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Kaiserslautern: Spring start for construction?

Reinhold Kasch explains how a medium-sized German city has gone about reviving a long-dormant tramway.

Kaiserslautern is a city of 100 000 people in south west Germany, halfway between Mannheim and Saarbrücken. It is the capital of Western Palatinate, a hilly, rather agricultural region. Due to its location in the French-German borderland, Kaiserslautern gained importance as a garrison town, shaped by the various conflicts between the two neighbour countries.

During the 19th century, industrialisation spawned tools and - machinery manufacturers, and the city is still famous for its Pfaff sewing-machines. The regional economy has experienced a severe recent decline, due to closure of several industrial enterprises and downsizing of military bases. The University of Kaiserslautern and the Kaiserslautern Polytechnical Institute are increasingly taking to the role of 'job-machines', both triggering the re-development of the local economy to post-industrial standards.

The first Kaiserslautern tramway was inaugurated on 18 December 1916. It had a maximum line length of just about 10 km and mainly consisted of an East-West cross-city trunk line. In the early 1930s, the tram was gradually replaced by buses, and finally closed on 1 July 1935. The only trolleybus line in Kaiserslautern became operational on 29 October 1949, was extended several times, and finally reached a maximum line length of 11.1 km, partly following the former tramway alignment.

Lack of investment and high refurbishment costs forced the trolleybus line to close, after much public discussion, on 30 November 1985. Since then the public transport passenger in Kaiserslautern has relied on local and regional buses. The railways cannot respond sufficiently to the demand for local public transport.

Kaiserslautern once was a hub of the Palatinate railway network, built for economic as well as military reasons. Today, only the major lines remain, branch lines have closed in the 1950s and several trunk routes curtailed to feeder lines, offering only a limited range of services. The swing back in favour of railborne transport came with the process of European deregulation and regionalisation of public transport (since around 1990), handing over the responsibility for regional and local public transport to the political bodies of the Federal States and the districts.

In due course, the State of Rhineland-Palatinate took to a moderate pro-rail policy, materialising in the state-wide integrated timetable for rail and bus services, enhanced through-ticketing and reopening several branch lines. New, as well as established rail services, are increasingly subject to tendering, and some lines were already won by private, i.e. nonfederal rail enterprises.

Presently, Intercity services link Kaiserslautern to the cities of Saarbrücken and Mannheim. Regional rail services provide connections to several regional sub-centres, such as Bingen, Pirmasens and Lauterecken. The central railway station is located in the southern part of town, about 1.5 km from the city centre. Regional passengers bound for the city centre therefore have to change to local buses or walk. Two other stations (Kaiserslautern Pfaffwerk and Kaiserslautern West), served by local trains only, are to the west of the city. A restricted catchment area and low patronage keep their importance for public transport rather limited.

Starting point

Towns and villages around Kaiserslautern are socially and economically closely intertwined with the city itself. Daily, around 15 000 people from the North-West commute in, for shopping, work, leisure and education. Most destinations are in the inner city, not directly accessible for the railway passenger. Regional buses, on the other hand, terminate at the central bus station, west of the city centre and a 2 km walk from the central railway station. The commuters demand for regional passenger services penetrating the city centre becomes therefore evident.

Case of the Bachbahn

Among the lines closed down in the car-minded past, was the line from Reichenbach to Weilerbach and Otterbach, aptly named Bachbahn ('Brook line'), connecting at Otterbach with the Lautertalbach trunk line from Lauterecken to Kaiserslautern. On 25 May 1972, passenger traffic ended on the Bachbahn. The Weilerbach-Reichenbach section closed to all traffic in 1989, and on 31 December 1994 the final section, Otterbach to Weilerbach, lost its goods traffic. In 1996 the Federal Railway Board agreed to shut down this last part of the Bachbahn as well.


The first ideas to reinstate Bachbahn passenger services as light rail materialised in 1995. Several feasibility studies were carried out, and the Kaiserslautern town planning department took advantage of the opportunities the project bears for urban revitalisation and regional integration. On 25 October 1999, the city council finally opted in favour of the LRT project. Why did they choose light rail and not, for instance, an improved bus scheme?

Choosing the mode

Compared with buses, railborne rapid transit has several well-known advantages in everyday operation. Due to their generally grade-separated or independent alignment, they are more reliable and provide higher commercial speed than streetborne services. Vehicle capacity is generally higher than with buses and multiple-unit operation allows easy adjustment of capacity to match passenger demand. Safety is generally higher, and energy consumption and emissions lower.

Apart from this, rail services are, due to their alignment and trackwork, easily recognisable, even if vehicles are not present, even to a customer not familiar with the public transport system. A bus route lacks this psychological momentum. Also, rail vehicles themselves are more likely to serve as sources of public identification and pride, as can been seen in Zürich for example. The public awareness towards railborne, versus streetborne modes of public transport, featured high in the considerations of the political proponents at Kaiserslautern.

