The Combino is a low floor tram produced by Siemens Transportation Systems (formerly Düwag). The first prototype was produced in 1996 at the Duewag works in Düsseldorf, however the trams are currently made in Krefeld-Uerdingen . Because of its modular design , the Combino was one of the most successful tram types for a while.

Use of the Combino world-wide

Around 500 trams went into service in the following cities:

• Germany
  • Augsburg
  • Düsseldorf (NF10 )
  • Erfurt
  • Freiburg
  • Nordhausen
  • Potsdam
  • Ulm
• Rest of Europe
  • Amsterdam
  • Basel
  • Bern
  • Poznań
  • Verona
• Rest of the World
  • Hiroshima
  • Melbourne (D1/D2 class)

Technical specifications

The tram is largely made out of aluminium, with a welded underframe to which the body framework is bolted in sections, which means that the Combino can easily be adopted to different lengths, widths and gauges. The length of the cars varies from 19 m (Nordhausen) to 43 m (Basel), accommodating between 100 and 250 passengers. All versions are designed to have a 300-mm floor height and a 10-tonne axle load. It can be built as a one-way or a two-way vehicle , and it is also produced as DuoCombino with an additional Diesel propulsion system.

2004 - Callback due to flaws in construction

On March 12, 2004, Siemens admitted to problems concerning the stability of the car bodies and, as a measure of precaution, instructed all public transportation services to take all Combinos with a mileage of more than 120,000 km out of service. Subsequently, hairline cracks were found in the joints of the aluminium bodies, which could cause the roof to collapse in case of an accident. On April 12, Siemens admitted that the Combinos had been built according to the specification of a wrong technical norm . As of May 18, 2004 a large number of cars were still out of service, because they had not yet been refitted. Siemens put provisions of more than € 300 million into its balance sheet, but some analysts still expect a higher fallout.

Potsdam

In 1997, the public transportation authorities of the city of Potsdam were the first to purchase Combino cars world-wide. The advantages of its low-floor technology were stressed during the introduction. Until 2009, a total of 48 cars was to be bought.

The order from Potsdam was of great importance for advertising the Combino in other cities. Cars from Potsdam were frequently used for presentation.

After a short period of service, many inhabitants of Potsdam noticed noises during the operation of the cars louder than those of the previously used Tatra cars. In March 2004, the sixteen Potsdam cars were taken out of service. As a replacement, several Tatra cars which had been given to museums were taken back into service. The shortage was aggrevated by the fact that several old cars had been sold to Ukraine just a month before.

In June 2004, Potsdam and Siemens "amicably" declared that the 32 outstanding cars were not going to be delivered. This decision is likely to have consequences for other cities.

Amsterdam

In June 2004, the first Amsterdam Combinos passed the mileage threshold of 120,000 km. Those trams were taken out of service. Earlier already, Siemens technicians had identified hair cracks in the door segments of two of Amsterdam oldest cars. But, according to Siemens, those turned out not to be dangerous, which is why the cars continued to be used. In the end of April, it was decided not to call upon the twelve cars which were still outstanding at that time.

Siemens is currently experimenting with a new model in Amsterdam, the Combino 2091. In September, it turned out that 32 of the 48 oldest Combinos had cracks in the floor segments. Siemens is expected to patch up these trams temporarily. A structural solution for the construction flaw has been announced for September 2004. Beginning in 2005, a two-year program will be started to fix the cars. All Amsterdam cars are to be brought to the plant in Germany where their hulls are to be strengthened.

See also

• Ultra low floor