The improvement of productivity in response to changes in the labor force--related largely to a decreasing number of skilled workers--has become a major concern of production engineering in shipyards. The following problems were pointed up by an analysis of production tasks:
Most work time is wasted in the repair or adjustment of inaccuracies, such as wide gap, lap, or deformation in structural components, which are accumulated at the preassembly stage.
lf the accuracy of fabrication and assembly of hull structures is measurably improved, productivity will rise respectively, and effective mechanization and automation of production can be achieved.
The research and development of new hull block production systems based on the above concept--accurate production---have started at lshikawajima-Harima Heavy Industries Co., Ltd. (IHI). Advanced accuracy standards were planned for the new procedure of hull block assembly, and a new "unit-panel and slit process" has been developed and applied at the IHI shipyard. This paper describes the accuracy control system and the new production line at the IHI yard, as well as some key equipment for the installed process.