Today was a rather wiggly journey into work. The train crossed from the up slow to the up fast (as usual) at Hither Green. (Left to right as you look, travelling up the screen. Remember, real railways run on the left). But then we cross back to the up slow at the first crossover at Park's Bridge Junction, only to cross straight back to the up fast at the second crossover.
I've been on trains before that have crossed twice (Canon Street trains making a brief trip onto the up fast to avoid having to wait behind a train trying to get into Lewisham, which is the route diverging to the right you can see next to the first crossovers at Park's Bridge junction, with a train on it), but I don't think I've ever been on one that made three changes. The reason seemed to be to get ahead of a train from Hayes that was on the up fast, but they could have avoided the three way wiggle either by holding it on the Hayes branch, or not crossing us over at Hither Green.
Nevermind. If they really want to get silly, we could have gone back and forth between Grove Park and Hither Green, and had another trip forth and back after New Cross.