A Proposal on Modernization of Assembly Line of Curved Panel Units of Ship's Hull (1 st Report)

Abstract

This report deals with the specific methods for modernization of the assembly line of the curved panel units.One of the vital problems in the modern shipbuilding industry is the modernization by means of mechanization and automation, to overcome insufficient labor sources in the recent years, during the hull assembly process. Conventionally, the modernization of the hull assembly process has been achieved mainly by the automation of the welding, but it has been limited to be applicable to the flat panel units only. However, the hull, as its movements are much related to the stream-line, the adoption of the stream-line is indispensable, and the fore and the aft parts of the hull naturally include the curved panel units. These curved panel units usually are made up with three dimensional faces, furthermore, each unit has different shape and arrangement. For this reason, it has been considered impossible to apply the mechanization and the automation, and the assembly work has had to rely on the skilled workers, therefore, at present it requires more skilled workers than in the case of work on the flat panel units. Also, in consideration of adoption of the flow line production system for the assembly process, the work is often interrupted by the dangerous turn-over of the units for the safety's sake, which causes considerable occasions of waiting time, one of obstacles in the flow line production sytsem for the assembly process.From the viewpoints mentioned above, the authors have conducted checkings for the modrenization in extensive fields of the assembly processes of curved panel units, and as its first stage, we developed the automatic assembly apparatuses for the curved panel, composed of the forming jack device, the welding positioner, and the one-side automatic welding machine.