Sector repair has started

With a precision of 0.05 millimetres, laser metrology has mapped the geometry of every section of the bevel affected by dimensional non-conformities. For each section the data obtained is made available to the welder, both as a printed document and as markings embossed on the component itself.

A welder is building up metal along a section of the bevel region. Reference and guiding documents are visible on the right, taped to the red, semi-transparent plastic curtain thta protects personnel on the outside from the blinding light of the torch's electric arc. Four welders are operating at different levels.

For an experienced welder a build-up operation is simple, almost routine. However, it requires extreme concentration to achieve regularity and homogeneity in the successive deposit of the small beads that form a "pass."

Some 20 metres above the shop floor, at the top level of scaffolding, two platforms protrude from the main structure to provide workspaces for welders. At regular intervals during the build-up process, quality control specialists come by to inspect the work performed by the welders. Operations on sector #7 are not the only activities in the Assembly Hall: also visible to the right of this image, a team on the ground is preparing to stack a third central solenoid module.

A welder checks the temperature of the pass he completed a moment before. He will not proceed to make another pass before the temperature falls below 116 °C.

Seen from below: two automatic machining tools are positioned to rectify affected bevel sections at the bottom of the sector. Components for the machining tools are standard but they are assembled here in a way that combines lightness and rigidity.

Machining tools are programmed to follow a precise trajectory along the bevel area. Here, specialists from Metalock Engineering UK, contractor to the SIMANN consortium (SIMIC/Ansaldo Nucleare), are fine-tuning the initial positioning of the tools prior to actual machining.