 During the 1930 Oslo Sporveier decided they needed more rolling stock, and cooperated with Strømmens Værksted to create the Goldfish-series.Forty-six units were delivered in 1937–40, with twenty-four delivered in the street version, series E and twenty-two in the suburban version, series B.Built with an aluminum chassis, they were quick and light, with a distinct streamline shape, making them look like a goldfish.