Definition of Deformations and Stresses of Large Ship Blocks within Transportation and Manipulation

Abstract

Deformations and stresses during the transport and manipulation of large ship blocks within ship assembly and erection stages are a common and significant issue, particularly in the construction of complex ships and variable production mix, as is the case in many European shipyards. The appearance of deformations and stresses requires adequate addressing with the aim of their early determination and reduction with a goal to reduce a significant number of working hours spent for the large ship blocks transport preparation, for the transport and manipulation itself, and for the reworks. The appearance of residual stress in blocks that are not adequately addressed can be an issue in the exploitation, reducing the quality and ship service life. In this paper, the authors present the procedure of determining deformations and stresses in the large ship block. The procedure is based on computer modelling and numerical analysis of the selected ship block. Various scenarios of the foundations' arrangement and the arrangement of the transport hooks were analysed, and the optimal solutions were proposed. The procedure allows determining deformations and stresses at an early stage of ship technology design to define the adequate preparation for ship block foundations layout, transportation and manipulation before production starts. In doing so, it is expected to reduce deformations and stresses itself, necessary working hours for block accommodation, transportation and manipulation and to reduce repair works. Such procedure application is expected to raise the efficiency of the overall ship production process and the quality of the final product. Finally, further research is proposed regarding various scenarios of technological procedures, ship blocks structures or used materials.