NSB Class 73 is a class of 22 electric multiple units built by Adtranz for the Norwegian State Railways. The four-car trains were modifications of Class 71, which was again based on the Swedish X2. The A-series consists of 16 intercity trains; they were delivered in 1999 and 2000 and are used on the Bergen, Dovre and Sørland Lines. The intercity service was branded as Signatur until 2003. The B-series consists of six regional trains delivered in 2002 and used on the Østfold Line. The regional trains were originally part of the Agenda concept. The trains have a power output of and a maximum speed of . They have an overall length of and have a capacity for 208 seated passengers in the A-series and 250 in the B-series. The trains have tilting mechanism allowing for faster travel through curves.