Stadtbahn


A Stadtbahn is a type of rail transport. One type of transport originated in the 19th century, firstly in Berlin and followed by Vienna, where rail routes were created that could be used independently from other traffic.
Again in the 1960s and 1970s Stadtbahn networks were created but now by upgrading tramways or light railways. This process includes adding segments built to rapid transit standards –usually as part of a process of conversion to a metro railway– mainly by the building of metro-grade tunnels in the central city area. In the first years after the opening of the tunnel sections, often regular trams vehicles were used. These trams were followed by specially designed vehicles like the Stadtbahn B series. By the 1980s virtually all cities had abandoned the long-term goal of establishing a full-scale metro system due to the excessive costs associated with converting the tramways. Most Stadtbahn systems are now a mixture of tramway-like operations in suburban and peripheral areas and a more metro-like mode of operation in city centres, with underground stations. This 20th century Stadtbahn concept eventually spread from Germany to other European countries, where it became known as pre-metro.

History

1920s: Berlin and Vienna cross-city lines

The term Stadtbahn first arose in the first half of the 20th century as a name for the cross-city lines in Berlin and Vienna. The Berlin Stadtbahn line is an elevated heavy rail line linking the East and the West. Long distance, regional, suburban, and urban services are operated on it.
The Wiener Stadtbahn was in the beginning a system of heavy rail lines circling the city, free of level crossings, operated by steam trains. After World War I the Wiental, Donaukanal and Gürtel lines were converted into an electric light rail system with tram-like two-axle cars. In the 1970s to 1990s the infrastructure was updated, and the lines were partially relocated: they are now part of the Vienna U-Bahn services 'U4' and 'U6'. The Vorortelinie line remained heavy rail and is now part of the Vienna S-Bahn.

1960s: modern ''Stadtbahn''

Since the 1960s the term Stadtbahn has become identified with a second, now dominant, meaning, which is a reference to underground urban rail network that is used by conventional trams but planned at the outset to be eventually converted into a metro system.
Post-World War II transport policies in West German cities aimed for a separation of public and private transport. The conflicts that arose between increasing car usage and the existing tramway systems led to the so-called 'second level' concept for future light rail schemes. This concept focused on the grade separation, i.e., elevation and/or tunneling of tram lines.
Munich and Nuremberg decided to build pure, full-scale U-Bahn systems. Berlin and Hamburg planned expansions of their existing U-Bahn networks, while most West German cities decided to upgrade their tramway networks step by step, linking new 'second level' infrastructure to existing sections. While some cities regarded this solution as an interim step that would lead to a fully separated U-Bahn network independent of other forms of transport, others planned for a lesser degree of separation, one that would accommodate additional tram-like sections in the long run. For both the interim and the long-term based concepts, the following terms came into use: "U-Straßenbahn" or "Untergrund-Straßenbahn", "Schnellstraßenbahn" and finally Stadtbahn.
Some operators and cities decided to identify the term Stadtbahn with the eventual goal of installing an U-Bahn so that both the original U-Bahn logo and the derived U-Stadtbahn logos mark station entries and stops. The numbering scheme for Stadtbahn services was prefixed with a 'U', except in the Cologne Stadtbahn, Bielefeld Stadtbahn, and Hanover Stadtbahn.

1980s: Renaissance of the tramway

By the 1980s conventional tramways had been seen by decision-makers as overloaded systems for almost two decades. However, public attention focused on them at this time for two reasons.
The Stadtbahn cities' second level plans faced unexpected complications in the form of lengthy construction work, budgetary problems for tunnel projects, and protests against elevated sections. At the same time, the smaller cities which had not started Stadtbahn plans reassessed their options in relation to their existing tram systems.
East German cities had no 1960s-style Stadtbahn plans in place, and the fleets and the infrastructure were in need of massive investment and improvement. After the reunification of Germany in 1990, the use of the Stadtbahn term became popular in the former East Germany as well, as in Erfurt and Dresden.
Stadtbahn in this wider meaning is thus not a clearly defined concept, but a vague one linked to a set of attributes, much in the same way that "Straßenbahn" is linked to very different, sometimes mutually incompatible attributes. A system that is called Stadtbahn today may not have all of the Stadtbahn attributes: barrier-free access, higher cruising speed than tramways, doors on both sides of the train, driver's cabs on both ends, higher operating voltage, wider cars with comfortable seats, and so on.

