Following the energy crisis in the 1970s, the political climate changed, and in 1977 the city council decided to not close the tramway anyway.

In 1979, Oslo Sporveier ordered ten vehicles from Duewag, with planned delivery in 1982.

In addition, fifteen units would be license-built by Strømmens Verksted, with delivery the following year.

All the motors were built by the Norwegian company Norsk Elektrisk & Brown Boveri (NEBB).

Oslo was the third tramway in the world to take into use thyristor controlled motors on the main part of their fleet of trams, after the systems in Helsinki, Finland, and Hanover, Germany.

There were few problems in the start, although the pantographs had technical problems and there were occasional power failures in the overhead wires due to out-of-date rectifiers not being able to handle the increased power usage.

[5] Due to a labor dispute about privatizing the operation of the tramway and the Oslo Metro, the ownership of all trams and metro trains, including the SL95, were transferred to the municipally owned limited company Oslo Vognselskap in 2007.

[6] Suggestions have been made to extend the trams with another center section, adding another axle and articulation, but these plans have been rejected by the company.

[7][8] Sporveien and the Oslo City Council have decided in 2018 to purchase 87 tramcars from CAF designated SL18, which will replace both the SL79 and the SL95 units.

Following the delivery of the SL95 low-floor trams in 1999 and 2000, Oslo Sporveier has a pure articulated fleet.

The newer series has a greater turning radius, heavier axle load and is two-directional.

The radius and axle load of the SL95 makes it impossible for it to operate around Majorstuen, requiring lines 11, 12 and 19 to use SL79-units.

[11][12] The SL79 operate on the Briskeby, Ekeberg, Frogner, Gamleby, Grünerløkka–Torshov, Kjelsås and Vika Lines.

Each service has a ten-minute headway, giving a five-minute interval on section that are served by two lines.

[13] The SL79 is an articulated tram built exclusively for the Oslo Tramway in two series with different specifications.

Each of the two NEBB 4ELO 2054 B thyristor monomotors have a power output of 217 kilowatts (291 hp), giving the vehicle a power output of 434 kilowatts (582 hp) at 750 V. Maximum speed is 80 km/h (50 mph).

The first series was delivered with a deeper blue color than has been tradition with Oslo Sporveier trams, but all have since been repainted to match the standard livery.

Prior to the delivery of the second series, a single tram was painted deep red to match the buses and the T1000 trains used on the Oslo Metro.