Cogwheel steamlocomotive HG 3/4 # 1 of the Dampfbahn Furka Bergstrecke left the Furka summit tunnel with the "Blue train" 134 from Oberwald to Realp, and entered Furka DFB station on 2160 meter a.s.l. In the rear of the train is pusher diesel tractor Tm # 506, which was helper through the 1874 meter long Furka summit tunnel (opened in 1926) where there is no cogwheel. The grade in the tunnel is around 3.0 %, sometimes it is slippery and the BAV (Federal office of transport) requires this pusher service in direction from Muttbach-Belvedere in the Valais to Furka DFB in Uri, because to safety reasons. The Tm # 506 with a 125 horsepower Saurer diesel motor was built by Asper in 1953 and came to the DFB from the CJ (Chemins de fer du Jura) in 1994. The vehicle is used for work in the summit tunnel and to serve the restaurant in Furka DFB (there is no road here, but one to Muttbach-Belvedere), too.