Abstract: A method and apparatus for forming a spiral tube from a length of metallic strip material wherein the strip is fed through a closed tube forming die operative to form the strip into a spirally wound tube having its longitudinal edges in juxtaposed relation. Driven torque wheels carried on one or more support carriages downstream from the forming die are operative to engage the outer peripheral surface of the tube to prevent springback and enable selective control of the relation between juxtaposed edges of the strip as it is passed longitudinally through a welding station during which the juxtaposed edges are welded to form a continuous leak-proof seam. The metallic strip may be planar or have longitudinal flutes formed therealong.

Abstract: A method and apparatus are disclosed for banding a vertical wall of a large vessel with a highly tensioned tendon payed out from a traveling carriage being driven about the vertical wall. The carriage is suspended from the structure and a circumferential restraining means constrains a primary set of traction wheels driven by a primary hydraulic system and a second set of wheels driven by regenerative hydraulic system into frictional engagement with the vessel wall. The preferred wheels comprise hydraulic motors having an outer rotatable portion or race to which is directly attached an encircling tire. A tendon tensioning mechanism is disclosed with restraining elements having outer frictional surfaces engaging the tendon without slipping and having other frictional surfaces for slipping relative to a force applying means when accommodating elongation of the tendon during tensioning.

Abstract: A method and apparatus are disclosed for circumferentially banding a circumferential wall of a large vessel with a highly tensioned tendon. The carriage is suspended from the top of the structure and constrained into contact with the wall to travel circumferentially about the vertical structural wall. The carriage is propelled forwardly during banding against the large restraining force, e.g., 30,000 lbs. or more, from the tendon which is connected to the wall by a belt drive means on the carriage which is in driving engagement with upper and lower belts looped about the vessel and extending through the carriage. The belt drive means comprises belt drive drums about which the belts travel after being lifted from the structural wall at the forward end of the carriage. The belts are returned to the structural wall at the rear end of the carriage.