The Class E 50 is an electric heavy freight locomotive built for German Federal Railways between 1957 and 1973. It belongs to the Einheits-Elektrolokomotiven (standardised electric locomotives) program and was built as heavy freight mover to be used on the increasingly electrified main lines of the DB, where they were set to replace the steam traction. In 1968 the series was redesignated as class 150 (E50).