The Siemens–Duewag U2 was built by Siemens, in association with Duewag and Wegmann & Co built between 1968 and 1990. The car was based on the original U1 tram built in 1965 for the Frankfurt U-Bahn. The U2 was also designed for and used by the Frankfurt U-Bahn. It was later exported to America for use on light rail systems in Edmonton, Calgary, and San Diego.