こういう器具の名前が気になるhttps://en.wikipedia.org/wiki/Conductor_(rail)#/media/File:Zugführer_Abfahrsignal.jpg
baton なのかなhttps://blog.railwaymuseum.org.uk/the-piece-of-plastic-that-keeps-the-rail-network-running/
思考の /dev/null
