More than a traffic hub: New cultural project comes to life under Vienna's Karlsplatz with the aid of TROSIFOL
After three years for construction, the busiest local public transport hub in Austria's capital has been resplendent in its new glory for about a year now. "Kulturpassage Karlsplatz" is the project and is much more than a means of interlinking metro stations – now barrier-free – so that over 200,000 travellers can get to their trains. "The main beneficiaries of this revitalisation project are the many thousands of users of the underground walkway. And Vienna as the city with the highest quality of life worldwide has been upgraded as well," says a gratified Mayor Michael Häupl.
A total of EUR 21 million has been invested in the regeneration of the old Karlsplatz station.
Art in public places
The designers attached special importance to the integration of the new Karlsplatz station in its environment of listed monuments. Karlsplatz, a public square, is situated in the centre of Vienna in the immediate proximity of numerous time-honoured art and cultural institutions such as the Opera House, the Vienna Museum, the Musikverein concert hall and the Karlskirche (church). "Art's ability to unite finds successful and literal expression in the new subterranean art walkway where it serves as a connecting element at the heart of the revitalisation project," says Andeas Mailath-Pokorny, head of the city's culture department. On the information screens provided, visitors to the underground walkway are informed not only of train departure times, but also of current exhibitions and events in the surrounding arts venues. In addition, "culture guidelines" have been marked on the floor and ceiling, leading the way with different-coloured, luminous stripes to the various institutions in the vicinity.
Europe-wide architecture competition
Karlsplatzpassage and Opernpassage, a listed monument, were refurbished after a Europe-wide architecture competition – while metro trains continued to run as usual. The goals were not only the preservation of existing monuments, but also an improvement in mobility at Vienna's key public transport hub, attractive design and enhanced visitor quality, ease of orientation combined with a stronger sense of safety and disabled access, and state-of-the-art building services and fire protection installations.
In addition to the widening and improved structuring of the walkway covering a total of 8,000 m², the architects came up with the idea of linking the walkway, as a lively urban space devoted to art and culture, with Vienna's world-famous cultural institutions in the immediate neighbourhood. In this way, visitors were to experience Karlsplatz as a focus of the arts, even underground. The aim was that the artworks should be easy to decipher at a fleeting glance and make a lasting impression.
At the same time, the monument-protected Opernpassage was to be restored to its original state and the historic structure refurbished to modern standards without impairing its historic character.
As one of 25 entries, a design by Viennese architects gerner°gerner plus and Ritter+Ritter in cooperation with the internationally active engineers Vasko+Partner won the competition (consortium "kulturpassage karlsplatz gerner°gerner plus | ritter+ritter | vasko+partner ingenieure").
The underground walkway linking the Opera House to Karlsplatz has become known colloquially as "Opernpassage". In fact, Opernpassage is confined to the area beneath the Opernring/Kärntnerstrasse junction. In 1955, the walkway designed by Adolf Hoch was opened as "part of the major development project to improve public road transport".
In the redesign of Opernpassage, great importance was attached to preserving the character of this listed structure as far as possible.
As a prelude to refurbishment, the original fabric was first investigated in order to free it of more recent modifications and restore it to its original state. "We researched how Opernpassage was originally fitted out by referring to numerous historic photographs – and this is how we arrived at the choice of natural stone for the floors and walls that is similar in appearance to the original floor surface," Gerda Maria and Andreas Gerner explain.
To their surprise, they discovered historic linoleum floorcoverings beneath the more recent polygonal marble slabs. In the course of historic refurbishment, the appearance of the original linoleum floorcovering was to be reinstated – but without using linoleum because of this material's poor compatibility with Austria's present-day fire protection standards. In terms of pattern and hue, the original floorcovering is delicately quoted by the coloured stone paving.
However, the monument preservation authority and architects had far greater problems finding a solution for the columns. The Gordian knot here was finally untied with the aid of printed TROSIFOL polyvinyl butyral (PVB) films. These come from Kuraray Europe GmbH, which is located in Germany and belongs to the Japanese Kuraray Group.
The printed pattern was derived from the professional photographs taken by gerner°gerner plus of the original linoleum surfaces dating back to the Nineteen Fifties. The photographs were printed onto the glass elements used for cladding the columns. The historic appearance has been restored visually to all the surfaces while modern safety requirements have been complied with at the same time. "The dark red is now in line with the guidelines of monument preservation and has brought some of the spirit of the Fifties back to Kulturpassage Karlsplatz," gerner°gerner plus explain.
In order to render the linoleum patterns printed straight onto the PVB film as accurately as possible, the architects chose 0.76 mm thick "Diamond White" TROSIFOL film. This is an opaque film in a powerful shade of highly reflective white. The Kuraray customer Eckelt Glas GmbH in Steyr, Austria, fabricated laminated safety glass by sandwiching this film between two six millimetre thick plies of curved white glass.
If all of today's regulations are to be complied with, there is obviously no better way of replicating the original. Friedrich Dahm, senior preservation expert at Austria's monument protection authority, expressed his satisfaction with the outcome in the newspaper DER STANDARD, 09/2013: "The historic core of Opernpassage has been restored in conformity with monument preservation provisions." In terms of colouration and pattern, the replicas on the films behind glass match the originals of 1955.
"Glass with its higher standards of fire safety than the original linoleum is very shiny and, unlike linoleum, reflects the lighting in its surroundings. In a design that makes do with a limited stock of materials, such supposedly incidental features really stand out," said Martina Frühwirth of the Vienna Architecture Centre at the beginning of the year.
Background to Kuraray and Business Area PVB
Worldwide, Kuraray is one of the leading manufacturers of PVB film and special films of established ionomer technology for the production of laminated safety glass. Products made of these films are used in applications for automotive and architectural glazing, and in the photovoltaic industry special films are used for durably encapsulating solar cells.
Business Area PVB is a division of the Kuraray Corporation domiciled in Tokyo, Japan, the world's market leader with polyvinyl alcohol (PVA), one of the key raw materials for TROSIFOL PVB films.
In Troisdorf, Kuraray Europe GmbH has installed an integrated and externally monitored management system that satisfies the requirements of DIN EN ISO 9001:2008 with the supplementary demands of the automotive industry ISO/TS 16949:2009, an environmental management system conforming to DIN EN ISO 14001:2009 and an occupational safety and health management system conforming to BS OHSAS 18001:2007.
Christoph Troska, Head of Marketing & Business Development
Kuraray Europe GmbH, Division TROSIFOL,
Mülheimer Strasse 26, 53840 Troisdorf, Germany
Phone +49 (0) 22 41 / 2555 201
Fax +49 (0) 22 41 / 2555 299