Apologies if the answer to this is available elsewhere...

Is Fast Track security only available at LHR T5 at the Zone H secuity lanes (close to CW and F check-in counters)? Or is there a Fast Track lane at the regular security lanes as well?

I ask because whenever I have used the Zone H Fast Track security, there is always a big queue and so I am never convinced that it is actually that 'fast'.