Sparkling clean on its journey: the Sihltal Zürich Uetliberg Bahn

It is a city, commuter and sightseeing railway all in one: The Sihltal Zürich Uetliberg Bahn, or SZU for short, combines hectic urban life with the beauty of nature. In addition to punctuality, cleanliness is also a high priority for the small but mighty public transport company.

Departure from Zurich main station – arrival in the countryside

The Sihltalbahn, the S4, transports work commuters and sightseers between the city of Zurich and the Sihltal agglomerations of Adliswil and Langnau am Albis. Recreation-seekers and animal lovers use this line to visit the Langenberg Zoo – the oldest zoo in Europe – or to experience untouched nature up close in the Zurich Wilderness Park Sihlwald.

The Uetlibergbahn, the S10, takes day-trippers from Zurich main station up to Zurich’s local mountain, or rather to the Uetliberg terminus, 813 m above sea level. With a gradient of 79%, the Uetlibergbahn was for a long time the steepest standard-gauge adhesion railway in Europe.

No stops on the way to the future of mobility

In recent decades, SZU has permanently adapted to its passengers’ mobility needs. Since the two lines were connected to Zürich Hauptbahnhof, Zurich’s main railway station, in 1990, the number of passengers transported annually has risen from 4 to 15 million. The company even expects 20 million by 2030. SZU is handling with these services within its long-term strategy to increase capacity, including the procurement of state-of-the-art rolling stock and the further expansion of the infrastructure.

Bachofen's wide range of products largely covers the needs for the washing system ...

Retrofit for the outdated washing facility

An important renewal project last year was the upgrade and automation of the ageing washing facility for cleaning the exterior of the trains. The project aimed to increase cleaning efficiency, improve safety and reduce personnel and costs by half. SZU ordered almost all the components and automation systems necessary from Bachofen. Project manager Luke Zollinger comments: «Bachofen’s wide range of products largely covered our needs. In addition, procurement from a single source offered us a guarantee that the parts would work together perfectly. »

... and ensures perfect interaction.
Luke Zollinger, Fleet Manager Rolling Stock

Comfortable travel on board with Bachofen

The shopping list with which SZU approached Bachofen was varied and long. The cross-divisional requirements ranged from safety components of all kinds, valve technology and pressure sensors, pneumatic systems and signal columns to radar sensors, proximity switches, level probes, silencers and operating elements. Luke Zollinger: «The technically experienced specialists from Bachofen provided us with expert and professional support in evaluating the parts. The deliveries were made punctually and reliably – qualities that we have also taken to heart. Bachofen delivered exactly what we needed in a timely manner. Nothing was imposed on us. »

In addition to punctuality, the cleanliness of trains is also a high priority in public transport, as it is an important image factor. The fact that the SZU’s vehicle fleet makes a sparkling appearance in its immaculately shining red is due not least to the perfect cooperation between the SZU and Bachofen.

«It is really cool to work alongside Bachofen. It convinced us with its understanding of our concerns, the technical know-how of the consultants and the range of products. For the retrofit of our washing facility, the principle of ‘everything from a single source’ has proved its worth. »

Luke Zollinger, Fleet Manager Rolling Stock

Sihltal Zürich Uetliberg Bahn SZU AG

The Sihltal Zürich Uetliberg Bahn SZU AG was formed in 1973 from a merger of the Sihltalbahn, founded in 1892, and the Zürich-Uetliberg railway company, which had existed since 1922. The latter in turn had emerged from the Uetlibergbahn-Gesellschaft founded in 1875. SZU has been part of the Zurich Transport Network (ZVV) since 1990 and has been operating the Zimmerberg bus – as the transport company responsible for the Zimmerberg market area – since 1995. SZU operates the S4 line between Zürich Hauptbahnhof and Sihlwald as well as the S10 line from Zürich Hauptbahnhof to the Uetliberg. The company also operates the aerial tramway between Adliswil and Felsenegg.

Foundation of SZU AG

Zurich, Giesshübel

Number of employees
approx. 180

Mischa Nugent

Bachofen customer since the early


Technology partner