Single-vault station
The single-vault deep underground station is a type of subway station.
Overview
The construction of a single-vault station consists of a single wide and high underground hall, in which there is only one vault (hence the name). The first single-vault stations in the USSR were built in Leningrad in 1975: Politekhnicheskaya and Ploshchad Muzhestva. Also in Saint Petersburg was built the first and so far the only two-level single-vault transfer station in Russia: Sportivnaya.
In the Moscow Metro there is only one deep underground single-vault station, Timiryazevskaya, in addition to several single-vault stations at shallow depth. In the Nizhny Novgorod Metro is 4 stations: Park Kultury, Leninskaya, Chkalovskaya and Kanavinskaya. In the Saint Petersburg Metro all single-vault stations are deep underground, for example Ozerki, Chornaya Rechka, Obukhovo, Chkalovskaya, and others. Most of the underground stations of the Washington D.C.'s Metro system are single-vault designs, as are all the single-line vaulted stations in the Montreal Metro. In Prague Metro, there is one underground station built as single-vault, Kobylisy.