Tokyo Bay Aqua-Line/Undersea tunnel ventilation system (Japan)
Ventilating the world's longest undersea tunnel to provide a safe and comfortable driving environment
Courtesy of Trans-Tokyo Bay Highway Corporation
Opened in 1997, the 15 km-long Trans-Tokyo Bay Expressway (Tokyo Bay Aqua-Line) connects Chiba and Kanagawa Prefectures. The Aqua Tunnel, which crosses the seabed of Tokyo Bay, occupies approximately 10 km of this expressway. It is the longest underwater tunnel in the world and is equipped with EBARA ventilation systems. In road tunnels, natural ventilation is provided by natural wind caused by the pressure difference between the two shaft openings and by the flow generated by the piston action of traveling vehicles.
Courtesy of Trans-Tokyo Bay Highway Corporation
In such road tunnels, where natural ventilation alone is not enough to respond to conditions such as an increased amount of required ventilation due to an increase in traffic volume, mechanical ventilation is provided by installing ventilation systems. The Tokyo Bay Aqua Tunnel has a special structure with the cross-section of the tunnel divided into two upper and lower layers by floor slabs for disaster prevention, and the tunnel diameter is 14 m. Utilizing the ventilation power of traffic, a low-cost, energy-saving ventilation system was employed, and we developed two exhaust fans with a diameter of 4 m, two fans under the floor slab, and their auxiliary systems.The Tokyo Bay Aqua-Line has brought many benefits, including easing traffic congestion in the city center and improving industrial activity.We are committed to provide safe driving environment.
