THEARRIVAL of the five-section Cobra low-floor LRVs, which are 36m long, and the extension of 23 Tram 2000 cars to 28 m with the addition of a low-floor centre section, posed a problem for Zürich tram operator VBZ.

The overhaul bays at the main workshop are laid out on either side of a central traverser, which is only 21 m wide. Rather than demolishing the 25-year-old building, VBZ came up with an innovative traverser design. As well as two straight tracks, which enable vehicles to cross from one side of the pit to the other, the square platform has four curved tracks which turn through 90í on a 16 m radius. These are able to accommodate vehicles up to 36·5 m in length.

Built by Inauen-Schätti AG, the 105 tonne steel platform is 215 mm deep, and is carried on 80 rollers. Powered by four 22 kW motors, it can handle trams weighing up to 45 tonnes.