We drove through the night on Friday to see rare wildlife in the woods at dawn. Mid-morning we were up watching the skiers on Cairngorm Mountain. They get them up the mountain with a funicular railway. You can see it snaking upm to the ski station on the second picture. In fact, there are two trains that are strung together on a long cable. One goes up whilst the other comes down. Hence gravity is doing a lot of the work of lifting the lower train as the upper train falls. The falling train gives its gravitational potential energy to the rising train. It is a single track but there is a short section of double track half way. There is no other place where they will meet because they are tied by a cable.
