>>1570766>>1570767>>1570785>>1570786>>1570787They were only big by our standards, most countries, even in Europe, had far longer goods trains.
If only coal mines updated their loading facilities, we could have had huge trains pulled by beasts like the LNER P1 (pic related) at 60+mph.
However, because of the tiny, low capacity, and effectively un-braked wagons, the trains that these could pull were longer than the passing loops on the mainline. So these were scrapped instead.