Isumi Line - History

History

Plans for the Isumi Line were drafted by the Railway Ministry under Railway Construction Act in 1922. However, the route already had an existing 609 mm (2 ft) gauge human-powered tramway, which had been opened by the Chiba Prefectural government on 15 December 1912 to connect Ōhara and Ōtaki. Local opposition and the deficit situation of the existing line delayed construction, which did not begin until 1925. The tramway was bought out by the Japanese Government Railways in 1927, and the first section of the new Kihara Line (木原線?) was opened on 1 April 1930. The line was extended to Fusamoto by August 25, 1933 and to its present terminus at Kazusa-Nakano on 26 August 1934. As its name implies, the Kihara line was originally intended to connect Ōhara with Kisarazu. However, it was never extended further than Kazusa-Nakano.

In 1954, the first JNR diesel railbus, the KiHa 10000, was introduced on the Kihara Line. Four additional stations were added on June 20, 1960 (Nishi-Ōhara, Nittano, Koyamatsuand Kugahara). However, on September 4, 1968 the line was listed as one of 83 money-losing local lines recommended for closure. The line problems were compounded in the summer of 1970, when heavy rains washed out a portion of the track, causing a suspension of operations from July 1 through October 1. Scheduled freight operations were suspended from October 1, 1974. On September 18, 1981, the line was again recommended for closure.

After the breakup and privatization of the JNR on April 1, 1987, the line came under the control of the JR East.

The Isumi Line came into being on 24 March 1988 following the transfer of the assest of the former Kihara Line to the newly formed third sector operator Isumi Railway Company.

The Isumi Railway has attempted to increase revenues by selling naming rights to stations to local industries, leading to some confusion on the correct station names.