So at Manningtree Station, next to platform 3 (if I'm correct) is another platform. There is an old-looking rail line, and it seems to be the terminus. Half of the platform is accessible from platform 3, the other isn't. It doesn't look electrified, although there is a sing cable over it. It curves into platform 1. What was this used for? Do any trains (for emergency, probably) terminate there or go there? I have seen a rail cleaner, but that's it.