Tobu 20000 series

• 20000 series: 13 x 8-car sets introduced from March 1988 • 20050 series: 8 x 8-car sets introduced from December 1992 with 5-door cars • 20070 series: 3 x 8-car sets introduced from March 1997 • 20400 series: 4-car sets introduced from 2018 for the Tobu Utsunomiya Line ==20000 series==

A total of 104 vehicles Formation Trains are formed as follows, with six motored ("M") cars and two non-powered driving trailer ("Tc") cars. The M1 cars are each fitted with one scissors type pantograph. ==20050 series==

A total of 64 vehicles (8 eight-car sets, numbered 21851 to 21858) were introduced on 29 December 1992 on Tobu Isesaki Line (present-day Tobu Skytree Line) and Tokyo Metro Hibiya Line inter-running services. These sets feature two five-door cars at each end, and also LED destination indicators. These sets have VVVF control. Formation Trains are formed as follows, with six motored ("M") cars and two non-powered driving trailer ("Tc") cars. The M5 and M7 cars are each fitted with one scissors type pantograph. Interior Passenger accommodation consists of longitudinal bench seating throughout, with seats for three persons between each pair of doors in the five-door cars. Seat width is per person for the three-person bench seats in five-door cars and per person for the ten-person bench seats in three-door cars. As with the 9050 series EMUs introduced around the same time, these sets featured LCD passenger information screens above the doorways, but these were subsequently removed. ==20070 series==

These are eight-car sets that were introduced from 25 March 1997 to cope with an increased service frequency, of which 24 vehicles (three eight-car sets, numbered 21871 to 21873) were built. These sets feature three-door cars throughout, and also LED destination indicators. These sets have VVVF control. Formation Trains are formed as follows, with six motored ("M") cars and two non-powered driving trailer ("Tc") cars. The M1 and M3 cars are each fitted with one single-arm pantograph. Interior Passenger accommodation consists of longitudinal bench seating throughout. These sets feature three-colour LED passenger information displays above alternate doorways. ==20400 series==

The 20400 series are four-car sets for Tobu Nikko Line and Utsunomiya Line operation north of Minami-Kurihashi Station. The first trains entered revenue service on 3 September 2018. Formation Trains are formed as follows, with two motored cars and two non-powered trailer cars. Car 1 ("Tc2") and 4 ("Tc1") are former 20000 series cars built by Alna Koki in 1988, and cars 2 ("M2") and 3 ("M1") are former 20070 series cars built by Tokyu Car in 1997. Some sets will incorporate former 20050 series cars, which will be converted from five doors to three doors per side. The M1 car is fitted with two single-arm pantographs. Interior Passenger accommodation consists of longitudinal bench seating throughout. The interior is based on the 70000 series design. File:Tobu-24433 Inside.jpg|General interior view, July 2021 File:Tobu-24433 Inside Priority-Seats.jpg|Priority seating, July 2021 File:Tobu-24433 Button Inside.jpg|Passenger door buttons, July 2021 ==Withdrawal and refurbishment==

The 20000 series trains began to be replaced by new 70000 series trains from 7 July 2017. The first sets to be withdrawn, sets 21813 and 21809, were removed for scrapping in July 2017. Some of the 20000 series trains are also refurbished as 20400 series to replace 8000 series trains. The five-door 20000 series trains are being withdrawn so that platform doors can be installed on Tokyo Metro Hibiya Line stations. Transferred vehicles 20000 series cars have been transferred to Alpico Kotsu for use on the Kamikōchi Line, with rebuilt cab ends, where they have replaced life-expired former Keio 3000 series trains. ==References==