APPARATUS AND PROCESS FOR IMPROVED MANUFACTURE OF SHELLS FOR TUNNEL TUBES

摘要

This invention relates to improved apparatus and process for manufacture of tunnel modules and tunnel sections used to build underwater tunnel tubes. A collapsible fixture is used to roll-up a flat steel plate into a cylindrical shell for the tunnel modules. A hydraulic cylinder is utilized to adjust the diameter of the fixture without collapsing it in order to close any gaps between the ends of the plate when it is rolled into a shell.