Sumidagawa Bridge, Railway bridge in Sumida-ku, Japan

Sumidagawa Bridge is a railway bridge on the Sobu Main Line between Ryogoku and Asakusabashi stations. Its 172 m steel structure has three spans of 38 m, 96 m and 38 m; the central span is a Langer girder, the first of its kind in Japan, with an arch above the deck.

The bridge opened in 1932 as part of the Sobu Line expansion, creating a new rail connection for Tokyo's growing districts. Its construction marked an important step in improving train access across the city during the early Showa period.

The bridge structure reflects early Showa period engineering methods, featuring a Gerber girder system with three spans in the Langer design.

This bridge carries train traffic only and is not accessible to pedestrians, as it was built exclusively for rail use. The best views of its structure can be found from the eastern or western riverbank.

The bridge's central span uses a Langer girder, a stiffened arch carrying load through both the girder and the arch; it was the first use of this type in Japan. The design came from engineer Tanaka Yutaka, and the steel superstructure was built by Yokogawa Bridge Works, weighing 1,365 tonnes.