1990s: The tram goes railway

In 1992 Karlsruhe started an innovative new service, using both heavy and light rail infrastructure, to link the wider region to the city. The vehicles were designed to comply with technical specifications for the heavy railway and for light rail. Such vehicles are called Dual-System Light Rail Vehicles. The meaning of Stadtbahn was enlarged to encompass this new type of "tram-train" service. In other regions, stimulated by the Karlsruhe example and planning to copy it, other terms are in use: Stadt-Umland-Bahn, Regional-Stadtbahn.
Straßenbahn and Stadtbahn in the Karlsruhe region are differentiated more by the nature of their city-border crossings only, and not by the technical dimension. Only those services that extend into the suburbs are called Stadtbahn. They are represented by the 'S' logo that is used for 'S-Bahn' in the rest of Germany and therefore partially conflict with it, as it has acquired a second meaning in Karlsruhe.

2000s: The Tram logo

As part of the redevelopment of their main city stations, national railway company Deutsche Bahn adopted a new logo to indicate Straßenbahn connections: a square containing the word 'Tram'. Although the design is the same nationwide, the colour varies from city to city to match local public transport operators' systems of colour-coding. The logo is part of the 'S logo scheme' initially developed by Berlin public transport operator BVG, based on the established logos for urban metro and suburban metro and including bus and ferry operations.
As the new logos became part of the information systems at more and more main railway stations, an increasing number of cities and public transport operators came to accept and adopt the scheme. As far as the Stadtbahn terminology problem is concerned, however, the scheme serves only to add further confusion to the matter, since there is no nationwide logo for Stadtbahn services. The result appears to be a contraction in the use of the term Stadtbahn, especially in cities where it has been used in its wider 1980s 'light-rail system' meaning.
In cities where Stadtbahn has the 1960s 'pre-metro' meaning, both the 'U' and the 'Tram' logo are used on city maps and on railway station signage. The 'U' Logo is normally used both where stops or stations are underground and where they serve 'second-level' pre-metro type lines. In cities which prefix all their Stadtbahn line numbers with a 'U', the 'U' logo is used at stops on services that are essentially 'classic' tram lines, not 'second-level' at all.

Regionalstadtbahn

The concept of Regionalstadtbahnen arose as a result of the harmonisation or integration of railway lines into Stadtbahn networks. In the area of Cologne–Bonn a single operational system was created by the Cologne Stadtbahn and the Bonn Stadtbahn, opened in 1974, from the conversion of two former railway lines. Further developments led to tram-train networks that rather resembled an S-Bahn. This idea was first realised in 1992 in Karlsruhe, where as part of the Karlsruhe model even so-called dual system railbuses were used, which in addition to the direct current of Straßenbahn lines could also draw power from the 15-kV-alternating current from normal DB catenary. In Karlsruhe this network reached as far as Heilbronn, away, where a Stadtbahn network was created going out from this line. Both in Karlsruhe and in Heilbronn the Stadtbahn filled both the roles of a classic tramway system as well as an S-Bahn. The Karlsruhe mixed-operation concept was also adopted by the Saarbahn in Saarbrücken. This model is today referred to in France as the tram-train.
diesel tram-train
Other Stadtbahn networks in Germany without tunnels, but which incorporate railway lines, are found in:
Although a precise legal definition of Stadtbahn was planned in the 1970s, there is currently no such definition. By law, the BOStrab regulates all Stadtbahn systems as tram systems, as long as they are light rail rather than heavy rail.

Difference between Stadtbahn and S-Bahn in Germany

While the names Stadtbahn and S-Bahn have common origin, their meaning today is different. S-Bahn is commuter rail, usually integrated into the railway network and mostly operated by the German national railway company Deutsche Bahn.
Stadtbahn, on the other hand, generally use light rail vehicles, and are usually integrated into the tram network, though the Stadtbahn portions do not operate with street running like trams do.
They also differ in legal status: S-Bahn systems are governed under the rail rules of the Eisenbahn-Bau- und Betriebsordnung, while Stadtbahn systems are tramways by law governed under the regulations of Verordnung über den Bau und Betrieb der Straßenbahnen.