 In the early 1950s it was refurbished, replacing the original wooden cable cars with metal bodied cars in a red colour scheme.A further refurbishment in the late 1970s resulted in an extension at the upper end of the line, and the introduction of the current cars, in blue and white.The line is operated by the Verkehrsbetriebe Zürich (VBZ), the municipal transport operator for the city of Zürich, and carries around 600 000 passengers per year.