To avoid the one great knock-out criterion to light rail (high investment in infrastructure) it was decided to propose a low-cost, economised system, using railway infrastructure already in situ, and stick to components off the shelf, instead of applying tailor-made, sophisticated solutions. Initial cost-benefit analyses and careful operational examinations led to the conclusion that the economics of a LRT system at Kaiserslautern are sound and that the economic and social benefits outweigh negative implications, even on a short-term basis.

The Kaiserslautern model

As has become rather fashionable, Kaiserslautern, too, will follow the world famous Karlsruhe approach: Re-using sections of closed regional railways and linking them to newly-constructed inner-city trunk lines to form a radial light rail network with the city centre as its core. This configuration allows direct rail access from the suburbs and regional sub-centres to the city centre.

Photo by Reinhold Kasch
A Saarbrücken LRV on the tramway section near Hauptbahnhof (Main Station).
A diesel-electric version of this vehicle is proposed to serve Kaiserslautem.

Referring to the legal framework of public transport, such a light rail system has to be operated under heavy rail operational regulations and safety requirements (Eisenbahnbau-undbetriebsordnung EBO) when running on railway alignment. It would be considered as light rail when running in town, thus applying light rail operational regulations (Bau- und Betriebsordnung fur Straßenbahnen BöStrab). In legal terms, any system comprising railway and light rail elements or operational characteristics will figure as a 'dual-mode system', irrespective of energy supply.

What makes the Kaiserslautern project so unique among all current LRT proposals is precisely the mode of energy supply chosen for the vehicles. As neither the Bachbahn nor the Lautertalbahn are electrified, the LRVs will be propelled by internal combustion engines. Electrification of the Bachbahn was not considered suitable, due to high investment costs, not met by corresponding savings in operation. This feature makes a major difference to the Karlsruhe or Saarbrücken 'dual-mode' light rail vehicles, which are electrically driven, albeit with ac/dc traction current supply.

The Bachbahn vehicles would be derived from existing medium or low-floor light rail vehicle designs, for example the Bombardier-built Saarbrücken dual-voltage LRV. Inner-city tramstops and railway platforms, therefore would require only moderate design changes and would be rather unobtrusive. The vehicles would be equipped with reliable diesel-mechanical or diesel-electric drives derived from railway or bus mass production, thus allowing low construction and maintenance costs. An already operational diesel tramway, albeit with vehicles built to rail- way design standards, serves the short inner-city section of the Vogtlandbahn at Zwickau, opened in October 1999 (as reported in Tramways & Urban Transit, February 2000, pp52-55).

The Kaiserslautern proposal, therefore, adds a new variation to the broad scope of light rail transit: The diesel-powered railway-tramway.

Financing light rail

The Bachbahn scheme will be realised as a PPP turnkey project with two separate bidding processes comprising the Design-Build-Transfer stage and the Operate stage, respectively. As responsibility for railborne regional transport lies with the Federal State of Rhineland-Palatinate and its regional subsidiary, Zweckverband Schienenpersonennahverkehr Rheinland-Pfalz Süd (Railway Passenger Transport Authority for Southern Rhineland-Palatinate), building and operating the line will be commissioned by these two political bodies. Local authorities will not be involved in financing the project.

Designing and build phases will be carried out by a private-sector investor, with local authorities only setting the general terms. The investor will have to meet the initial investment sum of net 12 million Euros, covering infrastructure and vehicle investments. This sum might in part be counterbalanced by Government grants, in accordance with European legislation. However, due to recent budget restraints, a definite decision on the amount of this sum has not yet been made.

After completion, the line will be handed over to the Railway Passenger Transport Authority, which then will franchise operations to a private operator. The revenue will pay for the investment rates of infrastructure and vehicles.

This financial approach stands in marked contrast to conventional implementation of LRT schemes. Private pre-financing, turnkey building and franchised operation offer considerable advantages to the proposing political bodies insofar as the financial risk is reduced to a minimum - and transferred to the private sector as well! If everything works well, building will start in spring 2001, with the first section of line operational in 2004.

Project stages

The Bachbahn project will form the first stage of a regional light rail network, based on a new trunk line penetrating the city centre of Kaiserslautern, and on several railway lines converted from heavy rail to light rail operation. Stage 1 will comprise refurbishment of the Bachbahn from Weilerbahn to Otterbach, the use of the existing DB railway line from Otterbach to Kaiserslautern West and the new tramway section from Kaiserslautern West to Kaiserslautern Town Hall. The tramway section onwards to Kaiserslautern Central Station will form stage 2.

