The civil engineering works is progressing well (the detailed progress status is shown in Figure 1). The underground works, including the metallic structures, have been fully completed at Point 1 in October 2021 and Point 5 in February 2022, with only one to two months of delay with respect to the contractual dates mainly due to the COVID-19 impact.
Figure 2 shows the US/UW and the UR gallery at Point 5. Today, the main civil engineering activities are concentrated on the surface works. The two first standalone buildings – the cooling tower buildings (SF) and the cryogenic compressor buildings (SHM) – have been delivered end of June 2021 at Point 5 and end of October 2021 at Point 1. The construction of the remaining cluster of 3 buildings – the ventilation buildings (SU), the electrical buildings (SE) and the shaft-head buildings (SD) – are well advanced. The SU building has been delivered end of April 2022 at Point 1 and the SU building at Point 5 is expected to be delivered end of August 2022. The final deliveries of the civil engineering works are expected by September 2022 at Point 1 and by December 2022 at Point 5 also with one to two months of delay with respect to the contractual dates mainly due to the COVID-19 impact. These identified delays have minor impacts on the HL-LHC master schedule.
The installation of the technical infrastructures has started following the deliveries of the buildings. It concerns the installation of general services like lighting, sectional doors, cable trays, overhead cranes, ventilation, water for firefighting, and the fire detection and its protection/evacuation system. The installation of general services is close to completion at Point 1 and Point 5 in the SF buildings. Works are ongoing in the SHM buildings which should be fully equipped by the end of 2022 and has just started in the newly delivered SU17 building. Figure 3 shows a SHM building with its general services.
In addition to the general services, the installation of the machine infrastructures has started in the two SF buildings. This includes the installation of the primary-water cooling system and of the associated cooling towers. These systems are expected to be commissioned by the end of 2022. Figure 4 shows an SF building with its general services and its primary-water cooling infrastructure under installation.
In the beginning of 2023, the installation of technical infrastructures will start in the SD and SE buildings as well as in the underground structures (PM shafts, US/UW caverns and UR/UA/UL galleries). The main part of the technical infrastructures should be installed by the end of 2024. Then, the remaining installation activity will resume after the delivery in summer 2026 of the 24 vertical cores which will link the HL-LHC structures with the LHC tunnel. The vertical-core excavation is expected to start in December 2025 (present LS3 start date). A pre-excavation during the EYETS 2024-25 to alleviate schedule constraints in the LHC tunnel at the beginning of LS3 is currently under study.
