Marks for Assembly (GSD)

This document is a detailed description of the use of assembly marking - GSD, Gütesicherungsdreiecke ("Quality assurance triangles") within the Hull application.

One of the major shipyard requirements is to reduce the need for additional fitting in the assembly process and thus reduce the production time. One way of doing this is to increase the accuracy of the fabrication at part level by introducing new technology and equipment. Another method is to increase the accuracy in the assembly process, preferably at each step so that the accumulated errors are reduced. An important means to facilitate improved accuracy in both fabrication and assembly is the use of assembly marks (GSD). These are used both for alignment in the assembly process and for checking of accuracy after assembly.

There are two kinds of GSD:s. One is a symmetric triangle with 90 degree angle and the other is a straight line. In general the illustrations in this document show, with few exceptions, triangular GSD:s. It is not possible by looking at an isolated GSD to determine which of the two "tips" or ends that is significant, for example, for a marking line. Thus the use of a GSD is defined by the context in which it occurs.