Abstract: A method for manufacturing a large basically spherical vessel from plane aluminum plates having a thickness in the range from about 20 mm to about 70 mm, comprises (a) forming at least first and second plane plate assemblies by downhand welding together plane plates controlled by a welding device including an adjustably lockable portal, (b) cutting each welded plane plate assembly to a peripheral shape that fits into the structural pattern of the vessel except for an allowance for machining in step (d), (c) bending each plate assembly to part-spherical configuration, (d) machining respective edges of the first and second bent plate assemblies to a profile suitable for welding in step (e), and (e) downhand welding the first and second plate assemblies together along the machined edges using a manipulator device that includes a tiltable support.

Abstract: The invention relates to a device to machine workpiece edges with variable dimensions using a device for clamping the workpieces and a machining unit, whereby the device according to the invention is characterized by a first clamping bed with a clamping plate for clamping the workpiece surfaces, a second clamping bed with a clamping plate for clamping the workpiece edges hanging over the first clamping bed and means to change the position and the orientation of the first clamping bed relative to the second clamping bed.

Abstract: A plate body is formed from two plane metal plates each at least 5 mm thick and having an edge at least 10 meters long, by machining each plate along its edge to form a welding groove with high accuracy relative to the dimensions and shape of the groove and with a smooth groove surface. The groove extends from a first side of each plate through only part of the thickness of the plates to leave a root area at the second side of the plate. The plates are supported in the vicinity of the welding groove from the second side of the plates by a support bed and are retained by use of suction in relative positions such that the root areas of the two plates are in confronting and contacting relationship. A weld is created in the welding groove by butt joint welding from the first side only of the plates.