Vienna: Juggling much-needed renovation with no service interruption

Many passengers on the U6 are not aware of the fact that their daily journeys are along sections of track some of which are almost 120 years old. Back in 1898, the emperor of the Austrian-Hungarian monarchy opened the former urban railway as a pioneering public transport line for the fast-growing metropolis on the Danube which was the capital of the Habsburg Empire. Today, six of the stations on the U6 hail from the time when massive steam locomotives still chugged through the city. The electrification of the urban railway took place in 1924/25 and allowed the maximum speed of the trains to increase to 40km/h. The conversion of the historical urban railway to establish the U6 line took place from around 1980. This project also involved allowing barrier-free access and installing further safety and information-based features as well as adapting the stations to the requirements of underground train operation. The work carried out also entailed building continuous concrete track beds on the arches. But even then attention was paid to maintaining the core of the listed buildings and integrating these structures into the new underground line. The opening of the U6 underground line took place in 1989 and involved a switch to driving on the right, with the historical urban railway route forming the backbone of the new underground line. In the mid-1990s, the U6 line was extended in a number of additional phases until it ultimately operated along its current route. Despite all of the modernisation steps and conversion work, the U6 remains the only underground line in Vienna which is supplied with electricity via overhead power lines rather than a conductor rail and therefore relies on rolling stock which is different from that operating on other lines in the city.

Stations classified as listed buildings

It is no surprise that stations built around 120 years ago require considerably more maintenance work than modern structures. Several of the stations also still bear hidden scars from bomb damage during the Second World War. The damage incurred was provisionally rectified after the end of the war in order to be able to resume operations rapidly. The former urban railway stations built by Otto Wagner form part of the historical and cultural heritage of Vienna and are classified as listed buildings. This status applies to the U6 stations Gumpendorfer Straße, Burggasse, Josefstädter Straße, Alser Straße, Währinger Straße and Nußdorfer Straße. As listed buildings, this means that the outer appearance of the buildings has to be maintained. Modernisation work is only possible in close consultation with the Austrian National Heritage Agency. Complying with the listed-building requirements is one of the major challenges involved in renovating these historical stations. The requirements entailed by the status as a listed building have to be aligned with state-of-the-art technology (fire protection, accessibility, etc.) as well as the need to maintain the structure of the building (easy-to-clean surfaces, etc.) and the requirements for regular underground train services.

A major revitalisation programme has been ongoing for several years in order to make the historical U6 stations built by Otto Wagner fit for the decades ahead. At the same time, however, the aim is also to adapt the buildings to the requirements of modern underground line services which allow trains to operate at two-minute intervals during peak times. Modern underground standards mean, for example, the installation of tactile guidance systems for passengers with reduced visibility on platforms and in other areas, modern passenger information systems, video surveillance cameras, but also of course technical installations such as those relating to power supplies and building technology. The first project started in 2011, focussing on the U6 station Josefstädter Straße. The work took over two years to complete and led to further renovation projects on other historical stations. In 2013, the historical station building and the platforms of the U6 station Burggasse were renovated. Since 2014 and following an intensive period of planning and preparation, the work to renovate the Alser Straße station has been ongoing. In total, Wiener Linien is investing around €15 million in the complete renovation of the station building. The aim of this wholescale renovation project is also to ensure that the costs of maintenance work in the coming years are kept as low as possible. Wiener Linien decided to engage in this major project and, as a result, also to avoid having to renew the roofs and then the facades of the building after the necessary renovation of the platforms. The extensive nature of this project is bringing the entire station building up to date.

