AB Stockholms Spårvägar (SS) is owned by the Swedish Tramway Society (Stockholm department) as well as individual members. The company has been engaged in tramway operations on Djurgårdslinjen with heritage trams since 1991 and now accounts also for services on the City tramway with regular, modern low-floor trams. The Company’s office and depot are located in Djurgården on the waterfront, next to Liljevalchs Gallery , Aquaria Water Museum and the guest harbour, Wasahamnen .
SS was formed in 1987 by Swedish Tramway Society. Since 1991, the company is responsible for the heritage tramway operation on Djurgårdslinjen with mostly volunteer members of the Swedish Tramway Society. Since August 2010 SS is also operator for the regular service on line 7 and from Spring 2015 Lidingöbanan, line 21, on behalf of the county adminsistration (Trafikförvaltningen i Stockholms läns landsting).