Eagle
Established Member
It makes more sense using one class 90 than 2 57's under the wires
You're confusing two different things there.
The 57s were used for hauling Pendolinos off the wires, mainly to Holyhead but also on a few diversions (such as via Settle). Doesn't happen regularly anymore.
The 90s are used to haul the rake of Mk3 vehicles that Virgin acquired following the loss of a 390 at Grayrigg in 2007, and that has continued to be used on and off for extra timetabled trains (mainly on Fridays) as well as charter hire.