Kyobashi Water Pipe Bridge

A Meiji Water Bridge over the Asahi River

Kyobashi Water Pipe Bridge (京橋水管橋, Kyōbashi Suikankyō) is a steel bridge built in 1905 to carry water mains across the Asahi River in Okayama City, Okayama Prefecture, linking Kyobashi-cho in Kita Ward with Nishinakajima-cho in Naka Ward, and it was registered as a Registered Tangible Cultural Property of Japan in 2005. It stands just upstream of the Kyobashi road bridge, and it was never meant for people or vehicles.

Okayama opened its piped water supply in 1905, the eighth modern waterworks in Japan after Yokohama, Hakodate, Nagasaki, Osaka, Tokyo, Hiroshima and Kobe. Water treated on the west (right) bank had to reach districts on the east bank, which meant a pipe crossing over the river. The Kyobashi Water Pipe Bridge is that crossing. A photograph kept by the Okayama City Waterworks Bureau shows work on its abutments in 1904, with the old timber Kyobashi beside the site.

That timber road bridge is the reason the pipes did not simply hang off Kyobashi. The engineers built a separate steel bridge instead, and Okayama Prefecture's description links this choice, together with the design of the piers, to concern about floods.

Why It Was Registered

The bridge was registered on February 9, 2005, as registration no. 33-0100, under the criterion of being difficult to reproduce. Structures from the Handayama reservoir, including its meter rooms and former office, were registered on the same day, so a century after the first water flowed, Okayama's founding-era waterworks were recognized together.

The Agency for Cultural Affairs counts the Kyobashi Water Pipe Bridge among the earliest steel bridges built for a water supply in Japan. It is a five-span Truss bridge of the Warren type, with parallel top and bottom chords and diagonal members forming a run of triangles. The Agency gives a length of 131 meters, the Waterworks Bureau 131.2 meters, and the longest span is 33 meters. The members are riveted, with flat bars and angle sections used in different parts of the frame, and the bridge crosses the current at a skew rather than square.

The four piers are as interesting as the trusses. They are concrete, pentagonal in plan, bound with iron bands, and sheathed at the corners with steel plate. The Waterworks Bureau explains the cutwaters and corner plates as protection against driftwood striking the piers in flood, and the Agency singles out the construction as unusual.

Two Iron Bridges Side by Side

The clearest view of the Kyobashi Water Pipe Bridge is from the riverbank at the west end of Kyobashi, looking upstream. The slim steel triangles run straight to the far bank with the pipe carried inside them. With no deck for traffic, the whole structure is on show.

Immediately downstream is the present Kyobashi, rebuilt in 1917: a road bridge whose steel girders rest on clusters of steel tube columns, now listed by the Japan Society of Civil Engineers as civil engineering heritage. The Waterworks Bureau describes the two as a striking contrast and an important part of the historic river scene. From one spot on the bank you can set a light Meiji truss beside a heavy Taisho girder bridge and compare them.

Go down near the water and look at a pier: the pentagonal plan, the plated corners and the iron bands are all easy to pick out. The Higashiyama tram line also runs across Kyobashi, so passengers get a brief look at the trusses from the window.

Visiting

The Kyobashi Water Pipe Bridge belongs to Okayama City, and the Okayama Prefectural Board of Education lists it as exterior viewing only. It carries water mains, so it cannot be walked across. You can see it free of charge from the Kyobashi sidewalk or from the riverbanks on either side. Nothing found restricts photography from public spaces, but please do not climb onto the bridge or cross any barriers.

From JR Okayama Station, take a tram bound for Higashiyama and get off at Saidaijicho, a ride of roughly 7 to 10 minutes. The Okayama Tourism and Convention Association puts the walk from the stop to the riverside at the west end of Kyobashi at about 3 minutes. When the Asahi River is running high after rain, stay on the bridge deck of Kyobashi rather than going down to the riverbank.