Tom Scott

After 140 years, this old technology still keeps trains safe (2022x10)

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"Anderson's Piano" is a set of wires and signals at the Pass of Brander, near Falls of Cruachan in Scotland, that try to detect when there might be a boulder on the track. They're 140 years old, and so far no-one's been able to find a better solution — but they're working on it.