The vast marshalling yards found near many European borders are a reminder of how the continent’s railways operated for decades after the second world war. Freight trains crossing the borders would screech to a halt on one of the sidings and wait – often for hours – while one locomotive and crew were detached from the train. Another, from the next country’s monopoly national railway, would then couple on.

The ritual was a result of the insularity of the continent’s state-owned national rail monopolies. Each developed its own electrification and signalling system, partially to reduce the risk of neighbours’ rolling stock being used to support a future military invasion.