On May 11th this year, Keio Electric Railway celebrated the 30th anniversary of the EMU 8000 series operation. I recently found a special anniversary plate displayed on the front of set 8701 train. Congratulations on the 30th anniversary!
To start, let me quickly review the Keio line. It's one of the main transportation arteries in the Tokyo metropolitan area. Connecting Shinjuku and several western suburban cities, the total operating length is 72 kilometers. It carries an average of 1.25 million passengers per day. One of the characteristics of this line is its unique track gauge size... 1,372 millimeters. It's because the Keio line was initially constructed as a tramline same as the Toei-Arakawa and Tokyu-Setagaya lines.
Let's head to the main topic. The 8000 series was launched in 1992 as Keio's first train to adopt the variable frequency drive (VFD) electric control system. 245 cars in total were built by Nippon Sharyo and Tokyu Sharyo. As you know, the RPM and torque of induction motors are adjusted through frequency and voltage in the VFD system. Coupled with a regenerative braking system and vehicle weight reduction, electricity consumption of the 8000 series was reduced by 45 percent compared to the prior trains. As I posted before, my grandfather, who passed away in 1999, was an engineer of Keio Electric Railway. He introduced many trains during his assignment. I think he's also celebrating the 30th anniversary of the 8000 series on the other side. Time passes by so quickly.
