As heavy as a 747 and (almost) as airworthy
In the ITER Assembly Hall, two giant sector sub-assembly tools (SSAT) provided by Korea are tasked with preassembling some of the most massive components of the Tokamak. Over the past two months, functional tests under load were performed and completed on the first of the tools. With the transfer last week of the loads to tool #2, the same operations are about to be repeated.
Over the past two months, functional tests under load were performed and completed on the first of the two giant sector sub-assembly tools (SSAT). With the transfer last week of the loads to tool #2, the same operations are about to be repeated.
The SSAT tools will support 440-tonne sectors of the vacuum vessel in their centre as they are pre-assembled with two D-shaped toroidal field coils and thermal shield panels.
In order to test the full range of the tool's functions, two 360-tonne dummy loads—representative of the weight, general shape and centre of gravity of a toroidal field coil—are lifted onto the tools' lateral structures, and positioned and aligned with utmost precision.
The second 360-tonne load was transferred last Thursday 26 September to SSAT#2. The tool's particular configuration made the operation a delicate one: the temporary wall that separates the Assembly Hall from the Tokamak Building constrains the tool on its right side and prevents the full opening of the lateral wing.
Because of this configuration, and also because the load had to be moved from one tool to the other, the lifting clearance was exceptionally tight—no more than 20 centimetres on each side of the test load structure.
With approximately two dozen specialists involved and a large logistical team in the background, the operation, condensed here in a time-lapse video
, took the better part of the day.
With its frame now bearing the weight of two dummy loads, the second tool will be submitted to approximately one month of functional tests. Shortly before Christmas the loads will be removed and stored pending the assembly of the "upending tool
," whose parts should arrive at ITER in October
. Early next year, the upending tool should be ready for functional tests with the same dummy loads.
Once "upending" tests are complete, the two 360-tonne loads will have one final service to render—the testing of the Assembly Hall's double overhead crane once the crane hall
over the Tokamak Building is completed and the crane rails are extended over the Tokamak pit.
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