>>1593601A design concern with pantographs is the fact that in bad conditions, a pantograph might sway with the wind, or perhaps the train does. This isn't common, but it does happen every so often.
In a high speed train design like the TGV or ICE, high performance pantographs use a system whereby if power is lost from the OHL, the pantograph will lower as a fail-safe. This is because high performance pantographs in Europe use compressed air to adjust the height of the pantograph. The catenary wire is also kept higher in Europe for loading gauge purposes. Single arm designs can lower quickly and give much greater amounts of clearance, preventing potential OHL entanglement.
The Japanese designs don't give the same amount of clearance, and as such put them at higher risk of entanglement incidents, which can bring down several kilometres of catenary wire, which can take days or even a few weeks to repair. In Europe, either rail replacement services would be needed, or unusual train sets hauled by diesel locomotives would be needed to go across the section of damaged catenary.
