The G 3/4 is a series of light steam locomotives that were first delivered to the Landquart-Davos Railway (LD), which later became the Rhaetian Railway. The latter then ordered further locomotives of this type. The 16-vehicle series with the 1'C (2-6-0 T) axle arrangement is divided into five series, some of which differ slightly in terms of dimensions. # 11 was built in 1902 by the SLM. In 1977, # 11 went to the Eiger Model Railroad Friends in Zweilütschinen, who used it in museum operations on the Bernese Oberland Railway and the Brünig Railway. Locomotive # 11 returned from the Bernese Oberland to Graubünden in 1999 after having been out of service since 1990 due to boiler damage. The engine has borne the initially unofficial name Heidi since it appeared in a feature film of the same name in 1952. In 2014, it was overhauled by the 1889 Club and the DLM steam locomotive and machine factory. It was given a new welded boiler with superheater. Thanks to the new light oil firing system, sparks are avoided so that it can also be used when there is a risk of forest fires.