I won't go into the full details because we discussed them here last year. But the Circle line isn't going to be a circle any more. The circle is being broken, at Edgware Road, and one end yanked out to Hammersmith. Like a tape measure. Like a yo-yo. Like one of those lasso things that cowboys used to wave. But not like a circle.
Because circles are bad. Circles go round and round, in circles, so they never terminate. And terminating is important, otherwise it's very difficult to keep trains to timetable. All reliable underground lines terminate, especially those which share tracks with other underground lines. But a circle doesn't terminate, so it's not very reliable, and it only takes one little disruption somewhere and the entire line is shot to buggery. So circles are bad.
Here's how TfL announced the change in one of their press releases:
OK, I understand the rationale. But a circle that starts and finishes? That's just wrong. Starting and finishing are not things that circles do. Not ever. Maybe I should throw all my geometry books away.
Curiouser and curioser. Here's what Howard Collins, who's a top tube bod, says:
"Shown as a circle" on the tube map? Really? But it's not even a circle at the moment. It's a sort of elliptical bottle shape. It's a ring with squashed-in bits. It's sort of oval-ish. Of all the things it is, it most definitely isn't a circle. And it's going to be even less like a circle in the future.
There are many better names that the new line could have. The Spiral line, for example. The Hammersmith & Not City. The Extended Circle. I'm even quite tempted by the Paperclip. I'm sure you can think of a better name for a non-circular shape like this. Here, have yourselves a comments box in which to write some better ideas.
But none of this matters. The new line, that neither looks like a circle nor is a circle, will still be called the Circle line. It would be churlish to change the name now that Londoners have had 60 years to get used to it. It would also be bloody expensive. The last thing TfL wants is to go round changing every single sign on the entire tube network which mentions the word 'Circle' to something else. Keeping the name is a value for money solution, even if not a topological one.
So, come December, who fancies explaining all this to tourists? I bet they won't work it out from the tube map (which may well look something like this). It's called the Circle line, but it isn't a circle. It starts at Hammersmith and heads to Edgware Road, and then it carries on... to Edgware Road. Then it turns round and goes back again. On the way back it goes to Paddington, one stop after Edgware Road, and later to Paddington, one stop after Edgware Road, but they're different Paddingtons. Just look out for the train which says "Circle Line" on the front. It'll take you to Hammersmith, either fairly quickly or very slowly. Because the Circle line threads through itself like a shoelace. Because the Circle line isn't actually a circle. Yes, it'll be crystal clear. No, really, what could go wrong?
When is a circle not a circle?
