Based on the Eurosprinter concept the ES 64 U was developed as a universal electric locomotive with a top speed of . The series ES 64 U is only capable of operating on the 15 kV 16.7 Hz AC supply. It is in service in Austria with ÖBB as Class 1016. Unlike the F series, all U series are equipped with quill drive instead, thus reducing the track forces. The ÖBB assigned the protected name Taurus to Class 1016 (and later to the Classes 1116 and 1216); since then all ES 64 U+ series are widely known as 'Taurus' locos.