How to Fill a Narrow 27 km Long Tube with a Huge Number of Accelerator Components?

As in large scale industrial projects, research projects, such as giant and complex particle accelerators, require intensive spatial integration studies using 3D CAD models, from the design to the installation phases. The future management of the LHC machine configuration during its operation will rely on the quality of the information, produced during these studies.This paper presents the powerful data-processing tools used in the project to ensure the spatial integration of several thousand different components in the limited space available.It describes how the documentation and information generated have been made available to a great number of users through a dedicated Web site and how installation nonconformities were handled.