>>1124391You should save on tunnel costs since the bogies can be made smaller and trains shorter, though the Oedo line got bungled anyway lol
That posed another problem with the Oedo line. In the earlier years, there was no aircon on the trains due to difficulties with making a unit that thin. Eventually when they did get made, it was limited to about 30 kW per carriage owing to size constraint, so they try to compensate by running at a lower official set point of 23°C
Marunouchi and Ginza line trains over at the Eidan had a similar issue, but managed to nick some 23 kW units from Toshiba for 46 kW per carriage at some point, upgrading from the 32 kW install
