It's fun for me to find rare trains on railway tracks as a trainspotter. No matter how painful things are, rare trains make me happy. Trainspotters are carefree people, aren't they? I’m going to show you a surefire topic for old-school trainspotters like me today.
The subway Tokyo Metro Namboku line penetrates Tokyo Metropolis from south to north. Connecting Meguro and Akabane-iwabuchi, the total operating length is 21.3 kilometers. Many trains are directly operated onto the Tokyu-Meguro, Saitama Railway and other lines. In addition to that, the section between Meguro and Shirokane-takanawa is shared with the Toei (Tokyo Metropolitan Government) Mita line.
To operate the Namboku line on timetable, 23 train-sets in total should be provided by Tokyo Metro. They all look the 6-car trains, but there is one train-set of exception if you observe them carefully. That's Set 9109 of the EMU 9000 series, which is composed of 8 cars. You can confirm it, if you count the number of air-conditioners installed on the roofs of the train (see the photo below). Set 9109 was originally built in 1995 as a 6-car train. Two new cars were then added to this train-set, and it became an 8-car train in 2023. According to Tokyo Metro, 14 more train-sets will be changed from 6 to 8 cars to increase transport capacity; however, I haven't heard from Tokyo Metro recently. As a result, Set 9109 is now an extra rare train-set consisting of 8 cars. It’s really fun for me to perceive a fine difference between these trains.