The operator of the Tokyo Metropolitan Expressway is removing concrete ceiling panels from a tunnel near Haneda airport after discovering defective fasteners during emergency checks ordered after similar panels killed nine people in a tunnel in Yamanashi Prefecture earlier this month.
Metropolitan Expressway Co. began the work on Saturday and will have all 684 of the massive panels down by Thursday, it said.
The tunnel near Haneda has the same suspended ceiling structure as the Sasago Tunnel on the Chuo Expressway, which collapsed Dec. 2, killing nine motorists in a cloud of debris about 80 km west of Tokyo.
These are the first ceiling panels to be removed from an operational expressway tunnel, said the company, which is one of six that manage such tunnels.
West Nippon Expressway Co. plans to remove concrete ceiling panels from three tunnels in Okayama, Hiroshima and Yamaguchi prefectures, while East Nippon Expressway Co. is still carrying out inspections to determine whether removal is necessary.
The tunnel near Haneda airport opened to traffic in 1964 and is 300 meters long. The area in doubt is just 20 meters long but has ceiling panels suspended over opposing lanes of traffic.
Each of the narrow ceiling panels is 2.6 meters long, 40 cm wide and 5 cm thick and weighs 130 kg.
The Land, Infrastructure, Transport and Tourism Ministry ordered that expressway tunnels be inspected immediately and ahead of the yearend and New Year holidays, when traffic increases substantially.