Operation concept

The initial headway for the Bachbahn light rail line will be 60 minutes, reduced to 30 in the peak. This service will require two train sets. Regional heavy rail services on the existing Lauterbahn will be connected with the Bachbahn at Otterbach, offering attractive services from Lauterecken to the centre of Kaiserslautern.

Currently, an option is being considered to integrate Lauterecken services with the Bachbahn and run them with LRVs, as well. In this case, a further two train sets will be required. The resulting two-line network would materialise, if project stages 1 and 2 become operational simultaneously. A first step towards upgrading the Lauterecken service was the re-introduction of weekend services with a 30-minute headway from mid-April 2000, serving the Rhineland-Palatinate Gardening Show.

Integration and patronage

The Bachbahn light rail service will be part of an integrated regional public transport system. Through-ticketing to local and regional bus services is envisaged, probably under the auspices of the regional joint tariff association, Westpfalz Verkehrsverbund. Regional bus services will be suitably re-routed in accordance with the Bachbahn services, serving as feeders or complementary lines. At the central station Rathaus/City Bahnhof, 13 local bus lines will allow easy interchange with the Bachbahn; at the central railway station interchange to all railway services and a further three bus lines is possible.

Passenger flow increases are estimated at 25% for the Bachbahn area and 60% for the Lautertalbahn rail service, equalling daily passengers 1000 and 600 respectively. Considering that on other regional rail lines recently converted to LRT operation, passenger figures doubled (Schönbuchbahn near Stuttgart) or quadrupled (Rurtalbahn Düren-Jülich or Saarbrücken Light Rail) within two years after inauguration, these assumptions seem rather moderate, but provide for an economically sound cost-benefit analysis.

Alignment and track

Photo by Reinhold Kasch
The Saarbrücken LRV at Kleinblittersheim station on the railway section. Except for the overhead wire, this might well be Weilerbach terminus of the Bachbahn in a few years time.

From Weilerbach to Otterbach, the former Bachbahn single-track alignment will be refurbished to heavy rail standards. From Otterbach to Kaiserslautern West, the existing Lautertalbahn single-track line will be retained and shared with regional goods and passenger services. The new inner-city tramway section (stage 1) will start at Kaiserslautern West and continue for 1.6 km to the initial terminus at Kaiserslautern Town Hall. This section will be routed via existing streets which will retain car traffic, but dedicated in certain sections as traffic calmed streets. The city section is designed as double track alignment on street and at grade, and will be built to tramway standards. Three intermediate stops are proposed at Kaiserslautern Westbahnhof, Kammgarn and Fachhochschule (Polytechnical Institute).


Photo by Reinhold Kasch
The central bus interchange at Kaiserslautern Fruchthalle would be replaced by a combined tram/bus station City/Rathaus a little further west.

The initial city centre terminus, Kaiserslautern Rathaus/City Bahnhof, will be integrated in a major city centre revitalisation scheme and form part of the central light rail - bus interchange station. Urban revitalisation will be undertaken also around the two other tramstops to redevelop former industrial premises. By now, they are connected already with the Kaiserberg area to form the site of the Palatinate Gardening Show 2000.

From Kaiserslautern Rathaus the line will continue on street via the historic city centre (tramstop Marktstrasse) and the duly named Eisenbahnstrasse (railway street, tramstops Mozartstraße and Parkstraße) on to a stub terminus adjacent to the central railway station (tramstop Hauptbahnhof). This section will form stage 2. Today, the Eisenbahnstraße is already a major public transport trunk route, with several heavily patronised bus lines between Rathaus and Hauptbahnhof.

A connecting track to the DB rails will be built later, as well as a tram section from Rathaus to Nordbahnhof (and on to Winnweiler via DB tracks) and from Hauptbahnhof to Universität, using existing DB tracks and a short stretch of new tram alignment.

The next steps

Initially it was anticipated that the short stretch, from Kaiserslautern West to Rathaus (stage 1) alone would generate sufficient passenger traffic to justify its operation. A closer look at current passenger flows revealed a much greater operational benefit could be achieved by converting the Lauterecken railway and Bachbahn light rail operation and having both lines run through to Kaiserslautern Central Station as an initial service. A detailed cost-benefit analysis is under way, which jointly covers project stages 1 and 2. In due course, the bidding process will be initiated, with infrastructure construction and urban redevelopment lasting from 2002-04. If everything functions according to plan, the system may be operational by then.

Kaiserslautern's LRT proposals are innovative, not so much because of the underlying idea (is there any medium-sized town today which does not propose a dual-mode LRT scheme?), but because of the way the idea is taken towards materialisation. It is this unpretentious how-much-can-I-get-for-mymoney attitude that increases the chance of realisation considerably and that might serve as a model to similar schemes. The author thanks Christian Ruhland of the Kaiserslautern town planning department and Dr. Jürgen Wolf of Dr. Wolf-Verkehrsplanung, Darmstadt, for their assistance in preparing this article.


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