NTT Kuramae Cable Bridge, Cable bridge in Sumida-ku, Japan

The NTT Kuramae Cable Bridge (Kuramae Sen'yō-kyō) is a three-span continuous steel box girder bridge over the Sumida River, linking Kuramae 1-chome in Taito ward with Yokoami 1-chome in Sumida ward. Completed in March 1967 and opened in 1968, it is 155.4 m long with a 55.0 m main span and 342.0 t of steel. It is Japan's first bridge built solely to carry a telecommunications cable tunnel, and it also serves as a water main crossing.

Built in March 1967 and opened in 1968, the bridge dates from the era of the former Denden Kōsha, the public telegraph and telephone corporation, which is why it was also called Denden Kuramae Bridge. The Tokyo Telecommunications Bureau and the Tokyo Metropolitan Waterworks Bureau commissioned it, with the superstructure by Kawasaki Heavy Industries and the substructure by Shiraishi Kiso Kōji. It was strengthened against earthquakes in 2009.

The bridge takes its name from NTT, whose Kuramae telecom building it links to the opposite bank; in the era of the former Denden Kōsha it was also called Denden Kuramae Sen'yō Bridge. It is a private crossing for authorised staff, so the public cannot walk onto it. Its deck also carries a water main alongside the cable tunnel.

The bridge is closed to the public: it is reserved for NTT personnel, so you cannot walk onto the deck. It stands just south of Kuramae Bridge, linking the NTT Kuramae telecom building on the Taito side with the opposite bank in Sumida. Views of its steel box girders come from the Sumida River banks and from neighbouring bridges.

It is Japan's first bridge built solely to carry a telecommunications cable tunnel, and it also serves as a water main crossing. Ventilation windows in the tunnel walls handle summer heat. Because it is reserved for authorized personnel, nobody can walk onto the deck.