Great Western Coffee Shop

Thank goodness this turned out to be hypothetical.

19:30 from Paddington ... usual crush but I got on early, put my very large indeed and heavy bag in the back of the bottom luggage rack in "B" and sat in what seemed like the only unreserved seat therein ;) . More people, more luggage piled in .. and as we neared Didcot I noticed a bloke locking his Brompton to the rack and (I think) he headed off for the buffet.

Coming in to Chippenham and ... I found I couldn't [easily] get my bag out.   Well - OK - I struggled and did get - but what should I have done if I hadn't been able to?

They probably would have weighed and measured your luggage, declared it to be in excess of that permitted, and levied some form of fine, fee, penalty or surcharge !
Luggage space is VERY last century you know !

Well......I would have unfortunately delayed the train, by opening the exterior door closest to luggage rack & refused to close it / alight until train manager sorted out the problem - by making announcement requesting said Brompton owner to return to his bike.

Yep says it all, about the new railway use as few coaches a possible and cram the passengers (customers) in. I am sure the "bean counters" would love it if everytrain was an OMO 153. Very little track wear, lot less fuel etc.

Just a thought should the Brompton owner have padlocked his bike to the luggage rack? Don't the Bye Laws say anything about that, if only not obstructing the gangway.

indeed, you aren't meant to lock your cycle to anything.

I was returning from London a few weeks back and two chaps decided to put their two bikes in the end vestibule of coach H and sit in coach G with the usual "it's okay we can sit here" conversation. They didn't stay long as a member of train crew came down the carriage announcing that the train won't be going anywhere until the bikes were removed from the vestibule and taken to the correct place in the front power car.

A Brommie isn't really a cycle (as it's not in the cycle space) in train terms, it's just another form of luggage. But yes, you probably shouldn't lock your luggage to anything either...