Is there a minimum age for a child travelling alone on a train?

[PuppyMonkey]

DD1 (who is 14) may have to get via train from Derby to Berwick on Tweed later this month (thinks it's East Coast line, have to check it all out etc). It's all for complicated if quite boring reasons, we're just thinking about it at the moment.

Grandma is going to put her on the right train at Derby.
She will have to change once at York.
Me and DP will meet her at Berwick on Tweed.

She is very bright and quite sensible, not particularly streetwise, but she gets bus and stuff on her own at home. She is confident she'd be able to find the right platform when she has to do the change at York.

I just had a thought last night when I had insomnia that this is a really terrible thing for her to do on her own and now I'm not so sure about letting her do it!!!!????

And anyway, is there a minimum age for kids travelling alone on a train?

WWYD?

Buses are annoying aren't they - they don't stop at every stop and you have no warning/clues as to where the stops are.

I remember starting at university and all the posh kids who were used to being ferried around by mummy/daddy had no idea how to catch a bus. It was quite funny seeing groups of them standing at the bus stop all looking puzzled as one bus after the next whizzed past because they hadn't signalled that they wanted it to stop.

So it's a good thing for teenagers to start learning about how public transport actually works...

We used to take the train to town shop all day and catch the train back at that age (long before mobiles) she will be fine.
Large stations are much better to change at than small ones, they are staffed and have proper updated information boards.
I wish we'd had the digital boards where I used to commute from. We lost our staffed signal box and therefore our announcements, you just stood there and hoped.