The electrification of the ECML necessitated the procurement of new high speed electric traction. The options and requirements for this trainset were hotly deliberated for a number of years. On 7 June 1978, the electric-powered prototype Advanced Passenger Train (APT) was unveiled; it was at one point intended for the APT to be the next major intercity express train. However, due to various factors including technical issues, the APT programme was curtailed during the summer of 1989. Shortly thereafter, two alternative options were explored, an electrified version of the InterCity 125 (known as the "HST-E"), and the mixed-traffic locomotive; these were both intended to a peak service speed of 125 mph.