Shinkansen
Gauge Change Train

This is the name for the concept of using a single train that is specially designed to travel on both 1,067 mm (3 ft 6 in) narrow gauge railway lines and the 1,435 mm (4 ft 8 + 1 ⁄ 2 in) standard gauge used by Shinkansen train services in Japan. The trucks/bogies of the Gauge Change Train (GCT) allow the wheels to be unlocked from the axles, narrowed or widened as necessary, and then relocked. This allows a GCT to traverse both standard gauge and narrow gauge tracks without the expense of regauging lines.

Three test trains have been constructed, with the second set having completed reliability trials on the Yosan Line east of Matsuyama (in Shikoku) in September 2013. The third set was undertaking gauge changing trials at Shin-Yatsushiro Station (on Kyushu), commencing in 2014 for a proposed three-year period, however testing was suspended in December 2014 after accumulating approximating 33,000 km (21,000 mi), following the discovery of defective thrust bearing oil seals on the bogies. The train was being trialled between Kumamoto, travelling on the narrow gauge line to Shin-Yatsushiro, where a gauge changer has been installed, so the GCT could then be trialled on the Shinkansen line to Kagoshima. It was anticipated the train would travel approximately 600,000 km (370,000 mi) over the three-year trial.

A new "full standard" Shinkansen line is under construction from Takeo Onsen to Nagasaki, with the Shin-Tosu – Takeo Onsen section of the Nishi Kyushu Shinkansen to remain narrow gauge. GCTs were proposed to provide the Shinkansen service from the line's scheduled opening in fiscal 2022, however with the GCT now being cancelled, JR Kyushu has announced it will provide an interim 'relay' service.
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