The production of non-planar coils for the Wendelstein 7-X experiment: A (self-) critical review

Babcock Noell (BNG) is producing 2 types of non-planar coils for the Wendelstein 7-X experiment which is presently under construction in Greifswald: As part of the Consortium Wendelstein we fabricate 50 non-planar superconducting modular field coils for the main magnetic cage of the plasma and as sole contractor we build 10 resistive control coils to be installed in the plasma vessel. The end of the fabrication and the delivery of the last coil in both orders are expected to take place by spring 2008. We want to review the production and project management processes from the manufacturer's point of view. Following a presentation of the main components and production steps we discuss the effects of the modifications and changes that were introduced during the project progress on the fabrication process, the fabrication sequence and the schedule as well as the problems that were encountered, how they had been solved and their effects on the aforementioned data. Taking into account the lessons that we learned in this project, we present our conclusions for procedures to be applied to future large scale projects.