History
Karuizawa Station opened on 1 December 1888 as the terminus of the JGR line from Ueda. On 1 April 1893 the line was extended south to Yokokawa with an Abt-rack section over the Usui Pass, completing the trunk route between Takasaki and Naoetsu that was named the Shin'etsu Main Line in 1909. Helper locomotives were coupled at Karuizawa for the steep climb until JNR introduced double-headed EF63 adhesion working on 15 July 1963, ending Abt operation on 30 September. JR East took over on 1 April 1987. With the Nagano Shinkansen opening on 1 October 1997 the Yokokawa–Karuizawa section was abolished, and Karuizawa–Shinonoi passed to the Shinano Railway.
History summarized from Japanese & English Wikipedia · last reviewed 2026-05-18.
Notes
On 11 May 1912 the Yokokawa–Karuizawa Abt section was electrified at 600 V DC third-rail — the first electrified trunk-line section in Japan.