<Image removed at request of Transport for London, December 20, 2019>

Surprisingly, I haven’t seen anything like this on the Internet before, so I went and made my own. It’s been compiled from various sources (both official and unofficial), so the quality is a little variable, but it’s still fun to look at! 

I’ve made the dimensions of the circle/ring consistent across all the different versions, so the height and width of the crossbar shrinks and grows over the years. The graphic is by no means exhaustive, but I think I’ve covered all the major revisions over the years. Let me know if I’ve missed a big one!

Of particular interest is the subtle tweaking of the negative space in more recent times (from the 1970s onwards), and the sheer number of roundels in use today.