Hitachi Zosen Corp. showed to the press Tuesday what it claims to be the world's largest shield tunneling machine at its Sakai plant in the Osaka area.
The 110-meter-long machine, with a diameter of 17.45 meters and weighing some 7,000 tons, will be used to drill a 2,800-meter highway tunnel in Seattle to replace an aging elevated highway, the company said.
Hitachi Zosen said it began making this kind of machine in 1967 and has delivered more than 1,200 units to customers in and outside Japan.
The company said it is hopeful the newest machine, due to be shipped to the port of Seattle by late March, will help it win more business abroad.