SL79 is a class of 40 articulated trams operated by the Oslo Tramway of Norway. The trams were a variation of the Duewag trams that had been developed by the German manufacturer since the 1950s. The six-axle vehicles are unidirectional with four doors on the right side. The trams can seat 77 passengers three and four abreast, with an additional 91 people able to stand. Power output is 434 kilowatts (582 hp), provided by two motors on the two end bogies, that supplement a central unpowered Jacobs bogie located under the articulation. The trams are 23.0 metres (75.5 ft) long and 2.5 metres wide. They are capable of 80 kilometres per hour (50 mph) and have standard gauge.

Düwag or Duewag, formerly Waggonfabrik Uerdingen, was a German manufacturer of rail vehicles. It was sold in 1999 to Siemens with the brand later retired.