In 1891, the Landquart Davos Railway received two Mallet tank locomotives from Maffei of Munich for a price of 68,400 Francs each. They had four driving axles in two groups, no leading or trailing axles and were numbered 6 and 7. Their official designation was G 2x2/2. When the LD became the RhB in 1895, they were renumbered 21 and 22. In 1910 and 1911, they were rebuilt with a leading axle where they also got larger water tanks and smaller coal bunkers.

After the RhB had electrified its network, they were sold to Brazil in 1920 to the Companhia de Mineração Santa Matilde. There they were sold again to the Rede Sul Mineira de Viação, which rebuilt them to tender locomotives in 1937 and 1938. Nevertheless they were withdrawn after a short time and scrapped by 1944 at the latest.