Outdoor ballet
Under clement skies and with millimetre precision, ITER assembly teams once again carried out a rare heavy-lifting operation outdoors, rotating a 400-tonne vacuum vessel sector using a temporary gantry crane.
For the third time, the ITER machine assembly team has used an outdoor gantry crane to expose the underside of a recently delivered vacuum vessel sector.
The challenge in 2025 was logistical as much as technical. With vacuum vessel assembly back underway, the Assembly Hall’s lifting and handling equipment was already fully committed to the transport, upending and positioning of sector modules under construction. Freeing up the equipment needed to rotate newly arrived sectors would have risked slowing assembly progress and reducing the schedule gains teams had built against the ITER Baseline.
Instead, engineers devised an alternative solution: move the operation outdoors.
Weather permitting, teams could temporarily install a gantry crane capable of lifting 400 tonnes and perform the rotation in open air. Twice in 2025, and again last week, this all-day operation was successfully carried out under the most stringent safety conditions.
For the first two sectors, temporary lifting lugs had to be welded onto the components before rotation could begin. This time, however, the European Domestic Agency anticipated the operation and welded the lifting lugs onto vacuum vessel sector #3 before it left the factory. As a result, the sector could be rotated just six days after arriving on site.
With the rotation complete, vacuum vessel sector #3 has now returned to a workshop on site for repair to its bevel joint surfaces before rejoining ITER’s advancing machine assembly campaign.
See the 12-hour rotation operation sped up to a few seconds, below.
