 (0)121 355 8838
