Origin and applicability of tunnel (semi) transverse ventilation system of underground railway station

No trackway exhaust system has been built in earlier European and American underground railway projects until 1970s, when Subway environmental design handbook recommended overtrack and underplatform exhaust ducts adopted in station configuration, based on Toronto field test in 1975. Since Shanghai underground railway line 1, most of the underground railway lines in China adopt the semitransverse ventilation design scheme. Based on the characteristics of nonscreen door system and screen door system, presents the tradeoff method on the (semi) transverse ventilation scheme versus air conditioning scheme, and deduces the decision formula of economic performance of (semi) transverse ventilation scheme.