A Trough Girder Bridge at Hanawa
The Watarase Keikoku Railway Karasawa Bridge (わたらせ渓谷鐵道唐沢橋梁) is a steel single-span bridge built in 1936 at Hanawa, Azuma-cho, Midori City, Gunma Prefecture, and was registered as a Registered Tangible Cultural Property (structure) on November 2, 2009 (Agency for Cultural Affairs).
The Agency for Cultural Affairs records a steel single-span bridge 3.4 metres long, with abutments, registration number 10-0289.
The Ashio Copper Railway
According to Watarase Keikoku Railway, the Ashio copper mine, bought by Furukawa Ichibei in 1877, grew to produce half of Japan's copper, more than horses and a horse tramway could carry, so a railway was built from Kiryu to Ashio. The Ashio Railway opened to Omama in 1911, reached Ashio in December 1912 and was completed to Ashio Honzan in 1914. Nationalised in 1918 as the Ashio Line, it has been run by Watarase Keikoku Railway since 1989.
The Watarase Keikoku Railway Karasawa Bridge lies about 2,800 metres south-west of the Konakagawa Bridge (Agency for Cultural Affairs).
Value as a Registered Cultural Property
The Watarase Keikoku Railway Karasawa Bridge was registered as a structure that has become a model of design. The Agency for Cultural Affairs records a standard Type 827 trough girder: to gain headroom below, the rails sit between two I-beam girders on cross-beams instead of on sleepers laid on top.
What to Look For
The Agency for Cultural Affairs describes a single-track steel bridge 3.4 metres long whose trough girder carries the track low between the beams.
Watarase Keikoku Railway's pamphlet places the Watarase Keikoku Railway Karasawa Bridge roughly midway between Hanawa and Nakano stations, behind the last house at the Ashio end of the old Hanawa post town; its 2.4-metre girder holds the rails between H-section beams.
Visiting
Trains cross the Watarase Keikoku Railway Karasawa Bridge about a minute after leaving Hanawa Station (Watarase Keikoku Railway). Watarase Keikoku Railway notes that all of its registered structures can be seen from the train.
Do not enter the tracks; view it from the train, the station or nearby roads. It is located at Hanawa, Azuma-cho, Midori City, Gunma Prefecture. Of the line's 38 registered structures, the 26 in Gunma and 11 in Tochigi are gathered on the group pages Watarase Keikoku Railway (Gunma Section) and Watarase Keikoku Railway (Tochigi Section).
- 📍 Plan Your Visit to Gunma
- Find tours, activities & transport passes near Watarase Keikoku Railway Karasawa Bridge
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Q&A
- When was it built?
- In 1936 (Agency for Cultural Affairs).
- How is it built?
- A steel single-span bridge 3.4 metres long, with abutments (Agency for Cultural Affairs).
- What is a trough girder?
- A girder that holds the rails between two main beams on cross-beams, saving headroom below (Agency for Cultural Affairs).
- Where can it be seen?
- Trains cross the Watarase Keikoku Railway Karasawa Bridge about a minute after leaving Hanawa Station (Watarase Keikoku Railway).
- When was the Watarase Keikoku Railway Karasawa Bridge registered?
- On November 2, 2009.
Basic Information
| Name | Watarase Keikoku Railway Karasawa Bridge (わたらせ渓谷鐵道唐沢橋梁) |
|---|---|
| Location | Hanawa, Azuma-cho, Midori City, Gunma Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2009/11/02 (Heisei 21) |
| Quantity | 1 structure |
| Dimensions | Steel single-span bridge, length 3.4 metres, with abutments |
| Owner | Not listed in the national database (line operated by Watarase Keikoku Railway Co., Ltd.) |
| Public Access | Visible from the train |
References
- Watarase Keikoku Railway Karasawa Bridge (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00007862
- Registered Tangible Cultural Properties (Watarase Keikoku Railway, in Japanese)
- https://www.watetsu.com/sightseeing/culture.php
- Pamphlet: Railway Heritage from the Train Window, map notes (Watarase Keikoku Railway, in Japanese)
- https://www.watetsu.com/assets/pdf/sightseeing/culture_yukei_des02.pdf
- History (Watarase Keikoku Railway, in Japanese)
- https://www.watetsu.com/company/history.php
Last verified: 2026.10.12
