The Class 390 Pendolinos utilised by Virgin Trains are only permitted the top West Coast Main Line (WCML) speed of 125mph when their tilt systems are fully operational; otherwise only the nominal 110mph is allowed. The higher speeds are so-called Enhanced Permissible Speeds or EPS for short.
Rugby was the cause of one of the most significant bottlenecks on the WCML, though, as a whole, much remodelling has taken place in this area, which has seen the ability of the Pendolinos to run at their maximum 125mph be increased significantly. I think the impact of a few Class 90-hauled trains with Mk3 carriages, with their lower maximum speed of 110mph, won't have much of an effect on Virgin Trains' Very High Frequency timetable.
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Why? Class 90 acceleration is top class - better than an Class 43 high-speed train (Intercity 125) when hauling 8 or 9 coaches. The WCML's top line speed of 125mph is only permissible for Pendolinos and Class 221 Super Voyagers when their tilting mechanisms are working. Nothing else. Non-'super' Voyagers (Class 220s) are the lighter but non-tilting variant and are prevented from travelling above 110mph. In terms of speed and acceleration the Class 221s acquit themselves fairly well alongside the Pendolinos, even at a slightly lesser speed. (DB)
Further reading can be obtained by visiting the Railway Performance Society's website.
Click here to learn more about Virgin Train's Very High Frequency timetable.