Doctor Yellow
Doctor Yellow is the nickname for a series of high-speed maintenance of way trainsets that are used on JR Central's Tokaido Shinkansen and JR West's San'yō Shinkansen lines. The trains have special equipment on board to monitor the condition of the track and overhead wires, including special instrumented bogies and observation blisters. Line inspection is carried out at full speed, up to on the Tōkaidō Shinkansen and on the Sanyō Shinkansen. Doctor Yellow trains make three round trips between and Hakata Station every month. Depending on the day, trains follow the stopping pattern of either Nozomi or Kodama trains. A similar type of diagnostic train called East i is operated by JR East on the Tōhoku Shinkansen.
"Doctor" in the name "Doctor Yellow" refers to their test and diagnostic function, and "Yellow" refers to the bright yellow livery they are painted in. The original color scheme of yellow with a blue stripe was created by reversing the colors used by track-recording cars on Japan's narrow-gauge railways. Some Doctor Yellow sets are painted with a green waistline stripe rather than a blue one. In build and appearance, they resemble the production, passenger-carrying Shinkansen trains they are based on.
Because the schedule for this train is not made public, witnessing a Doctor Yellow in operation is a matter of chance. As a result, seeing one is said to bring the witness good luck or happiness. Railfans have set up websites and social media accounts to predict Doctor Yellow's arrival dates and times at stations along the route.
On 13 June 2024, JR Central announced that they would terminate use of Doctor Yellow trains on the Tōkaidō Shinkansen line in January 2025, with plans for farewell events – including commemorative train rides, displays, and souvenirs – to be announced at a later date. At the same time, JR West announced plans to retire their trains after 2027. They are scheduled to be replaced with commercial N700S Series Shinkansen trains that incorporate inspection and observation equipment.
List of Doctor Yellow trains past and present
For Tōkaidō and Sanyō Shinkansen
- Non-powered track recording cars :
- * 921-1: Built in 1962, and retired in 1980.
- * 921-2: Converted in 1964 from former MaRoNeFu 29-11 sleeping car, and retired in 1976.
- 0 series type :
- * 922-0 : 4-car set converted in 1964 from the prototype set built in 1961, and retired in 1976.
- * 922-10 : 7-car set owned by JR Central. Built in 1974 and retired in 2001.
- * 922-20 : 7-car set owned by JR West. Built in 1979 and retired in 2005.
- 700 series type :
- * 923 : 7-car set owned by JR Central. Delivered in 2000. Retired on 29 January 2025.
- * 923-3000 : 7-car set owned by JR West. Delivered in 2005. To be retired in 2027.
For Tōhoku, Jōetsu, Hokuriku, Hokkaido, Yamagata, and Akita Shinkansen
- 200 series type :
- * 925/0 : 7-car set owned by JR East. Delivered in 1979 and retired in 2001.
- * 925/10 : 7-car set owned by JR East. Converted from former Class 962 test train in 1982 and retired in 2002.
- E3 series type
- * E926 : "East i" 6-car set owned by JR East. Delivered in August 2001.