Central Japan Railway Co. (JR Tokai) offers reporters a peek Sept. 27 of a “Doctor Yellow” inspection train at the Oi rail yard in Tokyo’s Shinagawa Ward. The train is due to be retired in January. (The Asahi Shimbun)

It may be the end of the line for Doctor Yellow trains, but before they are retired in January train buffs might like to know what they are like inside.

Quite a lot is different, it turns out. 

The trains got their nickname from their distinctive yellow and the diagnostic role they play in ensuring that Shinkansen services operate safely.

On Sept. 27, Central Japan Railway Co. (JR Tokai) offered reporters a peek inside a Doctor Yellow train at the Oi rail yard in Tokyos Shinagawa Ward.

The trains are immensely popular. 

“They just make people happy when they see them,” said a company maintenance official. The trains are scheduled to retire due to obsolescence.

JR Tokai and West Japan Railway Co. (JR West) each own one Doctor Yellow train, officially known as Shinkansen Multiple Inspection Train. The two special trains alternately run between Tokyo and Hakata once every 10 days to inspect the tracks and overhead wires.

JR Tokai plans to retire its Doctor Yellow train in January while JR West will do so in 2027 or later. 

The first and seventh cars of the seven-car train have square windows under the headlights, which are not found on commercial cars, to house surveillance cameras.

The fourth car has under-floor equipment to measure rail distortion as small as 0.1 millimeter.

Together with the first car, which checks electrical systems such as trolley lines, the fourth car is considered the core part of Doctor Yellow.

Takashi Okamoto, a member of JR Tokais track maintenance section, said, “The Doctor Yellow is the ‘pillar’ of safety. In addition, it has made people who have seen it happy. We intend to complete inspections with the train until the end."