#9 Massive Coal Loading_ How 4 Wagons Load 32 Tons Instantly! How Coal Power Station Merry-Go-Round Trains Really Worked. For decades, Britain’s coal-fired power stations relied on one of the most efficient freight systems ever devised — the Merry-Go-Round coal train. In this video, we take a close look at how these remarkable trains worked, moving millions of tonnes of coal directly from colliery to power station without ever stopping. From bottom-discharge wagons and continuous loading, to pur