>yes the first coupling must bear the load of the full train This is only the case with a standard locomotive arrangement. The trains involved here appear to

>yes the first coupling must bear the load of the full train This is only the case with a standard locomotive arrangement. The trains involved here appear to be EMUs (electric multiple units), which have motors in most of the bogies (wheel assembles). Therefore, the lead car isn't pulling the whole thing. Even when trains aren't EMUs, often you have a "push-pull" arrangement, such as the French TGV which has a power car at each end.