Registered Tangible Cultural Properties · Kumamoto

Kumagawa Railway Omizo Bridge

Kumagawa Railway Omizo Bridge: A 1923 Trough Girder in Hitoyoshi

A 4.8-metre steel bridge of 1923 near Hitoyoshi Onsen Station, rails set between two girders on longitudinal timbers, a detail of the earliest standard designs.

Designation Registered Tangible Cultural Properties

Location Kumamoto

The First Registered Bridge out of Hitoyoshi

The Kumagawa Railway Omizo Bridge (くま川鉄道御溝橋梁, Omizo Kyōryō) is a small steel railway bridge in Shiromotomachi, Hitoyoshi City, Kumamoto Prefecture, completed in 1923 and registered as a Registered Tangible Cultural Property on 19 December 2014. It stands about 310 metres east of Hitoyoshi Onsen Station, the first registered structure a Yunomae-bound train crosses.

It is a single steel span, 4.8 metres long, resting on two abutments. The Kumagawa Railway Daiogawa Bridge, also registered, lies about 170 metres further east.

Rails Sunk Between the Girders

What sets the Kumagawa Railway Omizo Bridge apart is where the rails sit. On an ordinary girder bridge, sleepers and rails ride on top of the girders. Here the rails are lowered into the trough between two main girders, an arrangement known as a trough girder. Engineers chose it where clearance beneath the deck was tight: the track stays at the same level while the channel or path below keeps its headroom.

The rails are not fixed directly to the cross members either. They are mounted on longitudinal timbers, a detail the Agency for Cultural Affairs identifies with the very earliest standard designs. Later designs dropped it, which is why this Taisho-era survivor matters.

The bridge was registered as difficult to reproduce. It is under 5 metres long, but its form belongs to a generation of standard details that could not easily be rebuilt today.

What to Look For

Study the girders from the side. Their top edges stand higher than the rails, so the track appears to run inside a shallow steel channel, a profile quite unlike a bridge that simply carries the line on top.

The Daiogawa Bridge is a few minutes' walk away. See the two in succession and you notice that bridges built in the same year use their girders in entirely different ways: the Kumagawa Railway Omizo Bridge saves space underneath, while its neighbour carries a standard plate girder in the conventional way.

Visiting

The Kumagawa Railway Omizo Bridge is in daily service, and the track is off limits. You view it from the surrounding streets, free of charge. Hitoyoshi Onsen Station, next to JR Hitoyoshi Station and home to the Kumagawa Railway ticket counter, is about 310 metres to the west.

No specific restriction on photography from public roads has been announced, but stay out of fields and private land, and step well back when a train approaches.

📍 Plan Your Visit to Kumamoto: Find tours, activities & transport passes near Kumagawa Railway Omizo Bridge; [ Kumamoto Castle & Mt. Aso Volcano Tours ]

Q&A

QWhere is the Kumagawa Railway Omizo Bridge and what is the nearest station?: AIt is in Shiromotomachi, Hitoyoshi City, about 310 metres east of Hitoyoshi Onsen Station, the western terminus of the Kumagawa Railway.

QCan I see the Kumagawa Railway Omizo Bridge up close?: AIt is a working railway bridge, so the track is off limits. You can view the exterior from nearby roads at no charge.

QWhat is special about the Kumagawa Railway Omizo Bridge?: AThe rails sit in the trough between two main girders, and they are mounted on longitudinal timbers, a detail from the earliest standard designs.

QWhen was the Kumagawa Railway Omizo Bridge registered as a cultural property?: AIt was registered on 19 December 2014 together with the other structures along the line, under registration number 43-0130.

QCan I take photographs of the Kumagawa Railway Omizo Bridge?: ANo specific restriction on photography from public roads and other permitted places has been announced. Do not enter the track, fields or private land. Commercial filming and press coverage go through the Kumagawa Railway's filming and coverage request page.

Basic Information

Name	Kumagawa Railway Omizo Bridge (くま川鉄道御溝橋梁)
Location	Torioka to Daio, Shiromotomachi, Hitoyoshi City, Kumamoto Prefecture
Designation	Registered Tangible Cultural Property (structure), registration No. 43-0130
Year Designated	Registered 2014/12/19 (Heisei 26)
Quantity	1 structure
Dimensions	Steel single-span girder bridge, 4.8 metres long, with abutments
Owner	Kumagawa Railway Co., Ltd.
Public Access	In railway service; no access to the track, exterior visible from nearby roads