The Tm 506 is used in the area of the Furka summit tunnel, i.e. between the two stations Furka and Muttbach. This vehicle is used for pushing services, to supply the mountain restaurant at Furka station from Muttbach and to carry out construction work in the tunnel. The Tm 506 was taken over by the Chemins de fer du Jura (CJ) in 1994. After some damage had been repaired, it was put into service in the summer of 1996 during the renovation of the Furka crest tunnel. At the beginning of 1997, the Tm was hired by the Vanoli company for use in the Lower Engadine, after which it did service for a catenary company on the Albula line of the Rhaetian Railway. In the summer of 1999, the vehicle returned to the DFB. After modifications to the electrics and the braking system in the winter of 1999/2000, the Tm 506 is used in the area of the Furka-Muttbach stations for work in the crest tunnel and for pushing service.