THE TUNNEL OF THE FUTURE CIRCULAR COLLIDER COULD REACH A DEPTH OF 400 METRES IN SOME PLACES, WHICH IS EQUIVALENT TO THE HEIGHT OF THE EIFFEL TOWER

The excavation of this tunnel, which would be done in a layer of rock located under the Franco-Geneva region, and the construction of the associated surface infrastructures would constitute a huge civil-engineering challenge and would require international research and development on tunnel excavation methods and the reuse of the excavated materials. 

Shafts with a diameter of 15 metres, corresponding approximately to the footprint of a single-family house, would provide access to the tunnel from the surface. As well as the accelerator, the tunnel would house all the electrical installations and cabling necessary for the routing of data and for the remote controls, which would greatly reduce the scale of the surface infrastructure.