Sorry to ask but what do you mean by VHF?
It's either Virgin High Frequency or Very High Frequency, I'm not actually sure which. But it's the new timetable that was introduced onto the WCML a couple of years ago once the 390s and 221s were fully in place to take advantage of the higher top speed available to them and also the higher unit availability (more trains available per day) to enable an increasing of service frequency and speed along the whole route. However it has had knock on effect for other operators on the WCML making their paths much more restricted.