|Years of manufacture||1968 to 1990|
|Power||Direct current, Alternating current (only built as demonstrators)|
The Siemens–Düwag U2 is a six-axle, bi-directional, articulated light rail vehicle. They may be coupled together to form longer trains. The cars were constructed by consortium of Siemens, Wegmann & Co. and Düwag in West Germany.
The U2 was originally designed for Frankfurt's light rail transit system. Based on prototypes known as the U1, a total of 97 U2 cars were built for Frankfurt beginning in 1968. Düwag later successfully bid their U2 design for the city of Edmonton's new light rail system. Edmonton took delivery of their first 14 vehicles in 1977, eventually purchasing a total of 37 vehicles. Further orders for the U2 were placed by the cities of Calgary and San Diego.
From 2010 to 2012, an agency in Argentina acquired 11 U2 cars secondhand from San Diego. They are used to operate a new light rail system between the cities of Mendoza and Maipú.
- San Diego Metropolitan Transit System (MTS) - San Diego, CA
- De Leuw, C. &. C. (1976). Light rail transit : State of the art review. United States: