TV programme looking at the development of a new Locomotive the Class 91 for the Inter City 225 train.

some information copied from wiki;

The British Rail Class 91 is a class of 140 mph (225 km/h), 6,300 hp (4,700 kW) electric locomotives ordered as a component of the East Coast Main Line modernisation and electrification programme of the late 1980s. The Class 91s were given the auxiliary name of Intercity 225 to indicate their envisaged top speed of 225 km/h (140 mph). The other end of the InterCity 225 train set is formed of a Driving Van Trailer
built with a similar body shell to the Class 91 locomotives. The
locomotive body shells are of all-steel construction. Unusually, the
motors are body mounted and drive bogie mounted gearboxes via cardan shafts. This reduces the unsprung mass
and hence track wear at high speeds. The locomotive also features an
under-slung transformer so that the body is relatively empty compared to
contemporary electric locomotives. Much of the engineering was derived
from the research and operational experience of the APT-P.