The central solenoid will be assembled from six cylindrical modules stacked one on top of the other. Weighing 110 tonnes and standing 2 metres high, each module is massive in its own right.
The first sequence of central solenoid assembly will be to install the three lower modules on top of the key blocks. These lower modules will be attached to their source of power through heavy steel-jacketed busbars (which also supply liquid helium for cooling through specialized joints) before the next three modules are added.
Once all six modules are stacked and joined to their extensions, the upper key blocks will be put on top of the last module, and tie plates—each about 15 metres long—will attach the upper key blocks to the lower key blocks. Eighteen tie plates will be used on the outside and nine on the inside, creating a powerful support cage.
The stacking process requires lifting and then accurately positioning these cumbersome objects. The team will use special tools designed and developed by US ITER* as well as highly accurate measurement devices and techniques to align components and make sure the composite magnet is level to within a few millimetres.
Full article: https://www.iter.org/newsline/-/3837