上淀川橋梁

Gazing at the Kami-Yodogawa Bridge, it’s hard to imagine its complex history. This unassuming steel giant, spanning the new Yodo River, has witnessed over a century of Osaka’s evolution. Kami-Yodogawa Bridge connects Shin-Osaka and Osaka Stations on the Tokaido Main Line. It’s actually a triple-layered steel railway bridge, stretching an impressive 729.3 meters. Looking upstream, you can see the intricate layers. The lowest is the Tokaido Main Line down track. Above that are the up and down tracks of the Umeda Freight Line. And at the top, the Tokaido Main Line up track. The bridge’s history intertwines with the story of its predecessor, the Kamijuso Bridge. Built in 1876, Kamijuso Bridge was a crucial part of the first railway line between Osaka and Kyobashi. This initial bridge was designed by John England, a prominent British engineer in Japan at the time. The original bridge spanned the old Yodo River, which split into three narrow, winding rivers. After a major flood in 1885, the river was rerouted, creating the new Yodo River. Kamijuso Bridge was dismantled in 1901 to make way for the new Kami-Yodogawa Bridge. Construction on the Kami-Yodogawa Bridge began in 1900. The new bridge utilized twenty-two 100-foot Pratt truss spans from American Bridge Company, chosen for their ability to handle heavy loads. The lower structure used masonry and concrete, with stone in the underwater sections. The bridge was completed in 1901, showcasing a mix of American and Japanese engineering. In 1928, an additional layer was added to the Kami-Yodogawa Bridge to accommodate the Umeda Freight Line. This layer also used Pratt truss spans but were domestically produced, marking a shift towards Japanese bridge manufacturing. Further expansion occurred in the 1930s with the addition of a third layer. This layer employed plate girders instead of trusses, a decision driven by cost and ease of construction. Construction was interrupted by World War II but ultimately completed in the 1950s. Since then, Kami-Yodogawa Bridge has undergone various modifications and reinforcements. These interventions were necessary to address ground subsidence and comply with new river regulations. Even today, the bridge continues to be maintained, with the replacement of the upper flange starting in 2009. So, next time you cross Kami-Yodogawa Bridge, remember its long and layered past. It’s a testament to Osaka’s resilience and adaptability, a steel narrative woven into the city’s fabric.