Osaka Metro New 20 series

Osaka Metro New 20 series is an umbrella term referring to a series of six Japanese city commuter electric multiple units operated by the Osaka Municipal Transport Bureau and later Osaka Metro since April 1990 on the Midōsuji, Tanimachi, Yotsubashi, Chūō and Sennichimae Lines and formerly by Osaka Port Transport System from December 1997 to July 2005. This term comprises the 21, 22, 23, 24 and 25 series sets and by extension the OTS series sets.
==History==
The New 20 series trains were introduced in 1990 to replace aging rolling stock on the various Osaka Municipal Subway lines. The first trains of the series to be introduced were the 22 and 23 series on the Tanimachi and Yotsubashi Lines, both on 25 April 1990. A total of 572 cars were manufactured from 1990 to 1998 by various manufacturers and would end up being used on all lines on the Osaka Municipal Subway, bar the Sakaisuji and Nagahori Tsurumi-ryokuji Lines. Two sets were later manufactured for the Osaka Port Transit System, classified the OTS series in 1997 for use on the OTS Technoport Line. This was short-lived, however; the line was assimilated into the Chūō Line in July 2005 with the OTS series being renumbered as part of the 22 series of trains.
As of 2022, all 572 cars are in service. The trains have been undergoing extensive refurbishment works since 2010 to extend their lifespans.
==Design==
The New 20 series sets use a raked front end with a centrally-mounted dual headlight fixture; these sets feature a "gentle" design that was received well by the public due to its modernity at the time. All sets in the series share a common design, with many elements being reused from the 20 series trains.
==Specifications==
Construction is of a high-strength stainless steel. The sets use early-specification Mitsubishi GTO drives which produce a droning noise which steps up in pitch; these have been largely replaced by Hitachi IGBT drives which produces a high-pitch whine which steps up in pitch. 
Category:Osaka Metro trains
Category:OTS trains
Category:Electric trainsets
Category:Osaka Municipal Subway trains
Category:Alna Kōki locomotives
Category:Hitachi locomotives
Category:Kawasaki locomotives
Category:Kinki Sharyo locomotives
Category:Nippon Sharyo locomotives
Category:Tokyu Car locomotives