I think London commuter trains generally finish up around that time. This is fairly typical for commuter trains in general, really; a last train time of midnig

I think London commuter trains generally finish up around that time. This is fairly typical for commuter trains in general, really; a last train time of midnight to 1 am, resuming around 5am, is common. 24 hour commuter trains are relatively rare, as the volume isn't there and they tend to do track maintenance at night.