Jōhoku Line

The line had its origins in a freight project of the national-railway era. A railway linking Seto with Inazawa was first proposed in 1962, when it was listed among the planned lines under the revised Railway Construction Act. In the 1960s the Japanese National Railways (JNR) drew up a more specific scheme for a freight-only line that would join the Chūō Main Line at Kachigawa to the Tōkaidō Main Line at Biwajima, giving freight trains a bypass around the congested heart of Nagoya. Construction began in March 1976, but it was soon suspended because of the enormous deficits that were then engulfing JNR.

The half-built line lay dormant until the division and privatisation of JNR in 1987, after which it was revived not as a freight route but as a local passenger railway. On 1 December 1989 JR Central, which had inherited the project, applied to the Minister of Transport for authorisation to build the Kachigawa–Biwajima section, then treated as part of its Seto Line and given as 11.7 km. By 23 August 1990 the company had decided that the line would be run not by itself but by a wholly owned subsidiary set up for the purpose — the Tōkai Transport Service Company, later renamed the JR-Central Transport Service Company — which would operate it as a Class II railway business over facilities held by others.

The Jōhoku Line opened in two stages. The first section, from Kachigawa to Owari-Hoshinomiya, entered service on 1 December 1991, and the remaining stretch from Owari-Hoshinomiya to Biwajima followed on 18 March 1993, completing the through route. As built, the line ran 11.2 km and served six stations — Kachigawa, Ajiyoshi, Hira, Otai, Owari-Hoshinomiya and Biwajima — with intermediate connections at Otai to the Nagoya Municipal Subway Tsurumai Line and the Meitetsu Inuyama Line. At its two ends the line meets the Chūō Main Line at Kachigawa and the Tōkaidō Main Line at Biwajima, the same trunk lines its freight-era plan had been designed to link.

The line's operating arrangement reflects how it was financed. The infrastructure was built and is held by the Japan Railway Construction, Transport and Technology Agency (JRTT), and TKJ — the JR Central subsidiary — runs the trains over it as a Class II operator under a long-term lease, with JR Central as the parent that backs the undertaking. (English-language sources often describe the facilities more loosely as belonging to JR Central, the parent company.) Because it was never electrified, the Jōhoku Line is worked entirely by diesel railcars and stands out as the last non-electrified line in Aichi Prefecture. The lease contract under which TKJ pays the construction agency for the use of the line is scheduled to run until 2032.

Despite running close to central Nagoya, the Jōhoku Line has remained a lightly used route, hampered by its isolation from the wider network and the inconvenience of its Kachigawa terminus, which sits apart from the JR Chūō Main Line station of the same name. When the Chūō Main Line's Kachigawa Station was rebuilt in 2009, space was deliberately set aside there to allow the Jōhoku Line to be connected into the JR station in the future, a long-discussed step that would let its trains run through toward central Nagoya. For now the line continues in its modest role as a diesel-worked local railway skirting the northern and western edges of the metropolis.

• 1962A railway linking Seto and Inazawa is proposed, listed among the planned lines under the revised Railway Construction Act.
• 1976March: the JNR begins construction of the line as a freight-only route linking Kachigawa (Chūō Main Line) and Biwajima (Tōkaidō Main Line); work is soon halted because of JNR's huge deficit.
• 19891 December: JR Central applies to the Minister of Transport for authorisation to build the Kachigawa–Biwajima section (11.7 km), then treated as part of its Seto Line.
• 199023 August: JR Central decides the line will be operated by a 100%-owned subsidiary set up for the purpose — the Tōkai Transport Service Company, later the JR-Central Transport Service Company.
• 19911 December: the Jōhoku Line opens between Kachigawa and Owari-Hoshinomiya.
• 199318 March: the Owari-Hoshinomiya–Biwajima section opens, completing the 11.2 km line of six stations.
• 2009The Chūō Main Line's Kachigawa Station is rebuilt, with space set aside for a possible future connection of the Jōhoku Line into the JR station.
• 2032(Scheduled) The lease contract under which TKJ pays the railway-construction agency (JRTT) for use of the line is due to end.