Nine months after work began, the excavation of the two new shafts for the High-Luminosity LHC has been completed. On the site of the CMS experiment (LHC Point 5) at Cessy, a 60-metre shaft with a diameter of 11 metres was fully excavated before the end of 2018. On the site of the ATLAS experiment (LHC Point 1), the 62-metre shaft has just been completed and the contractors are installing a concrete ring at its base. With this first phase of the underground work now complete, the contractors are starting to excavate the 50-metre-long underground halls, which will be 17 metres wide and 17 metres high. This work should last about four months. A number of service tunnels will then be constructed on each site, one of them 300 metres long to house equipment and four of them 50 metres long to connect the new structures to the LHC tunnel.

* © Antonino Panté, antoninopante.com. Reproduced with permission.