The city of Berlin has ordered new trams, called Urbanliner.

Now it has been reported in the press that their commissioning has been repeatedly postponed, probably because they may be too heavy for Berlin’s bridges. It is not entirely clear how many bridges are involved, but it is said to be at least one bridge.

Fact is, at around 100 tons, the Urbanliner is about twice as heavy as previous models.

If it is true that the weight of trams has doubled within one or few generations, then this does not reflect well on the manufacturer. It seems that the weight was completely ignored.

However, bridges are only one aspect affected by vehicles that are too heavy. Increased energy consumption is also associated with this. Furthermore, I would be surprised if the track bed did not also suffer from the high mass and be subject to increased wear and tear. It is questionable whether this could in turn compromise safety and require additional tests. I consider it possible that there could be a risk of the track bed tipping over and the vehicle possibly derailing or even overturning; this would then needed to be examined.

Incomprehensible for me how the most important physical parameter can be ignored in such a way and what consequences has to be dealt with then…

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