Final dimensional test with alu-jig travelling through the CMS Inner vacuum tank

The inner vacuum tank is an object of 13m lenght and 6m diameter that is completely made of stainless steel SS304. To allow insertion of the inner detectors, especially the hadronic calorimeter, a rail at 9 and 3 o'clock position is integral part of the cylindrical tank. To insert, weld and finally machine this rail was a big challenge for the manufacturer. The dummy jig presented on the pictures represents the diameter of the most outer corner of the hadronic calorimeter plus a scintillator and some cables.