Theyre mostly multiple units up there now, not many loco,s with numbers, and you actually have to see them.
Get a copy of Ian Allan, abc loco spotter book, and just mark off all the unit numbers you see.
Or alternatively you could stick thin slivers of bamboo under your fingernails, and burn yoursel repeatedly with a cigarette, while having your eyeballs gnawed out by a pack of angry weasels.
Hmmm - that's a pretty tough choice actually
Problem being youre not allowed to smoke on a train anymore,or the Fag Police will have you.