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]
New Measurement Train, the British equivalent of Doctor Yellow, used to assess the condition of track
TGV Iris 320, the French counterpart of Doctor Yellow, used to monitor the condition of the French tracks (mainly the high-speed railways
LGV) used by high-speed trains, as well as
High Speed 1 in the United Kingdom.