A comforting story for any of you who despair over working in the chronically value-destroying, customer-disappointing, economically perverse world of air transport.
I may have this wrong (if you read the link above you'll sympathise with me) but it seems that the private-sector leasing company that provides coaches to British train companies has so much market power that because it's now subject to a monopoly investigation it's declining to provide enough coaches. This, by the way, is a company whose customers have their purchases guaranteed by Her Majesty's Government! Not even British Airways gets that.
Fortunately, here in Flight's office, I have colleagues on Railway Gazette International who have been able to explain to me what's going on.