 From then onwards, the network's operator was "Städtische Strassenbahn Biel" / "Tramway de Bienne" (TrB).After the 1901 takeover of the horsecar line by the city of Biel/Bienne, work began promptly on its electrification, and conversion to metre gauge.Twelve electric motor tramcars were procured, and individual horse car trams were regauged for use as trailer cars.