Tōbu Ogose Line

The line did not begin as part of Tōbu. It was promoted by a local company, the Ogose Railway, which was granted its railway licence on 22 September 1927 and was formally established on 28 September 1928. The company opened its first section, from Sakado to Komagawa, on 17 February 1932, but this initial 5-kilometre stretch carried freight only and had no passenger service.

Passenger operations began two years later. On 16 December 1934 the line was extended onward to Ogose and passenger trains started running over the whole route. Intermediate stations were added as the line settled into service: Nishi-Ōie Station opened on 28 February 1936 and Bushū-Nagase Station on 1 October 1938.

On 1 July 1943 the Ogose Railway was absorbed by Tōbu Railway, and the route became the Tōbu Ogose Line. Wartime conditions soon interrupted it: from 10 December 1944 the entire line was suspended after the military designated it a non-essential line. Service did not resume until 1 December 1945, and on the day operations restarted Ōie Station was closed (the Japanese source notes that the exact closure date is disputed).

In the post-war years the line was modernised. It was fully electrified on 23 July 1950 at 1,500 V DC. On 1 February 1959 Morido Station was closed, and on 1 October that year centralised traffic control (CTC) was commissioned on the line — the first use of the system anywhere on the Tōbu network.

As with many local lines, freight gradually fell away. Freight service between Nishi-Ōie and Ogose ended on 21 February 1984, and the remaining freight working between Sakado and Nishi-Ōie ceased on 1 August 1984, leaving the line carrying passengers only. A modest capacity improvement followed on 25 August 1987, when the Bushū-Nagase–Higashi-Moro section was double-tracked.

More recently the line's operation has been streamlined for its commuter role. From the start of the revised timetable on 14 June 2008 the Tōbu Ogose Line switched to driver-only (one-man) operation across its whole length. Today it functions as a short feeder route, linking the Tōjō Line trunk at Sakado with the town of Ogose and the JR Hachikō Line at its northern end.

• 192722 September: a railway licence is granted to the Ogose Railway.
• 192828 September: the Ogose Railway company is formally established.
• 193217 February: the Ogose Railway opens its first section, Sakado–Komagawa (about 5 km), for freight service only.
• 193416 December: the line is extended to Ogose and passenger service begins over the whole route.
• 193628 February: Nishi-Ōie Station opens.
• 19381 October: Bushū-Nagase Station opens.
• 19431 July: the Ogose Railway is absorbed by Tōbu Railway and the route becomes the Tōbu Ogose Line.
• 194410 December: the entire line is suspended after the military designates it a non-essential line.
• 19451 December: full service resumes; Ōie Station is closed (the JA source notes its exact closure date is disputed).
• 195023 July: the line is fully electrified at 1,500 V DC.
• 19591 February: Morido Station is closed. 1 October: CTC (centralised traffic control) is commissioned — the first use of the system on the Tōbu network.
• 198421 February: freight service between Nishi-Ōie and Ogose ends. 1 August: freight between Sakado and Nishi-Ōie ends, leaving the line passenger-only.
• 198725 August: the Bushū-Nagase–Higashi-Moro section is double-tracked.
• 200814 June: the line switches to driver-only (one-man) operation across its whole length, from the start of the revised timetable.