JR Central's Class 923 "Doctor Yellow" set T4 on the Tōkaidō Shinkansen, September 2021

Doctor Yellow (Japanese: ドクターイエロー, Hepburn: Dokutā Ierō) is the nickname for the high-speed test trains that are used on the Tokaido Shinkansen and San'yō Shinkansen. On Shinkansen lines operated by the East Japan Railway Company (JR East), there is an equivalent called East i. The trains have special equipment on board to monitor the condition of the track and overhead wire, including special instrumented bogies and observation blisters.[1][2]

The "Doctor" part of the name is from their test and diagnostic function, and the "Yellow" part comes from the bright yellow color they are all painted. Some have a blue waistline stripe, some a green one. The original color scheme of yellow with a blue stripe (applied to the Class 921 track-recording cars) was created by reversing the colors (blue with yellow stripe) used on 1,067 mm (3 ft 6 in) narrow-gauge track-recording cars.

In build and appearance, they are very similar to production, passenger carrying Shinkansen trains, and line inspection is carried out at full line speed (i.e. up to 270 km/h or 168 mph on the Tōkaidō Shinkansen).

Because the schedule for this train is not made public, witnessing it in action is a case of chance. As a result, seeing Doctor Yellow in operation is believed to bring the viewer good luck.[3]

List of Doctor Yellow trains past and present

For Tōkaidō and Sanyō Shinkansen

For Tōhoku, Jōetsu, Hokuriku, Yamagata, and Akita Shinkansen

Interior (Class 923)


Preserved examples

Preserved Doctor Yellow car 922-26 inside the SCMaglev and Railway Park, March 2011

In popular culture

See also


  1. ^ Wada, Shigeki, "'Dr. Yellow' train keeps line safe, elates spotters", Japan Times, March 11, 2010, p. 3.
  2. ^ Naganuma, Yasukuni; Tanaka, Mamoru; Ichikawa, Kimihiro. "High-Speed Track Inspection Car in New Dr. Yellow" (PDF). Railway Research.
  3. ^ "'Dr. Yellow' lucky Shinkansen shows its belly for 1st time". Japan Bullet. Archived from the original on 2022-08-08. Retrieved 2020-10-14.
  4. ^ "Multipurpose Inspection Train (Dr. Yellow)" (PDF). International High-speed Rail Association.
  5. ^ "「リニア・鉄道館」ファーストガイド" ["SCMaglev and Railway Park" First Guide]. Tetsudō Daiya Jōhō Magazine. Vol. 40, no. 324. Japan: Kōtsū Shimbun. April 2011. pp. 20–33.