The new Stadler built cogwheel diesellocomotive HGm 2/2 # 702 of the Matterhorn-Gotthard Bahn (MGB) is pulling the SERSA track measuring train from Disentis via Oberalp pass-Andermatt-Oberwald to Brig, over the 120 meter long and 24 meter high Bugnei viaduct, which was built between 1913 and 1926, with interruptions. Behind the measuring car P # 10175 is the flat car X 4932S with crane of the Matterhorn-Gotthard-Bahn, which serves as brake van, especially in the cogwheel sections.