In 1979, when second class was introduced in addition to the formerly exclusively first class "InterCity" system, this resulted in a sharp rise in popularity and demand, making the "IC" system the backbone for long distance rail travel in West Germany. By that time the technical problems had been overcome, and the top speed of was permitted on a few lines with the necessary features (LZB and adaption of overhead lines in particular). However, after having only been scheduled for pulling trains with a few first-class carriages or the odd "D"-train, the major challenge for Class 103 now was to pull heavy two-class "InterCity" trains on the long north-south stretches through West Germany. Governed by a very intense schedule, with one train per hour on every "InterCity" line in each direction, locomotives would perform well over on a single day. Given the few lines in the network where were actually reached, their effect on the wear and tear of the locos can therefore be considered a lesser factor.