ICN tilting train RABDe 500 # 031 is running through the Wattinger curve on the Gotthard mountain line near Wassen. Not visible in the rear and in the Wattinger loop tunnel is the diesel tilting train VT 612 # 901/902 of the Deutsche Bahn Systemtechnik Minden, which is used for homologation of the line to the higher velocity of the tilt trains. Since there are no tilting trains running over the Gotthard mountain line any more, the train is only on a tranfer run. In the past, such test runs took place periodically to check the conditions (track position, etc.) for the increased speeds of the N series of trains (tilting train). The ICN has the clutch cover open, the clutch extended and an auxiliary clutch mounted on it so that it can be quickly coupled again with the diesel railcar VT 612 in the opposite direction of travel.