For reasons that you (probably) know, I thought you might enjoy this:
I was recently in central London (more about that later, maybe) and needed to get to Heathrow. I took the Piccadilly Line tube from Russell Square. We proceeded one stop, to Holborn, where we stopped for a long while, after which the engineer announced -- these things always come out garbled, so it's hard to say for sure, but it sounded like -- "Ladies and gentlemen, the ground controller has informed me that the train two stops ahead of us tried to take the turn too rapidly, and now can't shut its doors. We'll wait here until further instructed." The man was true to his word, for there we did, indeed, wait, until eventually the doors closed and we moved forward one more stop, to Covent Garden, where, once more, we waited. After a while came another announcement: "Ladies and gentlemen, the ground controller ... one stop ahead of us ... further instructed." Eventually, it was announced that the bothersome train was now clear of the tracks, but that we would wait further until the ground controller gave us "the green aspect". Well, that sounds to me like some sort of metaphorical term for jealousy, but, whatever it is, we were apparently given it, for, in due time, we went ahead, and then proceeded without further incident until somewhere in the vicinity of South Kensington, when there came a further announcement. It was (with the same caveat as above): "Ladies and gentlemen, owing to the nature of this train, we will not be running past Northfields." That was all -- no further clarification of whether this meant "owing to the fact that this train is running behind schedule", or "owing to traffic congestion", or "owing to the fact that the wheels are about to fall off", just "owing to the nature of this train" 1; and then the announcement "This is a Piccadilly Line train to Heathrow Airport, Terminals 1, 2, and 3" became "This is a Piccadilly Line train to Northfields", and that was all the explanation we ever got.
1 I've been sensitive to this kind of wording ever since a Delta airlines attendant once announced to those of us waiting at the gate that the incoming flight would be arriving late since it had "broke[n] mid-flight" -- an explanation which she apparently expected us to accept with calm equanimity.