Construction

Honouring the crown mockup

Medieval stone masons used to engrave their personal mark on the walls and pillars of the cathedrals they contributed to building. Their present-day counterparts, the builders of ITER, did something equivalent last week: with felt-tipped markers in place of chisels, all the men and women involved in the realization of the Tokamak's supporting "crown" scrawled their signature on the smooth concrete of the mockup that had made the crown possible.
Designed to provide the ultimate demonstration of the crown's constructability, the mockup, like the crown it prefigured, was a collective masterwork.
Brief but highly symbolic, the event gathered a few dozen personnel from the BIPS Project Team (Building, Infrastructure and Power Supplies), architect-engineer ENGAGE, the ITER Organization, the European Domestic Agency Fusion for Energy and its contractors¹. Like the crown it prefigured, the mockup was a collective masterwork.
 
The construction of the mockup during the summer of 2017 was made necessary by the complex and strategic nature of the Tokamak's supporting crown. Representing a true-size 40-degree section of the projected structure, the mockup—with a footprint of 50 m² and a height of 3 metres—was to be the ultimate demonstration of the crown's constructability.
 
Like stone masons in medieval times, the builders of ITER left their personal mark on the collective masterwork.
In his address to the small audience, Director-General Bigot stressed its importance in the successful realization of the crown—a challenging structure characterized by unique geometry, high-density steel reinforcement and high-performance concrete.
 
The crown was successfully finalized last autumn, and the mockup's mission has been fulfilled. Because space on the ITER platform is always scarce it may one day be demolished. In the meantime, it deserved to be honoured for its significant contribution to the project.
 
¹Tiresia, Energhia, Nuvia, and APAVE (heath and safety).