🌐EnglishEnglishBahasa IndonesiaDeutschEspañolFrançaisItalianoNederlands한국어中文日本語EntityQ855591· pop 16· linked from 273 articlessignalling block systemsystem which enables the safe and efficient operation of railways to avoid collisions between trainsAvailable in 15 languagesEspañolFrançaisDeutsch中文日本語ItalianoBahasa IndonesiaCatalanCzechGalicianLombardConnectionsInternational Standard Book NumberEntity2012 Summer OlympicsEntityCategoriesRailway signalling block systems