No service interruption during major renovation work

Around 30,000 passengers use the Alser Straße station on the U6 during a normal working day. Hundreds of trains stop at the station every day at intervals of just a few minutes. The aim of Wiener Linien is that renovation work is conducted in such a way that the inconvenience for passengers is kept to a minimum. It was for this reason that Wiener Linien elected to renovate the platforms at Alser Straße one at a time rather than simultaneously. For a period of around five months, only one of the platforms was out of service, with trains in the relevant direction passing through the station without stopping while the other platform remained in service as usual. The work was organised in such a way that it was always possible for the station to remain open. Despite the ongoing building work, this considerably reduced the inconvenience caused to passengers. Wiener Linien made a point of informing passengers early about the necessary work and pointing out alternative routes. During the five months that the platforms were alternatively out of use the main areas of the relevant half of the station were renovated and renewed. The old platforms were removed piece by piece and replaced with new ones. The new platforms include integrated damp protection which now prevents water penetrating the walls and causing damage as it had done in the past. As aboveground stations, the former urban railway stations are permanently exposed to the wind, rain and snow, which had led to water seeping into their structural elements and causing moisture damage. An important step was the refitting of the historical tiles originally put in place at the time of Otto Wagner and responsible for giving the stations their unique character. A tactile guidance system which is standard in modern underground construction work was integrated into the tiling, making it easier for visually impaired passengers to navigate the station. Both systems have also been installed in the main transit area of the station. The steps from the main transit area to the platforms were also removed and replaced in the course of the renovation work, as was the entire roof over each platform. The lighting was upgraded to be based on energy-saving LED bulbs, new display panels were adapted in line with the modern design of the underground system and cameras for video surveillance were also installed. Every step, every detail – even the colour of the paint for the door frames – has to be coordinated with the Austrian National Heritage Agency and every change relative to the original condition of the building has to be negotiated. The historical supports of the roof over each platform had to be restored in painstaking manual work, as did the windows and doors. It goes without saying that the walls and the facade were also renovated in the course of the project. And all of this was carried out without interrupting operations and with only minimal inconvenience caused to passengers. One particular challenge was maintaining the outer appearance of the station. The use of white paint was imposed as a requirement due to the building’s listed status despite the fact that this colour is particularly difficult to keep clean and, as a result, the new stations already showed major signs of dirt only a few weeks after being painted. Marks left by shoes are particularly visible near floor level on the platforms. Due to the particular characteristics of the walls (stonework), it is not possible to remove marks with high-pressure cleaning equipment. Various protective coatings have also proven to be inadequate. In order to reduce the number of unsightly marks and in consultation with the Austrian National Heritage Agency, Wiener Linien installed stone tiles on the pedestal area of the platforms at Alser Straße station, with the aim being to reduce the marks on the walls near floor level. These tiles are also easier to clean than stonework. The second platform was re-opened at the end of August. The work still remaining, such as the renovation of the facades, will be ongoing until the end of autumn 2015, but will no longer cause any inconvenience to passengers. All of the work will be completed by the end of the year, several months earlier than originally planned.

Further historical stations scheduled for renovation

The next major project as part of the U6 revitalisation programme is scheduled to start at the beginning of 2016, when the preparation work for the complete renovation of the Währinger Straße U6 station, which was also designed by Otto Wagner, will start. This project will be similar to that at Alser Straße, i.e. also involving the alternate closure of platforms without interrupting operations. The aim is to also completely renovate the Nußdorfer Straße station and to renew the facade of the Gumpendorfer Straße station by 2020.

The revitalisation of the U6 line, however, also involves renovation projects other than those relating to the historical stations of the former urban railway. The Thaliastraße station has also been undergoing renovation work during normal operations since 2014. Among other work, this station, which is around 35 years old, received a new roof and new platforms in autumn 2015. Besides the glass facade being renovated, accessibility and the lighting at this station have also been improved. The platforms were renewed at the Michelbeuern station in summer 2015 and a tactile guidance system for the visually impaired installed. The intention is to establish a new underground intersection here in a few years where the U6 and the new U5 lines will cross. As such, the past, the present and the future will all intersect here, with the U5 being the first underground line on the Vienna underground network to operate completely automatically.

Biography

After graduating at a technical college, Günter Steinbauer studied engineering at the Vienna University of Technology before joining Wiener Linien in 1982. After starting in the Infrastructure Maintenance Department, he went on to serve in numerous positions in which he facilitated the expansion of the Vienna underground network, such as the Project Leader for the extension of the U6 to Siebenhirten and as the Head of New Construction Projects. Since 2001, he has been one of the General Managers of Wiener Linien and CEO since 2004. In this position he is also responsible for vehicle technology and infrastructure. Over the course of his career at Wiener Linien, Günter has reorganised building and vehicle maintenance, been responsible for the renewal of the vehicle fleet and introduced electrically powered buses to Vienna. The further expansion of the public transport network remains one of his main focuses. His many years of experience as a member of numerous industry and lobbying groups is particularly valuable here.